Abstract

Imaging with THz radiation has proved an important tool for both fundamental science and industrial use. Here we review a class of THz imaging implementations, named coherent lensless imaging, that reconstruct the coherent response of arbitrary samples with a minimized experimental setup based only on a coherent source and a camera. After discussing the appropriate sources and detectors to perform them, we detail the fundamental principles and implementations of THz digital holography and phase retrieval. These techniques owe a lot to imaging with different wavelengths, yet innovative concepts are also being developed in the THz range and are ready to be applied in other spectral ranges. This makes our review useful for both the THz and imaging communities, and we hope it will foster their interaction.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

1. INTRODUCTION

Terahertz (THz) radiation denotes the portion of the electromagnetic spectrum whose frequency ranges from 0.1 THz to 10 THz, lying between the infrared and microwave regions [1]. As such, its interaction with matter shares properties of both neighboring bands. Like microwaves, THz waves can penetrate insulating materials, such as building and plastic materials [25], intrinsic semiconductors [6], paper [7], and fabrics [8]. Owing to the shorter wavelength compared to microwaves, THz waves offer a higher spatial resolution, paving the way for new non-destructive tools for industrial inspection with sub-mm resolution [9]. Like the infrared band, the THz band is host to a wide variety of energy transitions in aqueous [10] and solid-state systems [11], making THz radiation a valuable probe to investigate fundamental properties of matter, as well.

In order to fully exploit this potential, it is crucial to develop imaging techniques using THz radiation. Research on THz imaging has been growing for more than 20 years [12,13], and its advances go hand in hand with the improvement of THz sources and detectors.

In particular, ultrafast lasers enabled the development of broadband THz sources and coherent detectors [14]. Along these lines, imaging with THz time-domain spectroscopy (THz-TDS) [15] has found widespread use in both industrial [16] and scientific applications [17,18]. In the latter case, it is worth mentioning its use in near-field setups breaking the diffraction limit [19,20]. The most important advantage of imaging with THz-TDS is its ultrafast detection, which allows direct measurement of the time evolution of the THz electric field, so that the complex refractive index of the object can be extracted [21]. This comes at the expense of the flexibility of the setup, which should always feature synchronization between source and detector. Furthermore, manufacturing detector arrays with usable size for full-field imaging is currently prevented by the need for high-power (Watt-level) femtosecond lasers, thus limiting THz-TDS imaging as a scanning technique [22,23]. The use of THz-TDS towards real-time imaging has been recently reviewed by Guerboukha et al. [13].

Other THz imaging techniques borrowed their operational principle from techniques implemented at shorter wavelengths, from the visible to the x-ray range. THz tomographic techniques are a valuable solution to obtain non-destructive three-dimensional (3D) reconstructions of weakly absorbing samples [24], either from projections taken at different angular positions [25] or in a confocal microscopy arrangement in reflection mode [26], where in both implementations, the acquisition can be made coherent with the addition of a reference arm. Compressive sensing is a smart computational imaging concept, where the beam transmitted through the object is modulated with a carefully designed mask, and the resulting intensity is recorded with a single-pixel detector. Provided that the object transmission function or its gradient is sparse, its reconstruction is allowed from a number of measurements lower than the number of unknown pixels [27]. First demonstrated with a THz source by Chan et al. [28,29], it represents a cheaper alternative to imaging techniques using THz cameras, although it imposes stringent requirements on the object transmission function.

Imaging techniques delivering coherent reconstructions of arbitrary objects, with flexible and compact setups and using cameras, belong to the realm of coherent lensless imaging (see, e.g., [30]). The fact that cameras are not fast enough to record both the amplitude and phase of the electric field impinging on them leads to the so-called “phase problem,” which entails extracting the missing phase information from intensity-only measurements. Upon illuminating the object with a spatially and temporally coherent beam, coherent lensless imaging techniques solve the phase problem using one or more diffraction patterns of the object (with iterative algorithms referred to as “phase retrieval” [31,32]), or their interference with a known reference wavefront (holographic techniques [33]). Because they obviate the need for imaging components such as lenses, coherent lensless imaging techniques were originally conceived for x-ray and electron imaging, where the quality of optics used to be poor. Nevertheless, this makes them particularly useful in THz imaging too, where the dramatic increase in wavelength would require optics so large as to make conventional imaging experiments more difficult and unpractical to implement. As a rule of thumb given in [34], the aperture of the optics should be at least twice that of the incoming beam size in order to avoid diffraction effects.

In this contribution, THz coherent lensless imaging techniques will be reviewed, with a two-fold relevance. First, its content will complement the two latest reviews of THz imaging [12,13], mostly focusing on THz-TDS imaging, near-field imaging, tomography, and compressive sensing. Second, we have realized that the peculiar interaction of THz radiation with materials triggered the development of new THz coherent lensless imaging techniques, which can in turn be implemented at different wavelengths [35,36]. This review is therefore meant to build a bridge between the THz and imaging communities, both of which are expected to benefit from it.

The paper summarizes both the technical and theoretical aspects of THz coherent lensless imaging. Section 2 reviews the coherent THz sources and detectors used to perform them, and lists the source–detector combinations that yielded successful THz imaging setups. Section 3 explains the operational principles of digital holographic and phase retrieval techniques and reports on their implementation with THz radiation. Finally, a summary and outlook are provided in Section 4.

2. COHERENT THz SOURCES AND DETECTORS

A. Overview

The generation and detection of THz radiation remain the most challenging yet revolutionary domains (see, e.g., [1,13,3740]). In particular, coherent THz sources and intensity-sensitive detectors are the core elements employed in THz coherent imaging systems. This section discusses the representative THz sources and detectors with emphasis on their applicability in THz coherent lensless imaging systems.

B. Coherent THz Sources

The mechanisms for coherent THz generation are based on various physical principles [1]. As the THz range is located between microwaves and infrared radiation, it is no surprise that THz radiation can be generated by both optical and electronic techniques. In the following, we discuss the THz sources by their generation principle, from pure optical to pure electronic.

Gas lasers pumped by a $ {\text{CO}_{2}} $ laser are a high-power table-top source of continuous-wave (CW) THz radiation. They are based on stimulated emission from rotational transitions in molecules such as methanol, formic acid, and their deuterated compounds and offer a wide selection of single-line emissions from around 60 µm to 500 µm with powers up to several tens of mW [41]; CW radiation at 2.52 THz (118.8 µm) can exceed 150 mW [42]. The single-line operation with a coherence length of several meters and the power level make them a convenient source for coherent imaging (see Section 2.4).

Difference frequency generation (DFG) provides a tunable THz source by mixing two lasers in a non-linear medium [4345] and operates at room temperature. Because of the non-linear optical principle, DFG is preferably based on pulsed lasers. In optical rectification second-order non-linearity is used to generate a difference frequency in the THz domain. Here, the use of pulsed lasers limits the coherence length to typically below a few mm [46]. In four-wave mixing, third-order non-linearity is used from non-linear crystals [47], but also from water vapor or laser-induced air plasma [48]. THz sources based on DFG have not been used so far for coherent imaging. For CW photomixing, powers of a few 10 µW and a coherence length of 13 m were reported [44], limited by the coherence length of the pump lasers. As the optical path rather than a CW phase is measured, pulsed sources are applicable for coherent imaging only when used in scanning mode.

Photoconductive antennas are used to generate a burst of THz radiation. These combined electronic–optical devices use photoinduced currents from micro-antennas [49] or photo-mixing of two lasers/laser modes in a semiconductor coupled to microstructured antennas [50], generating a ps THz pulse corresponding to a pulse length of 300 µm or to a spectral band spanning typically 0.1 THz to 7 THz. To obtain phase information, a synchronized gated detection device is used.

Quantum cascade Lasers (QCLs) are electrically pumped unipolar lasers based on electronic transitions from semiconductor multilayered structures [5153]. QCLs are attractive for coherent imaging, because they are table-top and approach powers of a fraction of a W [54]. Although Stirling, liquid nitrogen, or cryogenic cooling would increase the output power [55,56], progress is being made towards room-temperature high-power sources [57,58]. There exist single-line and multi-line devices operating in pulsed mode, providing a CW equivalent THz power of several mW [59]. The coherence length of a single-line QCL is typically several meters [60] and can reach several hundred meters with external stabilization [61].

${p}$-type Ge-lasers [62] are tunable CW THz sources, but need cryogenic cooling to helium temperature and are not practical for coherent THz imaging.

Electronic solid-state oscillators are also based on semiconductor technologies [63]. Impact ionization avalanche transit-time (IMPATT) diodes and Gunn diodes are compact sources in this category. A microwave oscillator is created by applying a DC voltage to bias the device into its negative resistance region. Gunn diodes based on gallium arsenide are made for frequencies up to 200 GHz, while those relying on gallium nitride can reach up to 3 THz [64,65]. As these devices operate at room temperature in CW mode emitting monochromatic radiation in the range of 0.1–1 THz (from here on referred to as “sub-THz radiation”), they are suitable sources for coherent imaging.

Frequency multiplier chains are often used with electronic sources such as Gunn and IMPATT diodes to generate even higher frequency radiation. Frequency multipliers are Schottky-diode-based or transistor-based electronic circuits, which have a nonlinear response to electromagnetic waves [65]. They generate higher harmonic components of the incoming wave. With a suitable filter or waveguide, harmonics are collected. It is also possible to use several frequency multipliers in series to produce even higher frequencies. Frequency multiplier modules are often integrated in the transmitter and receiver parts of a millimeter wave vector network analyzer (VNA) as a frequency extender.

Backward wave oscillators (BWOs) are vacuum tubes used to generate microwaves up to the THz range. Belonging to the traveling-wave tube family, they are oscillators tunable over a wide range of frequencies by varying the accelerating voltage [66,67]. The output power in the range of 1 mW at 1 THz to 50 mW at 0.2 THz is coupled out near the electron gun. Despite lower power at high frequencies, a combination of millimeter-wave BWO (100–370 GHz) with frequency multipliers offers a very attractive alternative to sub-mm wave BWO, extending their spectral coverage to 2.2 THz [68]. High output powers, narrow spectral linewidths, and frequency tunability are the main advantages of these THz sources. Due to the good quality wavefront they produce, they find use as illuminators in coherent THz imaging [69].

THz sources based on free electron lasers (FELs) are emerging. In an early work investigating the possibility of THz 3D holographic tomography, a coherence length of 1 cm for the THz pulse was reported [70]. The FEL output pulse is typically near-Fourier-transform limited. A discussion of high-power THz sources based on vacuum electronics, including BWO and FEL, is found in [71].

C. THz Detectors

Imaging with array detectors working up to video frame rates allows dynamic measurements and is today the method of choice for THz coherent lensless imaging. The first approaches to THz hologram recording using array detectors were discussed already in 2005 [7274]. One of them uses indirect thermal methods to record the temperature increase of a plate induced by absorption of THz radiation. This is based on thermography cameras or on thermally sensitive phosphor plates, which are read out with a CCD camera [75]. Triggered by a first study conducted at the U.S. Naval Research Lab (NRL) [14], uncooled micro-bolometer arrays for thermal imaging started to be used in the THz range [7678]. A comprehensive and quite recent compilation of available THz detectors is given in the review paper by Dhillon et al. [1].

In the following, we summarize the properties of different detector types that have been utilized in lensless imaging.

Pyroelectric cameras are solid-state arrays able to detect radiation spanning from infrared to THz using $ {\text{LiTaO}_3} $ pyroelectric crystals as detector material. A chopper is integrated to modulate the irradiance in time. Pyrocam III and Pyrocam IV are commercially available pyroelectric cameras from Ophir [79]. Pyrocam III has a resolution of $ 124 \times 124 $ pixels with a pitch of 100 µm. The latest model Pyrocam IV has a higher resolution of $ 320 \times 320 $ pixels with a pitch of 80 µm.

Microbolometers are bolometer detectors integrated on a chip. They measure the power of electromagnetic radiation indirectly via the temperature-dependent electrical resistance of the detector material, typically amorphous silicon, vanadium oxide, or silicon nitride. Microbolometers designed for infrared applications represent an established technology field, with typical resolutions of ${640} \times {480}\,\,\text{pixels}$, even though arrays of up to ${1280} \times {960}\,\,\text{pixels}$ can be found [80]. For many practical applications, the scene imaged by the thermal detector is at room temperature, where the noise content of the image is dominated by the thermal radiation noise. The use of uncooled array detectors is generally sufficient, as thermal noise from such a camera is on the same order as that from the scene. Microbolometers have been intensively applied for long-wave infrared coherent imaging [81]. Interestingly, the microbolometers designed for the wavelength range 8–14 µm possess better sensitivities than THz microbolometers around 100 µm [82] and thus have become the cameras of choice for lensless imaging applications [35,36,8387]. Notice that, however, care should be taken because their pixels are venerable to dazzling or permanent damage caused by a low-power (several µW) laser focused on several pixels. For a review on the use of uncooled bolometer-type infrared detectors for real-time THz imaging, see also [88,89]. Microbolometers specifically designed for THz radiation include cameras from the National Optics Institute (INO, Québec, Canada) [90], the NEC Corporation (Tokyo, Japan) [91], and the French Alternative Energies and Atomic Energy Commission (CEA Leti) [92,93].

Detection of sub-THz radiation at room temperature is often realized with Schottky-barrier diodes (SBDs) or field effect transistors (FETs) [94,95]. The detection mechanism of SBDs and FETs is based on the rectification process of electromagnetic signals. At low radiation powers, the output voltage is proportional to the input power. Both SBDs and FETs show response times below 10 ps at room temperature, and can be assembled into arrays [96,97].

D. Source–Detector Systems

Sub-THz radiation is the probe of choice for the investigation of dielectrics such as clothes, building materials, 3D printing filaments, and composites, as their absorption coefficient increases drastically when the frequency exceeds 1 THz [3,98,99]. The long wavelength implies that a fairly large numerical aperture (NA) should be employed to achieve an appropriate lateral resolution. For instance, in [100], when working at 0.495 THz ($ \lambda = 606\,\,{\unicode{x00B5}\text{m}} $), for a sample located 16.3 cm away from the detector, a detection area of $ 20 \times 20\,\,\text{cm} $ is needed to achieve a lateral resolution comparable to the wavelength. To the authors’ knowledge, most published works on lensless imaging at sub-THz band have been done using a raster-scanned single detector, due to the lack of large enough 2D arrays with adequate sensitivity [9].

Materials such as polyethylene, polypropylene, polystyrene, poly tetrafluoroethylene (Teflon) [101,102], thin textiles [103], or dehydrated biological tissues [104] should be probed at frequencies above 1 THz, as they maintain high transparency, and images at better resolution can be obtained. The first reports on successful camera-based THz holography used the pyroelectric detector Pyrocam III [105,106]. In later works, models with higher resolutions were used [107]. Decent signal-to-noise ratios (SNRs) can be achieved with pyroelectric cameras at the strongest line (2.52 THz) of far-infrared gas lasers (FIRLs), after multi-frame averaging and dead pixel replacement procedures to improve the SNR [106,108,109]. However, the rather large sample pitch of 80–100 µm set a limit to the off-axis angle in off-axis digital holography. A comparison of four area detectors for their use in THz off-axis digital holography and real-time THz imaging was presented by Hack et al. [82]. According to them, the tested uncooled microbolometers are 40 times more sensitive than the pyroelectric camera Pyrocam III. As a consequence, the high detectivity of infrared microbolometers allows working with mW-level output sources such as QCLs or various FIRL lines [82,110113]. Their pixel pitch of 17–25 µm is ideal for off-line holography, as it allows large off-axis angles. Moreover, their frame rate can go up to 50 Hz, enabling real-time imaging [114].

Representative imaging configurations, using cameras or scanning single-pixel detectors, are summarized in Table 1. The imaging techniques of these works will be detailed in the next section.

Tables Icon

Table 1. Combinations of Sources and Detectors Used for THz Lensless Imaging

3. COHERENT LENSLESS IMAGING TECHNIQUES

A. General Remarks

Despite most coherent lensless imaging techniques using THz radiation bear no difference from the corresponding implementations at shorter wavelengths, e.g., with visible light, x rays, or electrons, the tremendous increase in wavelength has a relevant impact on the design and analysis of a THz imaging experiment.

From here on, we will describe the amplitude and phase modulation imposed by an unknown object, be it probed in transmission or in reflection, with a two-dimensional (2D) complex function on the plane of the object $ o(\textbf{x}) $, with $ \textbf{x} \equiv (x,y) $. Radiation at the wavelength $ \lambda $ normally impinging on the object is diffracted at angles $ {\gamma _{x,y}} $ with respect to the $ x,y $ axis given by $ \cos ({\gamma _{x,y}}) = \lambda {f_{x,y}} $ [129], where $ \textbf{f} \equiv ({f_x},{f_y}) $ is the spatial frequency coordinate corresponding to $ \textbf{x} $. While this makes the requirements on the dynamic range less stringent when using THz radiation, minimizing the object–detector distance becomes the most crucial issue in THz imaging. In practical cases, the camera housing sets a lower limit to the object–detector distance around $ d \approx 5\,\, \text{mm} $. A reasonable estimate of the incident beam size in all full-field, THz coherent lensless imaging techniques amounts to $ w \approx 5\,\, \text{mm} $, which translates to a Fresnel number $ {N_F} \equiv {w^2}/(\lambda d) = 50 $ at $ \lambda = 0.1\,\, \text{mm} $. Therefore, the far-field (or Fraunhofer) approximation, commonly employed in optical [130], x-ray [30], and electron [32] imaging, breaks down. In what follows, a generic complex wavefront $ g(\textbf{x}) $ (representing, e.g., the object function at the object plane) will be propagated to a parallel plane at a distance $ |L| $, thus yielding the propagated wavefront $ G(\textbf{x}) $ (representing, e.g., the wavefront diffracted by the object function at the detector plane), through the following convolution, indicated with the symbol $\ast$:

$$G(\textbf{x}) = g(\textbf{x}) \ast {h_L}(\textbf{x}) .$$
Here, $ {h_L}(\textbf{x}) $ is the Rayleigh–Sommerfeld convolution kernel [129], which has been obtained assuming only the scalar diffraction regime, and a propagation by $ |L| \gg \lambda $ through a homogeneous and isotropic medium. It is given by
$${h_L}(\textbf{x}) \equiv \frac{{|L|}}{{i\lambda }}\frac{{\exp [2\pi i \,\text{sgn}(L) \sqrt {|\textbf{x}{|^2} + {L^2}} /\lambda ]}}{{|\textbf{x}{|^2} + {L^2}}} ,$$
where $ L \gt ( \lt )0 $ denotes forward (backward) propagation, and $ \text{sgn}( \cdot ) $ is the sign function. The relatively high Fresnel numbers also make the angular spectrum propagation operator an alternative suitable choice in THz imaging [106].

B. Resolution in Coherent Lensless Imaging

Like all conventional imaging techniques, all the coherent lensless imaging techniques presented in this contribution are subject to the diffraction limit, i.e., the lateral resolution $ {\rho _{\text{lat}}} $ depends on the wavelength and the NA according to $ {\rho _{\text{lat}}} = \lambda /(2\,\,\text{NA}) $. In the absence of imaging components such as lenses, NA at a generic position $ \textbf{x} $ on the reconstructed wavefront is set only by the angle $ \eta $ subtended by the detector size from $ \textbf{x} $, so

$${\rho _{\text{lat}}} = \frac{\lambda }{{2\sin (\eta )}} ,$$
where a refractive index of 1 has also been assumed. Although the best achievable lateral resolution is limited by Abbe’s limit $ \lambda /2 $, much finer features can be resolved along the longitudinal direction. For example, in the reconstruction of an object with refractive index $ n $, measured in transmission at normal incidence, a phase difference of $ \Delta \phi $ between two points relates to a thickness difference $ \Delta t = \Delta \phi \lambda /[2\pi (n - 1)] $. In these conditions, it is the phase resolution $ {\rho _\phi } $ that determines the depth resolution $ {\rho _{\text{depth}}} $, as follows:
$${\rho _{\text{depth}}} = \frac{{{\rho _\phi }\lambda }}{{2\pi (n - 1)}} ,$$
which can lead to values of $ {\rho _{\text{depth}}} $ as low as about $ \lambda /91 $ [112].

In the following sections, the coherent lensless imaging techniques demonstrated using THz radiation will be discussed. For each technique, a theoretical overview as well as a summary of the published results will be provided.

C. Digital Holography

Holography reconstructs the object function $ o(\textbf{x}) $ by recording the intensity of the interference pattern between the wavefront diffracted by $ o(\textbf{x}) $ at the detector, referred to as “object beam” $ O(\textbf{x}) $, and a coherent wave that does not interact with the object and is referred to as “reference beam” $ R(\textbf{x}) $, yielding the following distribution known as a “hologram”:

$$I(\textbf{x}) \equiv |R(\textbf{x}) + {O(\textbf{x})|^2} .$$
Originally developed by Gabor in 1948 to replace conventional imaging techniques in electron microscopy [131], it is nowadays mostly performed with electromagnetic radiation. Owing to the recent increased computational capabilities of digital devices, the reconstruction has evolved from an analogue to a fully numerical procedure. Digital holography has therefore turned into the coherent lensless imaging technique of choice for many applications in biology, materials science, and mechanical engineering (see, e.g., [33,132135]).

1. Off-axis Digital Holography

In one variant of digital holography, named “off-axis” [Fig. 1(a)], the reference beam and the object beam travel along different directions. We denote their complex wavefront at the detector plane by $ U(\textbf{x}) \equiv {A_U}(\textbf{x})\exp \{ i[{\textbf{k}_U} \cdot \textbf{x} + {\phi _U}(\textbf{x})]\} $, where $ {A_U}(\textbf{x}) $ is the amplitude, $ {\phi _U}(\textbf{x}) $ is the phase when observed across a plane perpendicular to the average wavevector $ {\textbf{k}_U} $, and $ U \in \{ R,O\} $ labels the reference beam ($ R $) and the object beam ($ O $).

 figure: Fig. 1.

Fig. 1. Schematic of off-axis digital holography (simulations). (a) Experimental setup; (b) hologram and (c) modulus of its Fourier transform; (d) amplitude and (e) phase of the reconstructed object function. The inset of (a) shows the average wavevectors of the object beam and reference beam, as well as their difference. Wavelength: 96.5 µm. Scale bars in (b), (d), and (e): 2 mm; scale bar in (c): $ 5{\text{mm}^{ - 1}} $. Adapted with permission from [136].

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The hologram of Eq. (5) thus becomes

$$\begin{split}I(\textbf{x})& \equiv A_R^2(\textbf{x}) + A_O^2(\textbf{x}) + 2 {A_R}(\textbf{x}) {A_O}(\textbf{x}) \\ &\quad\times \cos [({\textbf{k}_R} - {\textbf{k}_O}) \cdot \textbf{x}+ {\phi _R}(\textbf{x}) - {\phi _O}(\textbf{x})] .\end{split}$$
The angle $ \theta $ between $ {\textbf{k}_R} $ and $ {\textbf{k}_O} $ [displayed in the inset of Fig. 1(a)] modulates $ I(\textbf{x}) $ [Fig. 1(b)] at the spatial carrier frequency $ {\textbf{f}_c} $, with modulus $ \sin (\theta )/\lambda $ and same direction as $ \Delta \textbf{k} \equiv {\textbf{k}_R} - {\textbf{k}_O} $ on the Fourier plane. The Fourier transform of $ I(\textbf{x}) $, $ {\cal I}(\textbf{f}) $ [whose modulus is shown in Fig. 1(c)], features a DC component at the spatial frequency $ \textbf{f} = (0,0) $, the $ +1 $st diffraction order $ {\cal C}(\textbf{f} - {\textbf{f}_c}) $ at $ \textbf{f} = {\textbf{f}_c} $, and the $ -1 $st diffraction order $ {{\cal C}^{\ast}}(\textbf{f} + {\textbf{f}_c}) $ at $ \textbf{f} = - {\textbf{f}_c} $, where $ {\cal C}(\textbf{f}) $ is the Fourier transform of $ c(\textbf{x}) \equiv {A_R}(\textbf{x}){A_O}(\textbf{x})\exp \{ i[{\phi _R}(\textbf{x}) - {\phi _O}(\textbf{x})]\} $. Following the widespread Fourier transform demodulation technique developed by Takeda et al. [137], provided that (i) $ {\textbf{f}_c} $ is large enough to prevent $ {\cal C}(\textbf{f} - {\textbf{f}_c}) $, $ {{\cal C}^{\ast}}(\textbf{f} + {\textbf{f}_c}) $, and $ {\cal A}(\textbf{f}) $ from overlapping; and (ii) the amplitude $ {A_R}(\textbf{x}) $ and phase $ {\phi _R}(\textbf{x}) $ of the reference beam are known or can be measured at a preliminary stage, then $ {A_O}(\textbf{x}) $ and $ {\phi _O}(\textbf{x}) $ are retrieved upon taking the modulus and the argument of $ c(\textbf{x}) $, respectively, after selecting $ {\cal C}(\textbf{f} - {\textbf{f}_c}) $ by filtering $ {\cal I}(\textbf{f}) $.

Since the detector plane is typically oriented perpendicularly to $ {\textbf{k}_O} $, the wavefront diffracted by the object can be simplified to $ O(\textbf{x}) = {A_O}(\textbf{x})\exp [i{\phi _O}(\textbf{x})] $. The reconstruction of $ o(\textbf{x}) $ is obtained by back-propagating $ O(\textbf{x}) $ by the object–detector distance $ d $ through the propagation kernel of Eq. (2):

$$o(\textbf{x}) = O(\textbf{x}) \ast {h_{ - d}}(\textbf{x}) .$$
If, like in the setup in Fig. 1(a), the object is tilted with respect to the detector plane, the reconstructed wavefront appears skewed [Figs. 1(d) and 1(e)]. A rotational transformation [138,139] may be finally applied to bring the reconstructions to the reference frame of the object.

Off-axis holography was the first variant of digital holography ever implemented with THz radiation, performed in transmission mode. Mahon et al. first demonstrated an off-axis THz digital holography configuration using a 100 GHz Gunn diode oscillator and a SBD installed on a planar scanner to record the hologram pixel by pixel [115,140]. A Teflon sample inside an envelope was reconstructed with a lateral resolution of 9 mm ($ 3\lambda $). In 2011, Heimbeck et al. proposed a THz off-axis digital holography geometry based on a Mach–Zehnder interferometer [119]. The off-axis holograms were recorded with a Schottky diode square law detector, combined with a lock-in amplifier and mounted on a 2D linear stage. Tuning the emission frequency in the range of 0.66–0.76 THz through a frequency-multiplied microwave synthesizer allowed the use of a dual-wavelength approach to eliminate the $ 2\pi $ phase ambiguity problem for optical path differences as large as the synthetic wavelength. Note that this well-known multi-wavelength technique has also been developed in other THz interferometry setups for, e.g., thickness measurement applications [141,142]. The first actual “full-field” implementation was provided by Ding et al. using a 2.52 THz optically pumped THz laser and a pyroelectric detector with $ 124 \times 124$ pixels and obtaining a lateral resolution of about 0.4 mm ($ 3.4\lambda $) [105]. By shortening the recording distance, Li et al. [122] pushed the resolution down to 0.245 mm ($ 2.1\lambda $). In 2014, Hack and Zolliker used a 3 THz non-monochromatic QCL and an uncooled microbolometer array detector to build an off-axis setup based on a Lloyd’s interferometer [83]. A metallic Siemens star and a patterned polypropylene slab were reconstructed with a lateral resolution of 0.280 mm ($ \approx 2.8\lambda $) and a phase resolution of 0.5 rad, corresponding to a depth resolution of 16 µm according to Eq. (4). Shortly afterwards, Yamagiwa et al. reported reconstructions of optically opaque plastic and silicon plates with a depth resolution of 1.1 µm ($ \lambda /91 $) [112].

An off-axis digital holographic setup conveniently lends itself to reconstructions in reflection mode, too. The first implementation with THz radiation was reported by Cherkassky et al. [73]. Quasi-CW THz radiation was generated by a Novosibirsk high-power FEL in the wavelength range of 120–180 µm. Holograms were indirectly recorded via a combination of digital video camera and InAs near-infrared thermograph. In 2008, Tamminen et al. proposed a THz off-axis digital holographic setup for reflective objects placed 1.5 m away from the detector, reaching resolutions between 4 mm and 8 mm ($ 4 - 8\lambda $) [118].

Later on, Zolliker and Hack proposed a THz off-axis digital holography setup in reflection, where resolution enhancement was achieved via a synthetic aperture acquisition [84] borrowed from the radar imaging community [143]. The system included a movable mirror to produce phase-shifted holograms, and the detector was moved across its detection plane so as to synthesize a hologram with an area 3.5 times larger than the detector area, after stitching 19 partially overlapping holograms. The obtained lateral and depth resolutions were 200 µm ($ \approx 1.7\lambda $) and 6 µm ($ \approx \lambda /20 $), respectively. Locatelli et al. successfully reconstructed in real time a moving metallic plate [Fig. 2(a)], both when it was directly seen by the detector [Fig. 2(b)] and when it was hidden behind an optically opaque polypropylene mask [Figs. 2(c) and 2(d)] [85]. With a similar setup, Valzania et al. proposed a systematic procedure to suppress the spurious reflections from a cover plate hiding an object from the camera field of view, thereby improving the reconstruction of the hidden object [35]. Humphreys et al. reported the first video rate (50 Hz) THz off-axis digital holography reconstructions, achieving a resolution of 280 µm ($ 2.4\lambda $) [114]. Recently, Wang et al. used a widespread sub-pixel image registration algorithm [144] and image stitching to expand the reconstructed field of view [126]. After a comparison with reference measurements with a surface profiler, they estimated a relative error of 3% and 6% in the reconstruction of a gold plated bookmark when it was not covered and covered by a Teflon plate, respectively.

 figure: Fig. 2.

Fig. 2. THz off-axis digital holographic reconstructions in reflection mode of an object moving at 5 mm/s. (a) Photograph of the object, a metallic plate with inscriptions; (b) reconstructed amplitude of the object at one position during its movement; (c) photograph of the plate covered by an optically opaque mask; (d) reconstructed amplitude of the hidden object at the same position as in (b). Scale bars: 4 mm. Adapted from [85] under the terms of the Creative Commons Attribution 4.0 License.

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2. In-line Digital Holography

In in-line digital holography, which is the variant originally conceived by Gabor, the reference beam and the object beam travel along the same direction before impinging on the detector. To allow such a scheme, the object must be smaller than the incident beam, or it should impose a weak modulation, such that a portion of the incident beam is not affected by the object and can act as a reference beam, interfering with the part of the beam being diffracted and playing the role of the object beam [Fig. 3(a)]. Figure 3 illustrates the principle using the simulated pure phase object displayed in Fig. 3(b) and the hologram in Fig. 3(c).

 figure: Fig. 3.

Fig. 3. Schematic of in-line digital holography (simulations). (a) Experimental setup; (b) simulated phase object and (c) corresponding hologram; (d) reconstruction where the (d) real [(e) twin] image is brought to focus. In (e), the complex conjugate of the reconstruction is shown, to favor its comparison with (d). Wavelength: 96.5 µm. Scale bars: 2 mm.

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Using the superscript * to denote complex conjugation, we rewrite Eq. (5) as

$$I(\textbf{x}) = |R(\textbf{x}{)|^2} + |O(\textbf{x}{)|^2} + {O^{\ast}}(\textbf{x})R(\textbf{x}) + {R^{\ast}}(\textbf{x})O(\textbf{x}) .$$
Illuminating the hologram with the reference beam another time yields the following distribution:
$$\begin{split}{R(\textbf{x})I(\textbf{x})} &= R(\textbf{x})|R(\textbf{x}{{)|}^2} + R(\textbf{x})|O(\textbf{x}{{)|}^2} \\&\quad + {O^{\ast}}(\textbf{x}){R^2}(\textbf{x})+ |R(\textbf{x}{{)|}^2}O(\textbf{x})\\& \approx {O^{\ast}}(\textbf{x}) + O(\textbf{x}) ,\end{split}$$
where the approximation holds under the assumptions that $ |O(\textbf{x})| \ll |R(\textbf{x})| $, the reference beam is a plane wave normally impinging on the detector, i.e., $ R(\textbf{x}) = \text{constant} $, and the constant background and factors have been omitted. A back-propagation of such a distribution by the object–detector distance $ d $, using the fact that, apart from a constant phase factor, $ h_L^{\ast}(\textbf{x}) = {h_{ - L}}(\textbf{x}) $ [see Eq. (2)], leads to the distribution
$$[R(\textbf{x})I(\textbf{x})] \ast {h_{ - d}}(\textbf{x}) \approx {o^{\ast}}(\textbf{x}) \ast {h_{ - 2d}}(\textbf{x}) + o(\textbf{x}) ,$$
whose phase is shown in Fig. 3(d), featuring the reconstructed object $ o(\textbf{x}) $ superimposed with an out-of-focus image of $ {o^{\ast}}(\textbf{x}) $, referred to as “twin image.” Conversely, forward propagating the last side of Eq. (9) by $ d $ brings the twin image $ {o^{\ast}}(\textbf{x}) $ in focus and the real image $ o(\textbf{x}) $ out of focus [see Fig. 3(e), where the complex conjugate of the twin image is shown, which is equivalent to the real image]. The overlap of these two distributions worsens the reconstruction of $ o(\textbf{x}) $, and solutions have been suggested to cope with the twin image problem, employing mostly iterative phase retrieval procedures that will be detailed in the next section (see, e.g., [145147]).

Compared with the off-axis variant, in-line digital holography represents a more compact solution featuring a shorter reconstruction distance and consequently a higher resolution, although it is suited only for isolated or almost transparent objects. Xue et al. performed CW THz in-line digital holography [148], increasing the lateral resolution by a factor of two compared to [105] ($ 1.7\lambda $ as opposed to $ 3.4\lambda $), and demonstrated its effectiveness in imaging hidden objects [122]. Hu et al. thoroughly investigated different amplitude, phase, and support constraints on the object plane as well as zero padding of holograms, boundary replication expansion, and apodization to improve the iterative phase retrieval in THz in-line digital holography [123,124]. Upon recording two sets of in-line holograms at different distances [149], Li et al. departed from the conventional in-line digital holographic reconstruction procedure, gradually blurring the boundary between in-line digital holography and phase retrieval. Further, they recorded holograms translated by sub-pixel distances to yield a finer hologram sampling, and they overall achieved a lateral resolution of $ 1.3\lambda $. Rong et al. combined the phase retrieval algorithm from [145] with a hologram extrapolation method [150] to suppress the twin image and enhance the lateral resolution of a dragonfly hindwing, revealing features of 35 µm ($ \approx \lambda /3 $) [106]. While hologram extrapolation has the advantage of being a post-processing tool, which does not impact the acquisition time of the experiment, it can provide only a guessed solution in the regions that were not measured. As an alternative, a synthetic aperture scheme uses real holograms to increase the resolution, and is an effective solution for THz in-line digital holography, as well. Examples were reported in [110,111], reconstructing features as low as $ \lambda $. In Ref. [108], THz in-line digital holography was implemented toward a medical application. The reconstruction of a hepatocellular carcinoma tissue slice [Fig. 4(a)] proved that early signs of liver cancer and diseases can be traced to the phase of a reconstructed THz hologram. Although the reconstructions from one hologram [Figs. 4(b) and 4(c)] did not provide enough insight, increasing the resolution through synthetic aperture acquisition [Figs. 4(d) and 4(e)] and in combination with numerical hologram extrapolation [Figs. 4(f) and 4(g)] revealed a sign of tissue fibrosis, thus making THz coherent lensless imaging a promising tool for cancer diagnosis, with the potential to complement conventional histopathological analyses.

 figure: Fig. 4.

Fig. 4. THz in-line digital holographic reconstructions. (a) Photograph of the object, a human hepatocellular carcinoma tissue; (b) reconstructed absorption and (c) phase shift from a single $ 12.4 \times 12.4\,\,{\text{mm}^2} $ hologram; (d) reconstructed absorption and (e) phase shift from a larger hologram obtained through aperture synthesis; (f) reconstructed absorption and (g) phase shift after numerically extrapolating the holograms used for reconstructions (d) and (e). The green arrow indicates a cut across a vessel or a region damaged after freezing the object. The blue arrow indicates a vertical line that is a sign of tissue fibrosis, which can be resolved only in (g). Adapted from [108] under the terms of the Creative Commons Attribution 4.0 License.

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Recently, Li et al. reported a resolution of $ 0.7\lambda $ adding a $ {L_1} $-sparsity constraint to the support constraint at the object plane [87]. Further strategies for the correction of experimental inaccuracies were reported. Chen et al. developed a denoising method for THz in-line digital holographic reconstructions, based on a Markov chain Monte Carlo sampling [151]. Different auto-focusing algorithms and corrections were investigated by Huang et al. [125,127] and applied to reconstruct a pair of objects at different distances from the detector [121].

D. Phase Retrieval

Phase retrieval imaging techniques aim at reconstructing the object function $ o(\textbf{x}) $ from the intensity of its diffraction pattern $ {I_j}(\textbf{x}) $ measured at one or multiple distances $ {d_j} $, $ j = 1,2,\ldots,J $, as shown at the top of Fig. 5, i.e.,

$${I_j}(\textbf{x}) = |o(\textbf{x}) \ast {h_{{d_j}}}(\textbf{x}{)|^2} .$$

 figure: Fig. 5.

Fig. 5. Steps of a typical phase retrieval technique, using three diffraction patterns recorded at different distances from the object (simulations). Wavelength: 96.5 µm. Scale bars: 2 mm.

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Although the acquisition setup recalls that of in-line digital holography, if we assume $ J = 1 $ (Fig. 3), the reconstruction procedure is essentially different from the one outlined in Section 3.3.2, the main difference being that phase retrieval techniques need not model a reference beam. This makes the experimental constraints easier to meet, as the object is allowed to be strongly diffracting and even have a size comparable to that of the incident beam.

We assume that each $ {I_j}(\textbf{x}) $ is sampled with $ N \times N = {N^2} $ pixels, and that $ o(\textbf{x}) $ is unknown on a number of pixels $ {M^2} \le {N^2} $. Because both the amplitude and the phase of $ o(\textbf{x}) $ have to be determined, the total number of unknowns amounts to $ 2{M^2} $. Using the definition of oversampling ratio given by Miao et al. [152],

$$\sigma \equiv \frac{{\text{total number of pixels}}}{{\text{number of pixels of unknown value}}} = \frac{{{N^2}}}{{{M^2}}} ,$$
we can therefore conclude that an oversampling ratio $ \sigma = 2 $ is needed in order to invert the system of Eq. (11). In real experiments, however, the presence of noise requires redundant information, so typically $ \sigma \gg 2 $ is preferred. Each phase retrieval technique aims at increasing the oversampling ratio in at least one of the following ways:
  • • by increasing the total number of pixels $ {N^2} $, collecting several ($ J \gt 1 $) diffraction patterns described by Eq. (11) at different distances from the object [153,154];
  • • by decreasing the number of pixels of unknown value $ {M^2} $, using a priori knowledge on the object function at some locations [31]. Because usually the approximate spatial extent of the object or of the incident beam is known, such a priori information is referred to as “support constraint.”

Therefore, a typical iterative phase retrieval procedure proceeds according to these steps, graphically summarized in Fig. 5:

  • 1. Construct a first estimate of $ o(\textbf{x}) $, usually by assigning a constant or random distribution to its amplitude and phase (left-hand side of Fig. 5). If available, a support constraint, represented with a red circle in Fig. 5, is applied.
  • 2. Propagate the current estimate of $ o(\textbf{x}) $ to the first detector plane through the propagation kernel of Eq. (2). Apply the so-called “intensity constraint,” replacing the calculated amplitude of the propagated wavefront with the square root of the measured intensity at that detector plane, while keeping the phase unchanged.
  • 3. Propagate the corrected wavefront to the next detector plane, if any, and apply the intensity constraint again using the diffraction pattern recorded at the corresponding plane. Repeat this operation for every remaining detector plane (Fig. 5 shows the process for $ J = 3 $).
  • 4. Back-propagate the last corrected wavefront to the object plane, where the support constraint is applied again.
  • 5. Iterate steps 2–4, enclosed in the orange box in Fig. 5, until a suitably defined error function becomes lower than a predefined threshold.

1. Two-intensity Techniques

Using the diffraction patterns recorded at two detector planes, which increases the oversampling ratio by a factor of two, may not be enough for a phase retrieval algorithm to converge to the sought solution [155]. In this case, to further increase the oversampling ratio and lower the chance that the algorithm stagnates in a local minimum, $ {M^2} $ is decreased to values much lower than $ {N^2} $ through a support constraint.

A phase retrieval technique of this kind was performed by Hislop et al. using THz radiation [120]. The THz source was a BWO operating at 0.58 THz and the detector was a Schottky diode, sensitive only to the power of the incident THz radiation and scanned across two $ 50 \times 50\,\,{\text{mm}^2} $ planes, with a relative distance of about $ \lambda $, i.e., 0.5 mm [Fig. 6(a)]. Their reconstruction technique, referred to as the “successive projections method” [155], reproduced a standard iterative phase retrieval procedure like the one outlined in the previous section, where the knowledge of the incident beam was used as a support constraint. Two additional constraints were applied to favor convergence. The first one consisted of updating the low spatial frequencies of the object function during the first iterations, and subsequently allowing the reconstruction to be refined at higher and higher spatial frequencies. Notice that such a constraint is essentially another way to reduce the number of pixels with unknown value $ M $ [see Eq. (12)] in the first iterations, thereby increasing the oversampling ratio. The second constraint represented a modified version of the intensity constraint, where the calculated diffracted amplitude at the $ j $th detector plane $ {A_j}(\textbf{x}) $ was averaged with the square root of the corresponding measured intensity $ \sqrt{{I_j}(\textbf{x})} $, yielding the corrected estimate of the wavefront at the $j$th detector plane $A_j^\prime($, as follows:

$$A_j^\prime(\textbf{x}) \equiv (1 - \beta ){A_j}(\textbf{x}) + \beta \sqrt {{I_j}(\textbf{x})} .$$

 figure: Fig. 6.

Fig. 6. Two-intensity phase retrieval. (a) Schematic experimental setup, featuring: a BWO (A) with its waveguide opening (B), a chopper (C), a beam splitter made of non-conducting silicon (D), a detector to monitor the stability of the source (E), a beam stopper to prevent the THz radiation emitted by the source from directly reaching the receiver (F), mirrors (G), (H), a metallic thumbtack used as the object (I), and the receiver (J) moved longitudinally through two sliding blocks (K), (L) and transversely through a 2D stage (M). (b) Amplitude of the reconstructed object and (c) phase of the object and of the incident beam. Adapted with permission from [120] 2019 IEEE.

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The real parameter $ \beta $, known as the “over projecting factor,” decreases its value from $ \approx 3 $ to 1 with increasing iterations and helps the algorithm reach the global minimum of the error function, avoiding stagnation in local minima. When approaching the last iterations, i.e., $ \beta = 1 $, Eq. (13) reduces to the standard intensity constraint $ A_j^\prime(\textbf{x}) \equiv \sqrt {{I_j}(\textbf{x})} $. The performance of the algorithm was demonstrated by successfully reconstructing a metallic thumbtack in transmission mode [Figs. 6(b) and 6(c)].

2. Multiple-intensity Techniques

As opposed to two-intensity phase retrieval techniques, multiple-intensity methods employ diffraction patterns collected at $ J \gt 2 $ planes in order to increase the oversampling ratio to values greater than 2, obviating the need for a support constraint.

The single-beam multiple-intensity reconstruction (SBMIR) technique [154,156] follows the typical five steps of phase retrieval techniques to reconstruct $ o(\textbf{x}) $ with no a priori knowledge on it.

The optimum acquisition parameters of a SBMIR experiment have been discussed in [156158] and in the supplementary document of [36]. The minimum object–detector distance theoretically allowed must guarantee that the highest spatial frequencies of the wavefront diffracted by the object at the detector plane are sampled by the detector pixels without alising. This implies that $ \sin (\zeta /2) \lt \lambda /(4p) $, where $ \zeta $ is the angle under which a point on the detector centered with the object sees the object, and $ p $ is the pixel pitch. Since at THz wavelengths, $ \lambda \approx 100\,\,\unicode{x00B5}\text{m} $, and for currently available digital cameras, $ p \approx 20\,\,\unicode{x00B5}\text{m} $, $ \lambda /(4p) \gt 1 $, i.e., there are no restrictions (or no stringent restrictions in case longer wavelengths are used) on the minimum object–detector distance, with a positive impact on the NA and consequently on the lateral resolution.

The distance between consecutive detector planes should ensure that each new diffraction pattern provides both redundant and additional information to allow the phase to be iteratively retrieved. A reasonable estimate of the propagation length after which a diffraction pattern at the object–detector distance $ d $ has changed is the depth of focus DOF, scaling with the size $ w $ of the illuminated region according to [129]

$${\rm{DOF}} \approx \lambda {\left(\frac{d}{w}\right)^2} .$$
For example, imaging a field of view of $ w = 5\,\,\text{mm} $ at the wavelength $ \lambda = 0.1\,\,\text{mm} $ and at a distance $ d = 10\,\,\text{mm} $ yields $ {\rm{DOF}} = 0.4\,\,\text{mm} $.

Once the minimum object–detector distance as well as the distance between consecutive detector planes is fixed, the number of diffraction patterns should be chosen by carefully considering that the larger the object–detector distance, the lower the resolution of the diffraction pattern due to a lower NA, and the higher the chance that it will be corrupted by noise caused by, e.g., experimental misalignments and laser power loss through absorption during the propagation, resulting in a detrimental effect on the reconstruction. Although the optimum acquisition parameters vary with the object to be reconstructed, we have found that in all the implementations using THz radiation, up to five diffraction patterns have been used at a DOF ranging from 0.5 to 1 mm and at a minimum object–detector distance larger than $ \approx 5\,\,\text{mm} $ [36,120].

An example of THz SBMIR reconstructions will be discussed in the next section, as part of a phase retrieval technique for imaging behind a moving and scattering barrier.

3. Phase Retrieval Technique for Imaging behind a Moving and Scattering Barrier

Recently, an imaging technique reconstructing two objects stacked one behind the other in transmission mode has been developed and experimentally demonstrated with THz radiation [36].

A schematic setup is shown in Fig. 7(a). We denote the transmission functions of the two objects with $ b(\textbf{x}) $ and $ o(\textbf{x}) $, where “b” stands for the barrier and “o” for the object hidden behind it at a distance $ u $. When a plane wave with unit amplitude impinges on the hidden object, the wavefront $ \Psi (\textbf{x}) $ at a plane perpendicular to the optical axis and at the distance $ d $ from the barrier can be written as

$$\Psi (\textbf{x}) = \{ [o(\textbf{x}) \ast {h_u}(\textbf{x})]b(\textbf{x})\} \ast {h_d}(\textbf{x}) ,$$
where we have assumed the two objects are thin enough, such that their interaction with the corresponding incident wavefront can be described through the multiplicative approximation [32]. Nevertheless, we point out that no assumptions on $ b(\textbf{x}) $ and $ o(\textbf{x}) $ have been made, therefore allowing either object to strongly diffract its corresponding incident beam.

 figure: Fig. 7.

Fig. 7. Phase retrieval imaging behind a moving and scattering barrier. (a) Schematic experimental setup; (b) reconstruction of the wavefronts at the exit of the barrier plane through the SBMIR method; (c) reconstruction of the hidden object and the barrier (top row) assuming that the transversal shifts of the barrier are known a priori, (middle row) retrieving the shifts via cross-correlation, and (bottom row) assuming unknown shifts, which allows the reconstruction of the hidden object only. Scale bars: 2 mm. Adapted with permission from [159] The Optical Society.

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Provided that one object is transversely shifted with respect to the other one, and the shifts are known, both transmission functions $ o(\textbf{x}) $ and $ b(\textbf{x}) $ can be retrieved, with no a priori information on them. Denoting the translations of the barrier with $ {\textbf{x}_k} $, $ k = 1,2,\ldots,K $, Eq. (15) becomes

$${\Psi _k}(\textbf{x}) = \{ [o(\textbf{x}) \ast {h_u}(\textbf{x})]b(\textbf{x} - {\textbf{x}_k})\} \ast {h_d}(\textbf{x}) .$$
Now the reconstruction procedure relies on two steps:
  • 1. Retrieve the wavefronts $ {\psi _k}(\textbf{x}) $, referred to as “exit waves,” at the exit of the barrier plane, namely, the quantities
    $${\psi _k}(\textbf{x}) \equiv [o(\textbf{x}) \ast {h_u}(\textbf{x})]b(\textbf{x} - {\textbf{x}_k}) .$$
    This is achieved through the SBMIR technique from Section 3.D.2, using the intensities of a set of $ J $ diffraction patterns $ {\Psi _{kj}}(\textbf{x}) $ recorded at the distances $ {d_j} $, $ j = 1,2,\ldots,J $ from the barrier, for each position of the barrier with respect to the hidden object [Fig. 7(b)], as follows:
    $$|{\Psi _{kj}}(\textbf{x}{)|^2} \equiv |{\psi _k}(\textbf{x}) \ast {h_{{d_j}}}(\textbf{x}{)|^2} .$$
  • 2. Recover the transmission functions $ o(\textbf{x}) $ and $ b(\textbf{x}) $, using the exit waves available from the previous step, and the transversal shifts $ {\textbf{x}_k} $.

Towards this goal, we notice that, despite the barrier being seen directly by the detector, its reconstruction is prevented because it is illuminated by a set of strongly non-uniform probes, represented by the wavefronts transmitted through the hidden object and shifted by the amounts $ {\textbf{x}_k} $. In order to enable a reliable reconstruction of $ b(\textbf{x}) $, the authors proposed to wash out the high-frequency components of $ o(\textbf{x}) \ast {h_u}(\textbf{x}) $, so as to mimic a slowly varying probe incident onto the barrier. They achieved this by (i) compensating for the shift of the exit waves and (ii) averaging them. If we let $ {\cal S}_{k = 1}^K [{f_k}(\textbf{x})] $ denote an operator performing these two operations on each amplitude or phase distribution $ {f_k}(\textbf{x}) $ (see also the supplementary document of [36]), the estimated amplitude $ |b(\textbf{x})| $ and phase $ {\phi _b}(\textbf{x}) $ of $ b(\textbf{x}) $ read

$$|b(\textbf{x})| \approx {\cal S}_{k = 1}^K [|{\psi _k}(\textbf{x})|],$$
$${\phi _b}(\textbf{x}) \approx {\cal S}_{k = 1}^K [{\phi _{{\psi _k}}}(\textbf{x})] .$$
Finally, the hidden object is obtained by dividing each exit wave by the barrier transmission function, and back-propagating the wavefront to the object plane:
$$o(\textbf{x}) = {\left\langle {\frac{{{\psi _k}(\textbf{x})}}{{b(\textbf{x} - {\textbf{x}_k})}}} \right\rangle _k} \ast {h_{ - u}}(\textbf{x}) ,$$
where $ {\langle \cdot \rangle _k} $ performs the average over all the configurations indexed by $ k $.

The method was experimentally verified using THz radiation to reconstruct a glass fabric sample and a pure amplitude or a pure phase object hidden behind it. Upon translating the fabric across a 2D square grid of ${20} \times {20} = {400}\,\,\text{points}$ with a spacing of $ \approx 0.8\lambda $, the authors could reconstruct the hidden objects with a depth resolution of $ \approx \lambda /10 $ and a lateral resolution of $ \approx 1.5\lambda $ [see the top row of Fig. 7(c), showing the reconstructions for an amplitude object]. Furthermore, they demonstrated comparable results after retrieving the shifts $ {\textbf{x}_k} $ through cross-correlation on the measured diffraction patterns [middle row of Fig. 7(c)]. Most interestingly, they showed that reconstructing the hidden object is possible even when the shifts are unknown, or cannot be retrieved through cross-correlation [bottom row of Fig. 7(c)], thus suggesting promising applications for imaging behind dynamic scattering media.

4. Ptychography

Another coherent lensless imaging technique successfully implemented with THz radiation is ptychography [32]. Hoppe originally conceived the ptychographic method in 1969 as a new microscopic principle for imaging crystalline samples [160] and, like holography, in order to improve electron imaging, which suffered from poor imaging optics. In its simplest and most common implementation, ptychography iteratively reconstructs an object using a set of diffraction patterns, obtained upon scanning the object with a coherent beam with partially overlapping neighboring positions. The combination of the original ptychographic idea with iterative phase retrieval algorithms, suggested by Rodenburg and Faulkner [32,161], boosted the interest of the imaging community in ptychography. Several algorithms have been put forward, e.g., reconstructing the incident beam alongside the object [162164], dealing with partially coherent radiation [165], or recovering the scan shifts between the beam and the object [166]. Ptychography has been heavily used with x rays [167], as well as with visible [164] and ultra-violet [168] light and, only recently, it has been demonstrated with THz radiation too [86]. In the next section, the principles of a basic ptychographic algorithm, known as ptychographic iterative engine (PIE) [161], will be outlined.

 figure: Fig. 8.

Fig. 8. Schematic of ptychography (simulations). (a) Experimental setup. (b) Amplitude and (c) phase of the object transmission function reconstructed from only the top-left diffraction pattern. (d) , (f) Amplitude and (e) , (g) phase of the object transmission function after 1 [100] iteration[s]. Wavelength: 96.5 µm. The white scale bar in the top-right panel holds for all the diffraction patterns, while the reconstructions share the same black scale bar in (d). All the scale bars equal 2 mm. Adapted with permission from [136].

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PIE algorithm: Fig. 8(a) sketches the geometry of a typical ptychographic experiment. We let an aperture crop a coherent beam, referred to as “probe” and represented by the 2D distribution $ p(\textbf{x}) $, which impinges on the object with transmission function $ o(\textbf{x}) $. A collection of diffraction patterns $ {I_k}(\textbf{x}) $, $ k = 1, \ldots ,K $, is acquired while shifting the object with respect to the probe by the amounts $ {\textbf{x}_k} $, such that the regions of the sample illuminated at consecutive positions of the beam partially overlap (typical values of overlap range between 60% and 80% [169]). This over-determination of information allows the reconstruction of $ o(\textbf{x}) $ in an iterative fashion.

Provided that the object satisfies the thin object approximation, further discussed in [32,162,170] and also used in the phase retrieval technique described in Section 3.D.3, the wavefront right at the exit of the object plane, referred to as “exit wave” $ {\psi _k}(\textbf{x}) $, can be modeled as the product

$${\psi _k}(\textbf{x}) = p(\textbf{x}) {o_k}(\textbf{x} - {\textbf{x}_k}) ,$$
where the subscript $ k $ is used to indicate the $ k $th estimates of the exit wave and the object function. As a rule of thumb, a thickness of up to a few $ \lambda $ guarantees that the thin object approximation is satisfied well enough to yield a resolution comparable to $ \lambda $. The first step of the PIE algorithm consists of creating an estimate of the exit wave at the detector plane, $ {\Psi _k}(\textbf{x}) $, through a numerical propagation of $ {\psi _k}(\textbf{x}) $ by the object–detector distance $ d $:
$${\Psi _k}(\textbf{x}) = {\psi _k}(\textbf{x}) \ast {h_d}(\textbf{x}) .$$
Because the amplitude of the wavefront at the detector plane should match the square root of the measured diffraction pattern $ {I_k}(\textbf{x}) $, the “intensity constraint” typical of phase retrieval is applied, yielding the corrected wavefront at the detector plane $\Psi_k^\prime(\textbf{x}) $ [Eq. (24)] and, after a numerical back-propagation, at the object plane $ \psi_k^\prime (\textbf{x}) $ [Eq. (24)]:
$$\Psi_k^\prime(\textbf{x})= \sqrt {{I_k}(\textbf{x})} \frac{{{\Psi _k}(\textbf{x})}}{{|{\Psi _k}(\textbf{x})|}} ;$$
$$\psi_k^\prime(\textbf{x}) = \Psi_k^\prime(\textbf{x}) \ast {h_{ - d}}(\textbf{x}) .$$
An update of $ {o_k}(\textbf{x}) $ in the illuminated region, $ {o_{k + 1}}(\textbf{x}) $, is calculated through the following:
$$\begin{split}{o_{k + 1}}(\textbf{x}) &= {o_k}(\textbf{x}) + {\alpha ^{(o)}} \frac{{p_k^{\ast} (\textbf{x} + {\textbf{x}_k})}}{{\max |{p_k}(\textbf{x} + {\textbf{x}_k}{{)|}^2}}}\\&\quad\times [\psi_k^\prime(\textbf{x} + {\textbf{x}_k}) - {\psi _k}(\textbf{x} + {\textbf{x}_k})] ,\end{split}$$
where $ 0 \lt {\alpha ^{(o)}} \le 1 $ tunes the weight of the update. Three derivations of Eq. (25) have been provided in [171]. $ {o_{k + 1}}(\textbf{x}) $ is then used in Eq. (21), where the shift $ {\textbf{x}_{k + 1}} $ is used, and the above procedure repeats, until all the shifts have been used once, which completes one iteration of the algorithm. At the end of each iteration, the convergence of the reconstruction is evaluated through an appropriate error metric so that when the error becomes lower than a predefined threshold, the algorithm terminates.
 figure: Fig. 9.

Fig. 9. Ptychographic reconstruction of a pure amplitude object in the shape of a nine-spoked Siemens star, shown in (a). (b), (d), (f), (c), (e), (g) Diffraction patterns obtained by illuminating the simulated [real] object at the positions enclosed by the circles shown in (a) with the corresponding color. (h) , (i) Amplitude and (j) , (k) phase of the reconstructed object. The insets show the reconstructed probes (left column: simulated probe; right column: real probe; top: amplitude; bottom: phase). All the amplitude distributions share the same color bar next to (a), and all the phase distributions share the same color bar between (j) and (k). Adapted with permission from [86] The Optical Society.

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 figure: Fig. 10.

Fig. 10. Intensity (label 1) and phase (label 2) of the ptychographic reconstructions with and without correction of the scan positions. (a) Reconstruction of the object after 30 iterations of the ePIE algorithm and (b) after 30 iterations of the ccPIE algorithm; (c) , (d) reconstruction of the object [probe] after 30 iterations of the ccPIE algorithm and 20 iterations of the pcPIE algorithm. Scale bars: 1 mm. Adapted with permission from [109] The Optical Society.

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Some steps of the reconstruction process of a simulated binary Siemens star are displayed in Fig. 8. After using the top left diffraction pattern once, the reconstruction in Figs. 8(b) and 8(c) is obtained. Using all the diffraction patterns yields the reconstruction in Figs. 8(d) and 8(e) after the first iteration. A considerable improvement is obtained after the $ {100^{\text{th}}} $ iteration, especially in the estimation of the phase of the object transmission function [Figs. 8(f) and 8(g)].

Being a phase retrieval technique, ptychography reconstructs the object function by increasing the oversampling ratio with a combination of the two methods listed in Section 3.D. Collecting multiple diffraction patterns, here while translating the object as opposed to typical phase retrieval techniques, where the detector is moved, increases the total number of measured pixels by a factor as high as $ K $ and depending on the amount of overlap of the scan. Additionally, the update of the object function is performed only in the illuminated region at each step, which represents a subset of the pixels with unknown value, thus setting a support constraint given by the size of the probe. A comparison between ptychography and the phase retrieval technique presented in Section 3.D.3 is discussed in [36]. Among the numerous studies aiming at reducing the effect of experimental inaccuracies, THz ptychography has benefited from solutions coping with wrong estimates of the probe function [86] and of the shifts [109], which will be reviewed in what follows.

Extended PIE (ePIE) algorithm: the PIE algorithm assumes that the probe function $ p(\textbf{x}) $ is known a priori, which usually requires its reconstruction by measuring its diffraction pattern without the object.

A closer look at Eq. (21) shows that the probe and the object function could be swapped, with no effect on the computation of the exit wave. In other words, one can conversely regard Eq. (21) as if the object illuminated the probe, and the latter has to be recovered. This suggests that it must be possible to update the reconstruction of the probe alongside that of the object, such that Eq. (21) becomes

$${\psi _k}(\textbf{x}) = {p_k}(\textbf{x}) {o_k}(\textbf{x} - {\textbf{x}_k}) ,$$
where $ {p_k}(\textbf{x}) $ is the $ k $th estimate of the probe function. Maiden and Rodenburg proposed the ePIE [164] by allowing the probe to be updated in a way analogous to the object, as follows:
$$\begin{split}{p_{k + 1}}(\textbf{x}) = {p_k}(\textbf{x}) + {\alpha ^{(p)}} \frac{{o_k^{\ast} (\textbf{x} - {\textbf{x}_k})}}{{\max |{o_k}(\textbf{x} - {\textbf{x}_k}{{)|}^2}}} [\psi^\prime_k(\textbf{x}) - {\psi_k}(\textbf{x})] ,\end{split}$$
where the feedback constant for the update of the probe has been indicated with $ {\alpha ^{(p)}} $. The algorithm then proceeds like a standard PIE.

Through the ePIE algorithm, Valzania et al. reconstructed both amplitude and phase objects, reaching a lateral resolution of about $ 2\lambda $ and a depth resolution of $ \lambda /30 $ [86], and demonstrated that THz ptychography shares the same intrinsic resolution factors as THz off-axis digital holography [172]. Figure 9 summarizes some reconstruction steps. The imaged object was the nine-spoked Siemens star depicted in Fig. 9(a). Figures 9(b), 9(d), and 9(f) show the diffraction patterns cast by a simulated version of the object, when it was illuminated in the regions enclosed by the colored circles in Fig. 9(a), whereas Figs. 9(c), 9(e), and 9(g) contain the corresponding diffraction patterns from a real metallic nine-spoked Siemens star. The reconstructed amplitude and phase from simulated [real] data are shown in Figs. 9(h)9(k)], respectively. The final estimates of the probe can be found in the nearby insets (simulated probe in the left-hand column and real probe in the right-hand column; amplitude on the top row, phase on the bottom row).

Position-correcting PIE (pcPIE) algorithm: a second source of errors degrading ptychographic reconstructions is the inaccuracy in the knowledge of the shifts. We should expect such inaccuracies to have a considerable effect when they amount to a fraction of the desired lateral resolution. On one hand, this does not pose a problem with THz radiation, as the step resolution of motorized translation stages is currently more than two orders of magnitude smaller than typical THz wavelengths. On the other hand, unwanted angular tilts between the object and the detector plane, which are likely when the object has a maximum thickness of only few $ \lambda $, introduce uncertainties on the knowledge of the shifts, and should be taken into account even when using THz radiation. For example, assuming shifts $ \Delta x = 8\lambda $ [109] applied to an object tilted by $ \delta { = 7^ \circ } $ with respect to the detector plane leads to an error in the estimation of the shifts of $ \Delta x[1 - \cos (\delta )] \approx \lambda /10 $, 20% of the theoretical resolution limit for the lateral resolution, as well as to a wrong reconstruction distance by $ \Delta x \sin (\delta ) \approx \lambda $.

A “trial and error” algorithm, which can correct the scan positions, was proposed under the name of pcPIE [166]. The algorithm is an extension of the ePIE method, and therefore it is included in an ePIE iteration. The estimate of the exit wave at the object plane, corresponding to the $ k $th diffraction pattern, is computed in a way similar to Eq. (26), however by allowing for a correction $ {\textbf{c}_k} $ to the nominal shift $ {\textbf{x}_k} $:

$${\psi _{k0}}(\textbf{x}) = {p_k}(\textbf{x}) {o_k}(\textbf{x} - ({\textbf{x}_k} + {\textbf{c}_k})) .$$
At each new iteration, the corrections $ {\textbf{c}_k} $ are refined by constructing $ M $ alternative estimates of $ {\psi _k} $, denoted with $ {\psi _{km}} $, $ m = 1,2,\ldots,M $, with $ M $ different offsets, randomly chosen within a distance $ c $ from the starting position at $ {\textbf{x}_k} + {\textbf{c}_k} $, as follows:
$${\psi _{\textit{km}}}(\textbf{x}) = {p_k}(\textbf{x}) {o_k}(\textbf{x} - ({\textbf{x}_k} + {\textbf{c}_k} + c{\boldsymbol{\Delta}_m})) ,$$
where both components of $ {\boldsymbol{\Delta}_m} $ are selected from a uniform probability distribution within the range [−1, 1]. Equations (28) and (29) make up a set of estimates for $ {\psi _k} $, which are propagated to the detector plane, i.e.,
$${\Psi _{kn}}(\textbf{x}) = {\psi _{kn}}(\textbf{x}) \ast {h_d}(\textbf{x}) ,n = 0,1,\ldots,M,$$
and evaluated again using an appropriate error metric. The estimate of the wavefront at the detector plane leading to the minimum error, denoted with $ {\Psi _{kn^{\prime} }}(\textbf{x}) $, is then modified according to the intensity constraint and back-propagated to the object plane, as in Eqs. (23) and (24). If the selected wavefront belongs to the set of newly tried wavefronts, i.e., $ n^\prime \gt 0 $, the value of $ {\textbf{c}_k} $ is replaced by $ {\textbf{c}_k} + c{\boldsymbol{\Delta}_{n^\prime }} $; otherwise, it is kept unchanged. The algorithm proceeds with the next scan position, and after all of them have been used, a new iteration starts, when a lower value of $ c $ is employed.

Cross-correlation-based PIE (ccPIE) algorithm: alternative solutions to correct the scan positions were proposed, using cross-correlation on the estimates of the object at consecutive iterations [173], or at consecutive scan positions [174]. Rong et al. [109] have recently proposed a similar method, here referred to as ccPIE, which retrieves the shifts through a cross-correlation directly performed on the exit waves at the object plane, and they demonstrated its principle with a THz laser. In a standard ePIE framework, they suggested refining the shifts after correcting the exit wave with the intensity constraint, i.e.,

$${\textbf{x}_k} \equiv \mathop {\text{arg}\,\text{max}}\limits_{_{\boldsymbol \xi }} [\psi _k^\prime (\textbf{x}) \star {\psi _1}(\textbf{x})]({\boldsymbol \xi }) ,$$
where $ \star $ denotes cross-correlation. Their method was applied to the reconstruction of a cicadas’ forewing. Owing to its thickness of about 10 µm, tilts between the object plane and the detector plane are inevitable. The ccPIE algorithm improved the reconstruction [Figs. 10(b1) and 10(b2)], compared to when only the ePIE algorithm was applied [Figs. 10(a1) and 10(a2)]. The improvements after refining the scan positions through 20 additional iterations of pcPIE [Figs. 10(c1) and 10(c2)] are more subtle.

4. CONCLUSION AND OUTLOOK

In conclusion, we have reviewed the state of the research on THz coherent lensless imaging, focusing on the tools currently available for its implementation, their combination in successful imaging setups, and image reconstruction techniques.

Several coherent THz sources allow coherent THz imaging. Gas lasers have not seen any development in the last decades; their output will remain limited by the gas volume and by the cavity size. QCLs are developing rapidly and deliver ever-higher power. Future development will be directed towards relaxed cooling conditions, eventually operating at room temperature. There is a limitation to photo mixing, even when non-linear materials are getting more and more effective, as two pump photons are needed to create one THz photon of a fraction of the energy. An improvement in photomixing THz sources could be found in array geometries, which would allow combining the output of several device elements or large area emitters. With proper control, the emission wave overlay can also be achieved in a coherent way.

The state-of-the-art detectors for lensless imaging in the 1–4 THz range are microbolometers and pyroelectric cameras. Due to the lack of high-resolution cameras in the sub-THz range, lensless imaging is still realized by scanning single-pixel detectors.

Three directions can be identified towards the future development of THz cameras for lensless imaging. The first one aims at higher resolution, by increasing the array size to values comparable to those of infrared microbolometer arrays. Note that for THz applications, using wavelengths of 100 µm and above, pixels much smaller than the wavelength are already available, and decreasing their size is not expected to crucially impact the imaging performance. The second direction points towards low-cost infrared cameras, whose small detector areas could be compensated for by synthetic aperture methods, controlled by smartphones [175]. The third direction is seeking for efficient area detectors in the sub-THz regime. Commercial area detectors with ${64} \times {64}\,\,\text{pixels}$ with a pitch of 1.5 mm are available [176], based on photon detector technology. They have already been employed in THz imaging studies for security and non-destructive testing applications, and represent good candidates for sub-THz coherent lensless imaging. An alternative has been proposed using a THz microbolometer camera, highly sensitive at sub-THz frequencies, in combination with specifically designed THz objectives for a larger field of view [177]. Such a solution is also applicable to digital holography with ingenious reference beam injection techniques, as shown in [178].

We have reviewed the digital holographic and phase retrieval techniques already implemented with THz radiation. Basically, they share the same principles as the corresponding implementations at shorter wavelengths, among which is the fact that the lateral resolution is diffraction limited. However, we have shown that in a typical THz imaging experiment, the conditions for the far-field approximation, commonly employed with visible light and x rays, are not met. It is therefore necessary to replace the Fourier transform with the Rayleigh–Sommerfeld integral (or, equivalently, the angular spectrum approach) to numerically propagate complex wavefronts.

THz off-axis digital holography was the first variant of holography demonstrated with a coherent THz source, owing to two reasons. First, it can be performed with large enough off-axis angles to separate the diffraction orders in the Fourier spectrum of the hologram, without the risk of undersampling by the detector pixels. Second, both transmission and reflection modes are allowed. The latter geometry makes it particularly appealing for imaging-absorbing objects as well.

On the contrary, in-line digital holography is based on the assumption that part of the incident beam is not diffracted by the object, which thus must be probed in transmission and smaller than the beam size or weakly absorbing. This is the case for, e.g., excised biological tissue slices, with a thickness much lower than the wavelength, which were successfully reconstructed with THz radiation. The main advantage of in-line digital holography consists of the possibility to shorten the reconstruction distance, thereby improving the resolution compared to off-axis digital holography. The compact experimental setup comes at the expense of the twin image problem. In order to cope with it, the analysis of in-line digital holograms borrowed several solutions from another category of coherent lensless imaging techniques, namely, phase retrieval.

Phase retrieval imaging techniques reconstruct the object starting from a guessed solution and improving it by imposing a support constraint or intensity constraints from a set of diffraction patterns recorded at different object–detector distances.

Ptychography, combining typical iterative phase retrieval algorithms with a setup inherited from scanning microscopy, has also been recently migrated from electron imaging, where it was originally conceived, to the THz range, and was shown to be a valuable alternative to the widespread THz off-axis digital holography. Taking advantage of the numerous ptychographic algorithms and implementations already demonstrated will make THz ptychography a powerful tool and approach it to real-life applications. For example, THz ptychography in reflection [179] would allow imaging in vivo biological samples, while a multi-slice implementation [180] would deliver coherent tomographic reconstructions without either rotating the sample, or using an interferometric approach.

In the same way as for the imaging techniques, migrating optical components to the THz range would drastically expand the capabilities of THz imaging. For instance, THz spatial light modulators (THz-SLMs) would pave the way for THz wavefront shaping [181]. THz imaging could thus benefit from the plethora of achievements obtained in biomedical optics with visible light. Crucially, this will allow using structured illumination techniques to improve the resolution [182] and imaging through multiple-scattering media [183], which can be successfully exploited in non-destructive industrial inspection with THz waves. Despite different prototypes of THz-SLMs having been demonstrated and reported in Refs. [12,13], they are far from their counterparts in the visible range.

Although this review makes it clear that THz imaging owes a lot to imaging with electrons, x rays, and visible light, we should not forget that new coherent lensless imaging techniques are being developed in the THz range, with the potential to be implemented at different wavelengths, too. In particular, we have described an innovative phase retrieval technique for imaging through a moving and scattering barrier, whose loose assumptions make it applicable wherever imaging hidden objects is an issue. Along this line, we expect that the essential role of THz radiation for today’s scientific and technological advancements will spur the THz imaging community to develop further coherent lensless imaging techniques that will prove beneficial for diverse applications and wavelength ranges.

For these reasons, we foresee a flourishing era at the interface between THz science and coherent lensless imaging techniques.

Funding

Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (200021_160078/1); European Regional Development Fund; National Natural Science Foundation of China (61675010); Beijing Nova Program (xx2018072).

Disclosures

The authors declare that there are no conflicts of interest related to this paper.

REFERENCES

1. S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017). [CrossRef]  

2. M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998). [CrossRef]  

3. R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007). [CrossRef]  

4. P. Zolliker, M. Rüggeberg, L. Valzania, and E. Hack, “Extracting wood properties from structured THz spectra: birefringence and water content,” IEEE Trans. Terahertz Sci. Technol. 7, 722–731 (2017). [CrossRef]  

5. J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019). [CrossRef]  

6. J. Dai, J. Zhang, W. Zhang, and D. Grischkowsky, “Terahertz time-domain spectroscopy characterization of the far-infrared absorption and index of refraction of high-resistivity, float-zone silicon,” J. Opt. Soc. Am. B 21, 1379–1386 (2004). [CrossRef]  

7. A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016). [CrossRef]  

8. É. Hérault, M. Hofman, F. Garet, and J.-L. Coutaz, “Observation of terahertz beam diffraction by fabrics,” Opt. Lett. 38, 2708–2710 (2013). [CrossRef]  

9. A. Redo-Sanchez, N. Laman, B. Schulkin, and T. Tongue, “Review of terahertz technology readiness assessment and applications,” J. Infrared Millim. Terahertz Waves 34, 500–518 (2013). [CrossRef]  

10. Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008). [CrossRef]  

11. S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008). [CrossRef]  

12. D. M. Mittleman, “Twenty years of terahertz imaging,” Opt. Express 26, 9417–9431 (2018). [CrossRef]  

13. H. Guerboukha, K. Nallappan, and M. Skorobogatiy, “Toward real-time terahertz imaging,” Adv. Opt. Photon. 10, 843–938 (2018). [CrossRef]  

14. C. Fattinger and D. Grischkowsky, “Point source terahertz optics,” Appl. Phys. Lett. 53, 1480–1482 (1988). [CrossRef]  

15. M. C. Nuss and J. Orenstein, “Terahertz time-domain spectroscopy,” in Millimeter and Submillimeter Wave Spectroscopy of Solids (Springer, 1998), pp. 7–50.

16. R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011). [CrossRef]  

17. D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018). [CrossRef]  

18. P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017). [CrossRef]  

19. A. Bitzer, H. Merbold, A. Thoman, T. Feurer, H. Helm, and M. Walther, “Terahertz near-field imaging of electric and magnetic resonances of a planar metamaterial,” Opt. Express 17, 3826–3834 (2009). [CrossRef]  

20. T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013). [CrossRef]  

21. W. Withayachumnankul and M. Naftaly, “Fundamentals of measurement in terahertz time-domain spectroscopy,” J. Infrared Millim. Terahertz Waves 35, 610–637 (2014). [CrossRef]  

22. N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016). [CrossRef]  

23. Y. L. Lim, K. Bertling, T. Taimre, T. Gillespie, C. Glenn, A. Robinson, D. Indjin, Y. Han, L. Li, E. H. Linfield, A. G. Davies, P. Dean, and A. D. Rakić, “Coherent imaging using laser feedback interferometry with pulsed-mode terahertz quantum cascade lasers,” Opt. Express 27, 10221–10233 (2019). [CrossRef]  

24. J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014). [CrossRef]  

25. M. Suga, Y. Sasaki, T. Sasahara, T. Yuasa, and C. Otani, “THz phase-contrast computed tomography based on Mach-Zehnder interferometer using continuous-wave source: proof of the concept,” Opt. Express 21, 25389–25402 (2013). [CrossRef]  

26. M. Heimbeck, D. Marks, D. Brady, and H. Everitt, “Terahertz interferometric synthetic aperture tomography for confocal imaging systems,” Opt. Lett. 37, 1316–1318 (2012). [CrossRef]  

27. E. J. Candès and M. B. Wakin, “An introduction to compressive sampling [a sensing/sampling paradigm that goes against the common knowledge in data acquisition],” IEEE Signal Process. Mag. 25(2), 21–30 (2008). [CrossRef]  

28. W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008). [CrossRef]  

29. W. L. Chan, M. L. Moravec, R. G. Baraniuk, and D. M. Mittleman, “Terahertz imaging with compressed sensing and phase retrieval,” Opt. Lett. 33, 974–976 (2008). [CrossRef]  

30. M. Guizar-Sicairos, Methods for Coherent Lensless Imaging and X-Ray Wavefront Measurement (University of Rochester, 2010).

31. J. R. Fienup, “Phase retrieval algorithms: a comparison,” Appl. Opt. 21, 2758–2769 (1982). [CrossRef]  

32. J. M. Rodenburg, “Ptychography and related diffractive imaging methods,” Adv. Imaging Electron Phys. 150, 87–184 (2008). [CrossRef]  

33. T. Kreis, Handbook of Holographic Interferometry: Optical and Digital Methods (Wiley, 2006).

34. K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, Terahertz Spectroscopy and Imaging (Springer, 2012), Vol. 171.

35. L. Valzania, P. Zolliker, and E. Hack, “Topography of hidden objects using THz digital holography with multi-beam interferences,” Opt. Express 25, 11038–11047 (2017). [CrossRef]  

36. L. Valzania, P. Zolliker, and E. Hack, “Coherent reconstruction of a textile and a hidden object with terahertz radiation,” Optica 6, 518–523 (2019). [CrossRef]  

37. G. P. Gallerano and S. Biedron, “Overview of terahertz radiation sources,” in Proceedings of the Free Electron Laser Conference (FEL) (2004), Vol. 1, pp. 216–221.

38. J. R. Freeman, H. E. Beere, and D. A. Ritchie, “Generation and detection of terahertz radiation,” in Terahertz Spectroscopy and Imaging, K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, eds. (Springer, 2012), pp. 1–28.

39. F. Sizov, “Terahertz radiation detectors: the state-of-the-art,” Semicond. Sci. Technol. 33, 123001 (2018). [CrossRef]  

40. A. Rogalski, Infrared and Terahertz Detectors (CRC Press, 2018).

41. A. Crocker, H. A. Gebbie, M. F. Kimmitt, and L. E. S. Mathias, “Stimulated emission in the far infra-red,” Nature 201, 250–251 (1964). [CrossRef]  

42. M. Naftaly, Terahertz Metrology (Artech House, 2015).

43. H. Minamide and H. Ito, “Frequency-agile terahertz-wave generation and detection using a nonlinear optical conversion, and their applications for imaging,” C. R. Phys. 11, 457–471 (2010). [CrossRef]  

44. S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011). [CrossRef]  

45. Y. J. Ding, “Progress in terahertz sources based on difference-frequency generation,” J. Opt. Soc. Am. B 31, 2696–2711 (2014). [CrossRef]  

46. F. D. J. Brunner, S. H. Lee, O. P. Kwon, and T. Feurer, “THz generation by optical rectification of near-infrared laser pulses in the organic nonlinear optical crystal HMQ-TMS,” Opt. Mater. Express 4, 1586–1592 (2014). [CrossRef]  

47. M. Jazbinsek, U. Puc, A. Abina, and A. Zidansek, “Organic crystals for THz photonics,” Appl. Sci. 9, 882 (2019). [CrossRef]  

48. X. Xie, J. M. Dai, and X. C. Zhang, “Coherent control of THz wave generation in ambient air,” Phys. Rev. Lett. 96, 075005 (2006). [CrossRef]  

49. X.-C. Zhang and J. Xu, Introduction to THz Wave Photonics (Springer, 2010).

50. I. Park, “Investigations of the generation of tunable continuous-wave terahertz radiation and its spectroscopic applications,” Ph. D. thesis (Technische Universität Darmstadt, 2007).

51. J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994). [CrossRef]  

52. M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002). [CrossRef]  

53. S. Kumar, “Recent progress in terahertz quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 17, 38–47 (2011). [CrossRef]  

54. X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016). [CrossRef]  

55. B. S. Williams, “Terahertz quantum-cascade lasers,” Nat. Photonics 1, 517–525 (2007). [CrossRef]  

56. J. Faist, G. Scalari, M. Fischer, and M. Beck, “Terahertz quantum cascade lasers: 10 years of active region and material progresses,” in International Conference on Infrared, Millimeter, and Terahertz Waves (2011), pp. 1–2.

57. M. A. Belkin and F. Capasso, “New frontiers in quantum cascade lasers: high performance room temperature terahertz sources,” Phys. Scripta 90, 118002 (2015). [CrossRef]  

58. S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015). [CrossRef]  

59. Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018). [CrossRef]  

60. L. Mahler, A. Tredicucci, and M. S. Vitiello, “Quantum cascade laser: a compact, low cost, solid-state source for plasma diagnostics,” J. Instrum. 7, C02018 (2012). [CrossRef]  

61. A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010). [CrossRef]  

62. O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

63. E. Starikov, P. Shiktorov, and V. Gruzinskis, “Physical mechanisms for terahertz generation,” in Ultrafast Phenomena in Semiconductors (1999), Vol. 297-2, 271–278.

64. Z. S. Gribnikov, R. R. Bashirov, and V. V. Mitin, “Negative effective mass mechanism of negative differential drift velocity and terahertz generation,” IEEE J. Sel. Top. Quantum Electron. 7, 630–640 (2001). [CrossRef]  

65. A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010). [CrossRef]  

66. A. Dobroiu, M. Yamashita, Y. N. Ohshima, Y. Morita, C. Otani, and K. Kawase, “Terahertz imaging system based on a backward-wave oscillator,” Appl. Opt. 43, 5637–5646 (2004). [CrossRef]  

67. S. Martens, B. Gompf, and M. Dressel, “Characterization of continuous-wave terahertz sources: laser mixing versus backward-wave oscillators,” Appl. Opt. 48, 5490–5496 (2009). [CrossRef]  

68. D. Fast, W. Hurlbut, and V. G. Kozlov, “Extending spectral coverage of BWOs combined with frequency multipliers to 2.6 THz,” Proc. SPIE 8261, 82610L (2012). [CrossRef]  

69. C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

70. H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).

71. J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011). [CrossRef]  

72. V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

73. V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005). [CrossRef]  

74. Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005). [CrossRef]  

75. Y. Y. Choporova, B. A. Knyazev, and M. S. Mitkov, “Classical holography in the terahertz range: recording and reconstruction techniques,” IEEE Trans. Terahertz Sci. Technol. 5, 836–844 (2015). [CrossRef]  

76. B. Knyazev, M. Dem’yanenko, and D. Esaev, “Terahertz imaging with a 160 × 120 pixel microbolometer 90-fps camera,” in Joint 32nd International Conference on Infrared and Millimeter Waves and the 15th International Conference on Terahertz Electronics (IEEE, 2007), pp. 360–361.

77. B. N. Behnken, G. Karunasiri, D. R. Chamberlin, P. R. Robrish, and J. Faist, “Real-time imaging using a 2.8 THz quantum cascade laser and uncooled infrared microbolometer camera,” Opt. Lett. 33, 440–442 (2008). [CrossRef]  

78. B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007). [CrossRef]  

79. “Ophir THz laser measurement products,” 2019, https://bit.ly/2xW12Ex.

80. L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010). [CrossRef]  

81. M. Georges, “Long-wave infrared digital holography,” in New Techniques in Digital Holography (2015), pp. 219–254.

82. E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016). [CrossRef]  

83. E. Hack and P. Zolliker, “Terahertz holography for imaging amplitude and phase objects,” Opt. Express 22, 16079–16086 (2014). [CrossRef]  

84. P. Zolliker and E. Hack, “THz holography in reflection using a high resolution microbolometer array,” Opt. Express 23, 10957–10967 (2015). [CrossRef]  

85. M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015). [CrossRef]  

86. L. Valzania, T. Feurer, P. Zolliker, and E. Hack, “Terahertz ptychography,” Opt. Lett. 43, 543–546 (2018). [CrossRef]  

87. Z. Li, Q. Yan, Y. Qin, W. Kong, G. Li, M. Zou, D. Wang, Z. You, and X. Zhou, “Sparsity-based continuous-wave terahertz lens-free on-chip holography with sub-wavelength resolution,” Opt. Express 27, 702–713 (2019). [CrossRef]  

88. N. Oda, “Uncooled bolometer-type terahertz focal plane array and camera for real-time imaging,” C. R. Phys. 11, 496–509 (2010). [CrossRef]  

89. M. Dem’yanenko, D. Esaev, V. Ovsyuk, B. Fomin, A. Aseev, B. Knyazev, G. Kulipanov, and N. Vinokurov, “Microbolometer detector arrays for the infrared and terahertz ranges,” J. Opt. Technol. 76, 739–743 (2009). [CrossRef]  

90. D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015). [CrossRef]  

91. N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015). [CrossRef]  

92. J. Oden, J. Meilhan, J. Lalanne-Dera, J.-F. Roux, F. Garet, J.-L. Coutaz, and F. Simoens, “Imaging of broadband terahertz beams using an array of antenna-coupled microbolometers operating at room temperature,” Opt. Express 21, 4817–4825 (2013). [CrossRef]  

93. F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013). [CrossRef]  

94. M. Sakhno, A. Golenkov, and F. Sizov, “Uncooled detector challenges: millimeter-wave and terahertz long channel field effect transistor and Schottky barrier diode detectors,” J. Appl. Phys. 114, 164503 (2013). [CrossRef]  

95. W. Knap and M. Dyakonov, “Field effect transistors for terahertz applications,” in Handbook of Terahertz Technology for Imaging, Sensing and Communications (Elsevier, 2013), pp. 121–155.

96. N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

97. R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013). [CrossRef]  

98. A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006). [CrossRef]  

99. M. C. Kemp, “Explosives detection by terahertz spectroscopy—a bridge too far?” IEEE Trans. Terahertz Sci. Technol. 1, 282–292 (2011). [CrossRef]  

100. M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015). [CrossRef]  

101. M. Naftaly and R. E. Miles, “Terahertz time-domain spectroscopy for material characterization,” Proc. IEEE 95, 1658–1665 (2007). [CrossRef]  

102. Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc. 49, 513–517 (2006).

103. J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004). [CrossRef]  

104. T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017). [CrossRef]  

105. S.-H. Ding, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz digital holography by use of a pyroelectric array camera,” Opt. Lett. 36, 1993–1995 (2011). [CrossRef]  

106. L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014). [CrossRef]  

107. M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017). [CrossRef]  

108. L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015). [CrossRef]  

109. L. Rong, C. Tang, D. Wang, B. Li, F. Tan, Y. Wang, and X. Shi, “Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography,” Opt. Express 27, 938–950 (2019). [CrossRef]  

110. H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016). [CrossRef]  

111. Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017). [CrossRef]  

112. M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018). [CrossRef]  

113. T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019). [CrossRef]  

114. M. Humphreys, J. Grant, I. Escorcia-Carranza, C. Accarino, M. Kenney, Y. Shah, K. Rew, and D. Cumming, “Video-rate terahertz digital holographic imaging system,” Opt. Express 26, 25805–25813 (2018). [CrossRef]  

115. R. J. Mahon, J. A. Murphy, and W. Lanigan, “Digital holography at millimetre wavelengths,” Opt. Commun. 260, 469–473 (2006). [CrossRef]  

116. C. F. Cull, D. A. Wikner, J. N. Mait, M. Mattheiss, and D. J. Brady, “Millimeter-wave compressive holography,” Appl. Opt. 49, E67–E82 (2010). [CrossRef]  

117. X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.

118. A. Tamminen, J. Ala-Laurinaho, and A. V. Raisanen, “Indirect holographic imaging at 310 GHz,” in European Radar Conference (2008), pp. 168–171.

119. M. S. Heimbeck, M. K. Kim, D. A. Gregory, and H. O. Everitt, “Terahertz digital holography using angular spectrum and dual wavelength reconstruction methods,” Opt. Express 19, 9192–9200 (2011). [CrossRef]  

120. G. Hislop, L. Li, and A. Hellicar, “Phase retrieval for millimeter-and submillimeter-wave imaging,” IEEE Trans. Antennas Propag. 57, 286–290 (2009). [CrossRef]  

121. H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017). [CrossRef]  

122. Q. Li, S. Ding, Y. Li, K. Xue, and Q. Wang, “Experimental research on resolution improvement in CW THz digital holography,” Appl. Phys. B 107, 103–110 (2012). [CrossRef]  

123. J. Hu, Q. Li, and S. Cui, “Research on object-plane constraints and hologram expansion in phase retrieval algorithms for continuous-wave terahertz inline digital holography reconstruction,” Appl. Opt. 53, 7112–7119 (2014). [CrossRef]  

124. J. Hu, Q. Li, and Y. Zhou, “Support-domain constrained phase retrieval algorithms in terahertz in-line digital holography reconstruction of a nonisolated amplitude object,” Appl. Opt. 55, 379–386 (2016). [CrossRef]  

125. H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015). [CrossRef]  

126. D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019). [CrossRef]  

127. H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018). [CrossRef]  

128. Y. Zhao, J.-F. Vandenrijt, M. Kirkove, and M. P. Georges, “Imaging quality and resolution enhancement by iterative phase retrieval in THz off-axis digital holography,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-3.

129. J. W. Goodman, Introduction to Fourier Optics (Roberts and Company, 2005).

130. J. Rodenburg, A. Hurst, and A. Cullis, “Transmission microscopy without lenses for objects of unlimited size,” Ultramicroscopy 107, 227–231 (2007). [CrossRef]  

131. D. Gabor, “A new microscopic principle,” Nature 161, 777–778 (1948). [CrossRef]  

132. U. Schnars and W. Jueptner, Digital Holography: Digital Hologram Recording, Numerical Reconstruction, and Related Techniques (Springer, 2005).

133. P. Picart, New Techniques in Digital Holography (Wiley, 2015).

134. P. Ferraro, A. Wax, and Z. Zalevsky, Coherent Light Microscopy: Imaging and Quantitative Phase Analysis (Springer, 2011), Vol. 46.

135. P. K. Rastogi and E. Hack, Optical Methods for Solid Mechanics: A Full-Field Approach (Wiley, 2012).

136. L. Valzania, Coherent Lensless Imaging Techniques Using Terahertz Radiation (University of Bern. Institute of Applied Physics, 2019).

137. M. Takeda, H. Ina, and S. Kobayashi, “Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry,” J. Opt. Soc. Am. 72, 156–160 (1982). [CrossRef]  

138. K. Matsushima, H. Schimmel, and F. Wyrowski, “Fast calculation method for optical diffraction on tilted planes by use of the angular spectrum of plane waves,” J. Opt. Soc. Am. A 20, 1755–1762 (2003). [CrossRef]  

139. K. Matsushima, “Formulation of the rotational transformation of wave fields and their application to digital holography,” Appl. Opt. 47, D110–D116 (2008). [CrossRef]  

140. R. Mahon, A. Murphy, and W. Lanigan, “Terahertz holographic image reconstruction and analysis,” in Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference and 12th International Conference on Terahertz Electronics (IEEE, 2004), pp. 749–750.

141. X. Wang, L. Hou, and Y. Zhang, “Continuous-wave terahertz interferometry with multiwavelength phase unwrapping,” Appl. Opt. 49, 5095–5102 (2010). [CrossRef]  

142. T. Nguyen, J. Valera, and A. Moore, “Optical thickness measurement with multi-wavelength THz interferometry,” Opt. Lasers Eng. 61, 19–22 (2014). [CrossRef]  

143. R. Bamler and P. Hartl, “Synthetic aperture radar interferometry,” Inverse Prob. 14, R1–R54 (1998). [CrossRef]  

144. M. Guizar-Sicairos, S. T. Thurman, and J. R. Fienup, “Efficient subpixel image registration algorithms,” Opt. Lett. 33, 156–158 (2008). [CrossRef]  

145. T. Latychevskaia and H.-W. Fink, “Solution to the twin image problem in holography,” Phys. Rev. Lett. 98, 233901 (2007). [CrossRef]  

146. G. Koren, F. Polack, and D. Joyeux, “Iterative algorithms for twin-image elimination in in-line holography using finite-support constraints,” J. Opt. Soc. Am. A 10, 423–433 (1993). [CrossRef]  

147. L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013). [CrossRef]  

148. K. Xue, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz in-line digital holography,” Opt. Lett. 37, 3228–3230 (2012). [CrossRef]  

149. Z. Li, L. Li, Y. Qin, G. Li, D. Wang, and X. Zhou, “Resolution and quality enhancement in terahertz in-line holography by sub-pixel sampling with double-distance reconstruction,” Opt. Express 24, 21134–21146 (2016). [CrossRef]  

150. T. Latychevskaia and H.-W. Fink, “Resolution enhancement in digital holography by self-extrapolation of holograms,” Opt. Express 21, 7726–7733 (2013). [CrossRef]  

151. G. Chen and Q. Li, “Markov chain Monte Carlo sampling based terahertz holography image denoising,” Appl. Opt. 54, 4345–4351 (2015). [CrossRef]  

152. J. Miao, D. Sayre, and H. Chapman, “Phase retrieval from the magnitude of the Fourier transforms of nonperiodic objects,” J. Opt. Soc. Am. A 15, 1662–1669 (1998). [CrossRef]  

153. R. W. Gerchberg, “A practical algorithm for the determination of phase from image and diffraction plane pictures,” Optik 35, 237–246 (1972).

154. G. Pedrini, W. Osten, and Y. Zhang, “Wave-front reconstruction from a sequence of interferograms recorded at different planes,” Opt. Lett. 30, 833–835 (2005). [CrossRef]  

155. G. Hislop, G. C. James, and A. Hellicar, “Phase retrieval of scattered fields,” IEEE Trans. Antennas Propag. 55, 2332–2341 (2007). [CrossRef]  

156. P. Almoro, G. Pedrini, and W. Osten, “Complete wavefront reconstruction using sequential intensity measurements of a volume speckle field,” Appl. Opt. 45, 8596–8605 (2006). [CrossRef]  

157. N. V. Petrov, V. G. Bespalov, and M. V. Volkov, “Phase retrieval of THz radiation using set of 2D spatial intensity measurements with different wavelengths,” Proc. SPIE 8281, 82810J (2012). [CrossRef]  

158. N. V. Petrov, A. N. Galiaskarov, T. Y. Nikolaeva, and V. G. Bespalov, “The features of optimization of a phase retrieval technique in THz frequency range,” Proc. SPIE 8413, 84131T (2012). [CrossRef]  

159. L. Valzania, P. Zolliker, and E. Hack, “Coherent terahertz imaging of a textile and a hidden object,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-2.

160. W. Hoppe, “Diffraction in inhomogeneous primary wave fields. 1. Principle of phase determination from electron diffraction interference,” Acta Crystallogr. A 25, 495–501 (1969). [CrossRef]  

161. J. M. Rodenburg and H. M. Faulkner, “A phase retrieval algorithm for shifting illumination,” Appl. Phys. Lett. 85, 4795–4797 (2004). [CrossRef]  

162. P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008). [CrossRef]  

163. P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009). [CrossRef]  

164. A. M. Maiden and J. M. Rodenburg, “An improved ptychographical phase retrieval algorithm for diffractive imaging,” Ultramicroscopy 109, 1256–1262 (2009). [CrossRef]  

165. P. Thibault and A. Menzel, “Reconstructing state mixtures from diffraction measurements,” Nature 494, 68–71 (2013). [CrossRef]  

166. A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012). [CrossRef]  

167. F. Pfeiffer, “X-ray ptychography,” Nat. Photonics 12, 9–17 (2018). [CrossRef]  

168. D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl Jr., C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017). [CrossRef]  

169. O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008). [CrossRef]  

170. E. H. Tsai, I. Usov, A. Diaz, A. Menzel, and M. Guizar-Sicairos, “X-ray ptychography with extended depth of field,” Opt. Express 24, 29089–29108 (2016). [CrossRef]  

171. A. Maiden, D. Johnson, and P. Li, “Further improvements to the ptychographical iterative engine,” Optica 4, 736–745 (2017). [CrossRef]  

172. L. Valzania, E. Hack, P. Zolliker, R. Brönnimann, and T. Feurer, “Resolution limits of terahertz ptychography,” Proc. SPIE 10677, 1067720 (2018). [CrossRef]  

173. F. Zhang, I. Peterson, J. Vila-Comamala, A. Diaz, F. Berenguer, R. Bean, B. Chen, A. Menzel, I. K. Robinson, and J. M. Rodenburg, “Translation position determination in ptychographic coherent diffraction imaging,” Opt. Express 21, 13592–13606 (2013). [CrossRef]  

174. P. Dwivedi, A. Konijnenberg, S. Pereira, and H. Urbach, “An alternative method to correct translation positions in ptychography,” Proc. SPIE 10677, 106772A (2018). [CrossRef]  

175. F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).

176. “Terasense imaging products,” 2019, https://bit.ly/2GDqd4A.

177. L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014). [CrossRef]  

178. I. Alexeenko, J.-F. Vandenrijt, G. Pedrini, C. Thizy, B. Vollheim, W. Osten, and M. P. Georges, “Nondestructive testing by using long-wave infrared interferometric techniques with CO2 lasers and microbolometer arrays,” Appl. Opt. 52, A56–A67 (2013). [CrossRef]  

179. M. D. Seaberg, B. Zhang, D. F. Gardner, E. R. Shanblatt, M. M. Murnane, H. C. Kapteyn, and D. E. Adams, “Tabletop nanometer extreme ultraviolet imaging in an extended reflection mode using coherent Fresnel ptychography,” Optica 1, 39–44 (2014). [CrossRef]  

180. A. M. Maiden, M. J. Humphry, and J. Rodenburg, “Ptychographic transmission microscopy in three dimensions using a multi-slice approach,” J. Opt. Soc. Am. A 29, 1606–1614 (2012). [CrossRef]  

181. R. Horstmeyer, H. Ruan, and C. Yang, “Guidestar-assisted wavefront-shaping methods for focusing light into biological tissue,” Nat. Photonics 9, 563–571 (2015). [CrossRef]  

182. L.-H. Yeh, L. Tian, and L. Waller, “Structured illumination microscopy with unknown patterns and a statistical prior,” Biomed. Opt. Express 8, 695–711 (2017). [CrossRef]  

183. A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, “Controlling waves in space and time for imaging and focusing in complex media,” Nat. Photonics 6, 283–292 (2012). [CrossRef]  

References

  • View by:

  1. S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
    [Crossref]
  2. M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
    [Crossref]
  3. R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
    [Crossref]
  4. P. Zolliker, M. Rüggeberg, L. Valzania, and E. Hack, “Extracting wood properties from structured THz spectra: birefringence and water content,” IEEE Trans. Terahertz Sci. Technol. 7, 722–731 (2017).
    [Crossref]
  5. J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019).
    [Crossref]
  6. J. Dai, J. Zhang, W. Zhang, and D. Grischkowsky, “Terahertz time-domain spectroscopy characterization of the far-infrared absorption and index of refraction of high-resistivity, float-zone silicon,” J. Opt. Soc. Am. B 21, 1379–1386 (2004).
    [Crossref]
  7. A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
    [Crossref]
  8. É. Hérault, M. Hofman, F. Garet, and J.-L. Coutaz, “Observation of terahertz beam diffraction by fabrics,” Opt. Lett. 38, 2708–2710 (2013).
    [Crossref]
  9. A. Redo-Sanchez, N. Laman, B. Schulkin, and T. Tongue, “Review of terahertz technology readiness assessment and applications,” J. Infrared Millim. Terahertz Waves 34, 500–518 (2013).
    [Crossref]
  10. Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008).
    [Crossref]
  11. S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
    [Crossref]
  12. D. M. Mittleman, “Twenty years of terahertz imaging,” Opt. Express 26, 9417–9431 (2018).
    [Crossref]
  13. H. Guerboukha, K. Nallappan, and M. Skorobogatiy, “Toward real-time terahertz imaging,” Adv. Opt. Photon. 10, 843–938 (2018).
    [Crossref]
  14. C. Fattinger and D. Grischkowsky, “Point source terahertz optics,” Appl. Phys. Lett. 53, 1480–1482 (1988).
    [Crossref]
  15. M. C. Nuss and J. Orenstein, “Terahertz time-domain spectroscopy,” in Millimeter and Submillimeter Wave Spectroscopy of Solids (Springer, 1998), pp. 7–50.
  16. R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
    [Crossref]
  17. D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
    [Crossref]
  18. P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
    [Crossref]
  19. A. Bitzer, H. Merbold, A. Thoman, T. Feurer, H. Helm, and M. Walther, “Terahertz near-field imaging of electric and magnetic resonances of a planar metamaterial,” Opt. Express 17, 3826–3834 (2009).
    [Crossref]
  20. T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
    [Crossref]
  21. W. Withayachumnankul and M. Naftaly, “Fundamentals of measurement in terahertz time-domain spectroscopy,” J. Infrared Millim. Terahertz Waves 35, 610–637 (2014).
    [Crossref]
  22. N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016).
    [Crossref]
  23. Y. L. Lim, K. Bertling, T. Taimre, T. Gillespie, C. Glenn, A. Robinson, D. Indjin, Y. Han, L. Li, E. H. Linfield, A. G. Davies, P. Dean, and A. D. Rakić, “Coherent imaging using laser feedback interferometry with pulsed-mode terahertz quantum cascade lasers,” Opt. Express 27, 10221–10233 (2019).
    [Crossref]
  24. J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
    [Crossref]
  25. M. Suga, Y. Sasaki, T. Sasahara, T. Yuasa, and C. Otani, “THz phase-contrast computed tomography based on Mach-Zehnder interferometer using continuous-wave source: proof of the concept,” Opt. Express 21, 25389–25402 (2013).
    [Crossref]
  26. M. Heimbeck, D. Marks, D. Brady, and H. Everitt, “Terahertz interferometric synthetic aperture tomography for confocal imaging systems,” Opt. Lett. 37, 1316–1318 (2012).
    [Crossref]
  27. E. J. Candès and M. B. Wakin, “An introduction to compressive sampling [a sensing/sampling paradigm that goes against the common knowledge in data acquisition],” IEEE Signal Process. Mag. 25(2), 21–30 (2008).
    [Crossref]
  28. W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
    [Crossref]
  29. W. L. Chan, M. L. Moravec, R. G. Baraniuk, and D. M. Mittleman, “Terahertz imaging with compressed sensing and phase retrieval,” Opt. Lett. 33, 974–976 (2008).
    [Crossref]
  30. M. Guizar-Sicairos, Methods for Coherent Lensless Imaging and X-Ray Wavefront Measurement (University of Rochester, 2010).
  31. J. R. Fienup, “Phase retrieval algorithms: a comparison,” Appl. Opt. 21, 2758–2769 (1982).
    [Crossref]
  32. J. M. Rodenburg, “Ptychography and related diffractive imaging methods,” Adv. Imaging Electron Phys. 150, 87–184 (2008).
    [Crossref]
  33. T. Kreis, Handbook of Holographic Interferometry: Optical and Digital Methods (Wiley, 2006).
  34. K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, Terahertz Spectroscopy and Imaging (Springer, 2012), Vol. 171.
  35. L. Valzania, P. Zolliker, and E. Hack, “Topography of hidden objects using THz digital holography with multi-beam interferences,” Opt. Express 25, 11038–11047 (2017).
    [Crossref]
  36. L. Valzania, P. Zolliker, and E. Hack, “Coherent reconstruction of a textile and a hidden object with terahertz radiation,” Optica 6, 518–523 (2019).
    [Crossref]
  37. G. P. Gallerano and S. Biedron, “Overview of terahertz radiation sources,” in Proceedings of the Free Electron Laser Conference (FEL) (2004), Vol. 1, pp. 216–221.
  38. J. R. Freeman, H. E. Beere, and D. A. Ritchie, “Generation and detection of terahertz radiation,” in Terahertz Spectroscopy and Imaging, K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, eds. (Springer, 2012), pp. 1–28.
  39. F. Sizov, “Terahertz radiation detectors: the state-of-the-art,” Semicond. Sci. Technol. 33, 123001 (2018).
    [Crossref]
  40. A. Rogalski, Infrared and Terahertz Detectors (CRC Press, 2018).
  41. A. Crocker, H. A. Gebbie, M. F. Kimmitt, and L. E. S. Mathias, “Stimulated emission in the far infra-red,” Nature 201, 250–251 (1964).
    [Crossref]
  42. M. Naftaly, Terahertz Metrology (Artech House, 2015).
  43. H. Minamide and H. Ito, “Frequency-agile terahertz-wave generation and detection using a nonlinear optical conversion, and their applications for imaging,” C. R. Phys. 11, 457–471 (2010).
    [Crossref]
  44. S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011).
    [Crossref]
  45. Y. J. Ding, “Progress in terahertz sources based on difference-frequency generation,” J. Opt. Soc. Am. B 31, 2696–2711 (2014).
    [Crossref]
  46. F. D. J. Brunner, S. H. Lee, O. P. Kwon, and T. Feurer, “THz generation by optical rectification of near-infrared laser pulses in the organic nonlinear optical crystal HMQ-TMS,” Opt. Mater. Express 4, 1586–1592 (2014).
    [Crossref]
  47. M. Jazbinsek, U. Puc, A. Abina, and A. Zidansek, “Organic crystals for THz photonics,” Appl. Sci. 9, 882 (2019).
    [Crossref]
  48. X. Xie, J. M. Dai, and X. C. Zhang, “Coherent control of THz wave generation in ambient air,” Phys. Rev. Lett. 96, 075005 (2006).
    [Crossref]
  49. X.-C. Zhang and J. Xu, Introduction to THz Wave Photonics (Springer, 2010).
  50. I. Park, “Investigations of the generation of tunable continuous-wave terahertz radiation and its spectroscopic applications,” Ph. D. thesis (Technische Universität Darmstadt, 2007).
  51. J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
    [Crossref]
  52. M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
    [Crossref]
  53. S. Kumar, “Recent progress in terahertz quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 17, 38–47 (2011).
    [Crossref]
  54. X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
    [Crossref]
  55. B. S. Williams, “Terahertz quantum-cascade lasers,” Nat. Photonics 1, 517–525 (2007).
    [Crossref]
  56. J. Faist, G. Scalari, M. Fischer, and M. Beck, “Terahertz quantum cascade lasers: 10 years of active region and material progresses,” in International Conference on Infrared, Millimeter, and Terahertz Waves (2011), pp. 1–2.
  57. M. A. Belkin and F. Capasso, “New frontiers in quantum cascade lasers: high performance room temperature terahertz sources,” Phys. Scripta 90, 118002 (2015).
    [Crossref]
  58. S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
    [Crossref]
  59. Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
    [Crossref]
  60. L. Mahler, A. Tredicucci, and M. S. Vitiello, “Quantum cascade laser: a compact, low cost, solid-state source for plasma diagnostics,” J. Instrum. 7, C02018 (2012).
    [Crossref]
  61. A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
    [Crossref]
  62. O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.
  63. E. Starikov, P. Shiktorov, and V. Gruzinskis, “Physical mechanisms for terahertz generation,” in Ultrafast Phenomena in Semiconductors (1999), Vol. 297-2, 271–278.
  64. Z. S. Gribnikov, R. R. Bashirov, and V. V. Mitin, “Negative effective mass mechanism of negative differential drift velocity and terahertz generation,” IEEE J. Sel. Top. Quantum Electron. 7, 630–640 (2001).
    [Crossref]
  65. A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
    [Crossref]
  66. A. Dobroiu, M. Yamashita, Y. N. Ohshima, Y. Morita, C. Otani, and K. Kawase, “Terahertz imaging system based on a backward-wave oscillator,” Appl. Opt. 43, 5637–5646 (2004).
    [Crossref]
  67. S. Martens, B. Gompf, and M. Dressel, “Characterization of continuous-wave terahertz sources: laser mixing versus backward-wave oscillators,” Appl. Opt. 48, 5490–5496 (2009).
    [Crossref]
  68. D. Fast, W. Hurlbut, and V. G. Kozlov, “Extending spectral coverage of BWOs combined with frequency multipliers to 2.6 THz,” Proc. SPIE 8261, 82610L (2012).
    [Crossref]
  69. C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.
  70. H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).
  71. J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
    [Crossref]
  72. V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.
  73. V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
    [Crossref]
  74. Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005).
    [Crossref]
  75. Y. Y. Choporova, B. A. Knyazev, and M. S. Mitkov, “Classical holography in the terahertz range: recording and reconstruction techniques,” IEEE Trans. Terahertz Sci. Technol. 5, 836–844 (2015).
    [Crossref]
  76. B. Knyazev, M. Dem’yanenko, and D. Esaev, “Terahertz imaging with a 160 × 120 pixel microbolometer 90-fps camera,” in Joint 32nd International Conference on Infrared and Millimeter Waves and the 15th International Conference on Terahertz Electronics (IEEE, 2007), pp. 360–361.
  77. B. N. Behnken, G. Karunasiri, D. R. Chamberlin, P. R. Robrish, and J. Faist, “Real-time imaging using a 2.8 THz quantum cascade laser and uncooled infrared microbolometer camera,” Opt. Lett. 33, 440–442 (2008).
    [Crossref]
  78. B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
    [Crossref]
  79. “Ophir THz laser measurement products,” 2019, https://bit.ly/2xW12Ex .
  80. L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
    [Crossref]
  81. M. Georges, “Long-wave infrared digital holography,” in New Techniques in Digital Holography (2015), pp. 219–254.
  82. E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
    [Crossref]
  83. E. Hack and P. Zolliker, “Terahertz holography for imaging amplitude and phase objects,” Opt. Express 22, 16079–16086 (2014).
    [Crossref]
  84. P. Zolliker and E. Hack, “THz holography in reflection using a high resolution microbolometer array,” Opt. Express 23, 10957–10967 (2015).
    [Crossref]
  85. M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
    [Crossref]
  86. L. Valzania, T. Feurer, P. Zolliker, and E. Hack, “Terahertz ptychography,” Opt. Lett. 43, 543–546 (2018).
    [Crossref]
  87. Z. Li, Q. Yan, Y. Qin, W. Kong, G. Li, M. Zou, D. Wang, Z. You, and X. Zhou, “Sparsity-based continuous-wave terahertz lens-free on-chip holography with sub-wavelength resolution,” Opt. Express 27, 702–713 (2019).
    [Crossref]
  88. N. Oda, “Uncooled bolometer-type terahertz focal plane array and camera for real-time imaging,” C. R. Phys. 11, 496–509 (2010).
    [Crossref]
  89. M. Dem’yanenko, D. Esaev, V. Ovsyuk, B. Fomin, A. Aseev, B. Knyazev, G. Kulipanov, and N. Vinokurov, “Microbolometer detector arrays for the infrared and terahertz ranges,” J. Opt. Technol. 76, 739–743 (2009).
    [Crossref]
  90. D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
    [Crossref]
  91. N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
    [Crossref]
  92. J. Oden, J. Meilhan, J. Lalanne-Dera, J.-F. Roux, F. Garet, J.-L. Coutaz, and F. Simoens, “Imaging of broadband terahertz beams using an array of antenna-coupled microbolometers operating at room temperature,” Opt. Express 21, 4817–4825 (2013).
    [Crossref]
  93. F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
    [Crossref]
  94. M. Sakhno, A. Golenkov, and F. Sizov, “Uncooled detector challenges: millimeter-wave and terahertz long channel field effect transistor and Schottky barrier diode detectors,” J. Appl. Phys. 114, 164503 (2013).
    [Crossref]
  95. W. Knap and M. Dyakonov, “Field effect transistors for terahertz applications,” in Handbook of Terahertz Technology for Imaging, Sensing and Communications (Elsevier, 2013), pp. 121–155.
  96. N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.
  97. R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
    [Crossref]
  98. A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
    [Crossref]
  99. M. C. Kemp, “Explosives detection by terahertz spectroscopy—a bridge too far?” IEEE Trans. Terahertz Sci. Technol. 1, 282–292 (2011).
    [Crossref]
  100. M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015).
    [Crossref]
  101. M. Naftaly and R. E. Miles, “Terahertz time-domain spectroscopy for material characterization,” Proc. IEEE 95, 1658–1665 (2007).
    [Crossref]
  102. Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc. 49, 513–517 (2006).
  103. J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
    [Crossref]
  104. T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017).
    [Crossref]
  105. S.-H. Ding, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz digital holography by use of a pyroelectric array camera,” Opt. Lett. 36, 1993–1995 (2011).
    [Crossref]
  106. L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
    [Crossref]
  107. M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
    [Crossref]
  108. L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
    [Crossref]
  109. L. Rong, C. Tang, D. Wang, B. Li, F. Tan, Y. Wang, and X. Shi, “Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography,” Opt. Express 27, 938–950 (2019).
    [Crossref]
  110. H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
    [Crossref]
  111. Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
    [Crossref]
  112. M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
    [Crossref]
  113. T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
    [Crossref]
  114. M. Humphreys, J. Grant, I. Escorcia-Carranza, C. Accarino, M. Kenney, Y. Shah, K. Rew, and D. Cumming, “Video-rate terahertz digital holographic imaging system,” Opt. Express 26, 25805–25813 (2018).
    [Crossref]
  115. R. J. Mahon, J. A. Murphy, and W. Lanigan, “Digital holography at millimetre wavelengths,” Opt. Commun. 260, 469–473 (2006).
    [Crossref]
  116. C. F. Cull, D. A. Wikner, J. N. Mait, M. Mattheiss, and D. J. Brady, “Millimeter-wave compressive holography,” Appl. Opt. 49, E67–E82 (2010).
    [Crossref]
  117. X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.
  118. A. Tamminen, J. Ala-Laurinaho, and A. V. Raisanen, “Indirect holographic imaging at 310 GHz,” in European Radar Conference (2008), pp. 168–171.
  119. M. S. Heimbeck, M. K. Kim, D. A. Gregory, and H. O. Everitt, “Terahertz digital holography using angular spectrum and dual wavelength reconstruction methods,” Opt. Express 19, 9192–9200 (2011).
    [Crossref]
  120. G. Hislop, L. Li, and A. Hellicar, “Phase retrieval for millimeter-and submillimeter-wave imaging,” IEEE Trans. Antennas Propag. 57, 286–290 (2009).
    [Crossref]
  121. H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
    [Crossref]
  122. Q. Li, S. Ding, Y. Li, K. Xue, and Q. Wang, “Experimental research on resolution improvement in CW THz digital holography,” Appl. Phys. B 107, 103–110 (2012).
    [Crossref]
  123. J. Hu, Q. Li, and S. Cui, “Research on object-plane constraints and hologram expansion in phase retrieval algorithms for continuous-wave terahertz inline digital holography reconstruction,” Appl. Opt. 53, 7112–7119 (2014).
    [Crossref]
  124. J. Hu, Q. Li, and Y. Zhou, “Support-domain constrained phase retrieval algorithms in terahertz in-line digital holography reconstruction of a nonisolated amplitude object,” Appl. Opt. 55, 379–386 (2016).
    [Crossref]
  125. H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015).
    [Crossref]
  126. D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
    [Crossref]
  127. H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
    [Crossref]
  128. Y. Zhao, J.-F. Vandenrijt, M. Kirkove, and M. P. Georges, “Imaging quality and resolution enhancement by iterative phase retrieval in THz off-axis digital holography,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-3.
  129. J. W. Goodman, Introduction to Fourier Optics (Roberts and Company, 2005).
  130. J. Rodenburg, A. Hurst, and A. Cullis, “Transmission microscopy without lenses for objects of unlimited size,” Ultramicroscopy 107, 227–231 (2007).
    [Crossref]
  131. D. Gabor, “A new microscopic principle,” Nature 161, 777–778 (1948).
    [Crossref]
  132. U. Schnars and W. Jueptner, Digital Holography: Digital Hologram Recording, Numerical Reconstruction, and Related Techniques (Springer, 2005).
  133. P. Picart, New Techniques in Digital Holography (Wiley, 2015).
  134. P. Ferraro, A. Wax, and Z. Zalevsky, Coherent Light Microscopy: Imaging and Quantitative Phase Analysis (Springer, 2011), Vol. 46.
  135. P. K. Rastogi and E. Hack, Optical Methods for Solid Mechanics: A Full-Field Approach (Wiley, 2012).
  136. L. Valzania, Coherent Lensless Imaging Techniques Using Terahertz Radiation (University of Bern. Institute of Applied Physics, 2019).
  137. M. Takeda, H. Ina, and S. Kobayashi, “Fourier-transform method of fringe-pattern analysis for computer-based topography and interferometry,” J. Opt. Soc. Am. 72, 156–160 (1982).
    [Crossref]
  138. K. Matsushima, H. Schimmel, and F. Wyrowski, “Fast calculation method for optical diffraction on tilted planes by use of the angular spectrum of plane waves,” J. Opt. Soc. Am. A 20, 1755–1762 (2003).
    [Crossref]
  139. K. Matsushima, “Formulation of the rotational transformation of wave fields and their application to digital holography,” Appl. Opt. 47, D110–D116 (2008).
    [Crossref]
  140. R. Mahon, A. Murphy, and W. Lanigan, “Terahertz holographic image reconstruction and analysis,” in Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference and 12th International Conference on Terahertz Electronics (IEEE, 2004), pp. 749–750.
  141. X. Wang, L. Hou, and Y. Zhang, “Continuous-wave terahertz interferometry with multiwavelength phase unwrapping,” Appl. Opt. 49, 5095–5102 (2010).
    [Crossref]
  142. T. Nguyen, J. Valera, and A. Moore, “Optical thickness measurement with multi-wavelength THz interferometry,” Opt. Lasers Eng. 61, 19–22 (2014).
    [Crossref]
  143. R. Bamler and P. Hartl, “Synthetic aperture radar interferometry,” Inverse Prob. 14, R1–R54 (1998).
    [Crossref]
  144. M. Guizar-Sicairos, S. T. Thurman, and J. R. Fienup, “Efficient subpixel image registration algorithms,” Opt. Lett. 33, 156–158 (2008).
    [Crossref]
  145. T. Latychevskaia and H.-W. Fink, “Solution to the twin image problem in holography,” Phys. Rev. Lett. 98, 233901 (2007).
    [Crossref]
  146. G. Koren, F. Polack, and D. Joyeux, “Iterative algorithms for twin-image elimination in in-line holography using finite-support constraints,” J. Opt. Soc. Am. A 10, 423–433 (1993).
    [Crossref]
  147. L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
    [Crossref]
  148. K. Xue, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz in-line digital holography,” Opt. Lett. 37, 3228–3230 (2012).
    [Crossref]
  149. Z. Li, L. Li, Y. Qin, G. Li, D. Wang, and X. Zhou, “Resolution and quality enhancement in terahertz in-line holography by sub-pixel sampling with double-distance reconstruction,” Opt. Express 24, 21134–21146 (2016).
    [Crossref]
  150. T. Latychevskaia and H.-W. Fink, “Resolution enhancement in digital holography by self-extrapolation of holograms,” Opt. Express 21, 7726–7733 (2013).
    [Crossref]
  151. G. Chen and Q. Li, “Markov chain Monte Carlo sampling based terahertz holography image denoising,” Appl. Opt. 54, 4345–4351 (2015).
    [Crossref]
  152. J. Miao, D. Sayre, and H. Chapman, “Phase retrieval from the magnitude of the Fourier transforms of nonperiodic objects,” J. Opt. Soc. Am. A 15, 1662–1669 (1998).
    [Crossref]
  153. R. W. Gerchberg, “A practical algorithm for the determination of phase from image and diffraction plane pictures,” Optik 35, 237–246 (1972).
  154. G. Pedrini, W. Osten, and Y. Zhang, “Wave-front reconstruction from a sequence of interferograms recorded at different planes,” Opt. Lett. 30, 833–835 (2005).
    [Crossref]
  155. G. Hislop, G. C. James, and A. Hellicar, “Phase retrieval of scattered fields,” IEEE Trans. Antennas Propag. 55, 2332–2341 (2007).
    [Crossref]
  156. P. Almoro, G. Pedrini, and W. Osten, “Complete wavefront reconstruction using sequential intensity measurements of a volume speckle field,” Appl. Opt. 45, 8596–8605 (2006).
    [Crossref]
  157. N. V. Petrov, V. G. Bespalov, and M. V. Volkov, “Phase retrieval of THz radiation using set of 2D spatial intensity measurements with different wavelengths,” Proc. SPIE 8281, 82810J (2012).
    [Crossref]
  158. N. V. Petrov, A. N. Galiaskarov, T. Y. Nikolaeva, and V. G. Bespalov, “The features of optimization of a phase retrieval technique in THz frequency range,” Proc. SPIE 8413, 84131T (2012).
    [Crossref]
  159. L. Valzania, P. Zolliker, and E. Hack, “Coherent terahertz imaging of a textile and a hidden object,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-2.
  160. W. Hoppe, “Diffraction in inhomogeneous primary wave fields. 1. Principle of phase determination from electron diffraction interference,” Acta Crystallogr. A 25, 495–501 (1969).
    [Crossref]
  161. J. M. Rodenburg and H. M. Faulkner, “A phase retrieval algorithm for shifting illumination,” Appl. Phys. Lett. 85, 4795–4797 (2004).
    [Crossref]
  162. P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
    [Crossref]
  163. P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009).
    [Crossref]
  164. A. M. Maiden and J. M. Rodenburg, “An improved ptychographical phase retrieval algorithm for diffractive imaging,” Ultramicroscopy 109, 1256–1262 (2009).
    [Crossref]
  165. P. Thibault and A. Menzel, “Reconstructing state mixtures from diffraction measurements,” Nature 494, 68–71 (2013).
    [Crossref]
  166. A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012).
    [Crossref]
  167. F. Pfeiffer, “X-ray ptychography,” Nat. Photonics 12, 9–17 (2018).
    [Crossref]
  168. D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
    [Crossref]
  169. O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
    [Crossref]
  170. E. H. Tsai, I. Usov, A. Diaz, A. Menzel, and M. Guizar-Sicairos, “X-ray ptychography with extended depth of field,” Opt. Express 24, 29089–29108 (2016).
    [Crossref]
  171. A. Maiden, D. Johnson, and P. Li, “Further improvements to the ptychographical iterative engine,” Optica 4, 736–745 (2017).
    [Crossref]
  172. L. Valzania, E. Hack, P. Zolliker, R. Brönnimann, and T. Feurer, “Resolution limits of terahertz ptychography,” Proc. SPIE 10677, 1067720 (2018).
    [Crossref]
  173. F. Zhang, I. Peterson, J. Vila-Comamala, A. Diaz, F. Berenguer, R. Bean, B. Chen, A. Menzel, I. K. Robinson, and J. M. Rodenburg, “Translation position determination in ptychographic coherent diffraction imaging,” Opt. Express 21, 13592–13606 (2013).
    [Crossref]
  174. P. Dwivedi, A. Konijnenberg, S. Pereira, and H. Urbach, “An alternative method to correct translation positions in ptychography,” Proc. SPIE 10677, 106772A (2018).
    [Crossref]
  175. F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).
  176. “Terasense imaging products,” 2019, https://bit.ly/2GDqd4A .
  177. L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
    [Crossref]
  178. I. Alexeenko, J.-F. Vandenrijt, G. Pedrini, C. Thizy, B. Vollheim, W. Osten, and M. P. Georges, “Nondestructive testing by using long-wave infrared interferometric techniques with CO2 lasers and microbolometer arrays,” Appl. Opt. 52, A56–A67 (2013).
    [Crossref]
  179. M. D. Seaberg, B. Zhang, D. F. Gardner, E. R. Shanblatt, M. M. Murnane, H. C. Kapteyn, and D. E. Adams, “Tabletop nanometer extreme ultraviolet imaging in an extended reflection mode using coherent Fresnel ptychography,” Optica 1, 39–44 (2014).
    [Crossref]
  180. A. M. Maiden, M. J. Humphry, and J. Rodenburg, “Ptychographic transmission microscopy in three dimensions using a multi-slice approach,” J. Opt. Soc. Am. A 29, 1606–1614 (2012).
    [Crossref]
  181. R. Horstmeyer, H. Ruan, and C. Yang, “Guidestar-assisted wavefront-shaping methods for focusing light into biological tissue,” Nat. Photonics 9, 563–571 (2015).
    [Crossref]
  182. L.-H. Yeh, L. Tian, and L. Waller, “Structured illumination microscopy with unknown patterns and a statistical prior,” Biomed. Opt. Express 8, 695–711 (2017).
    [Crossref]
  183. A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, “Controlling waves in space and time for imaging and focusing in complex media,” Nat. Photonics 6, 283–292 (2012).
    [Crossref]

2019 (9)

J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019).
[Crossref]

Y. L. Lim, K. Bertling, T. Taimre, T. Gillespie, C. Glenn, A. Robinson, D. Indjin, Y. Han, L. Li, E. H. Linfield, A. G. Davies, P. Dean, and A. D. Rakić, “Coherent imaging using laser feedback interferometry with pulsed-mode terahertz quantum cascade lasers,” Opt. Express 27, 10221–10233 (2019).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Coherent reconstruction of a textile and a hidden object with terahertz radiation,” Optica 6, 518–523 (2019).
[Crossref]

M. Jazbinsek, U. Puc, A. Abina, and A. Zidansek, “Organic crystals for THz photonics,” Appl. Sci. 9, 882 (2019).
[Crossref]

Z. Li, Q. Yan, Y. Qin, W. Kong, G. Li, M. Zou, D. Wang, Z. You, and X. Zhou, “Sparsity-based continuous-wave terahertz lens-free on-chip holography with sub-wavelength resolution,” Opt. Express 27, 702–713 (2019).
[Crossref]

L. Rong, C. Tang, D. Wang, B. Li, F. Tan, Y. Wang, and X. Shi, “Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography,” Opt. Express 27, 938–950 (2019).
[Crossref]

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).

2018 (12)

L. Valzania, E. Hack, P. Zolliker, R. Brönnimann, and T. Feurer, “Resolution limits of terahertz ptychography,” Proc. SPIE 10677, 1067720 (2018).
[Crossref]

F. Pfeiffer, “X-ray ptychography,” Nat. Photonics 12, 9–17 (2018).
[Crossref]

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

M. Humphreys, J. Grant, I. Escorcia-Carranza, C. Accarino, M. Kenney, Y. Shah, K. Rew, and D. Cumming, “Video-rate terahertz digital holographic imaging system,” Opt. Express 26, 25805–25813 (2018).
[Crossref]

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

L. Valzania, T. Feurer, P. Zolliker, and E. Hack, “Terahertz ptychography,” Opt. Lett. 43, 543–546 (2018).
[Crossref]

Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
[Crossref]

F. Sizov, “Terahertz radiation detectors: the state-of-the-art,” Semicond. Sci. Technol. 33, 123001 (2018).
[Crossref]

D. M. Mittleman, “Twenty years of terahertz imaging,” Opt. Express 26, 9417–9431 (2018).
[Crossref]

H. Guerboukha, K. Nallappan, and M. Skorobogatiy, “Toward real-time terahertz imaging,” Adv. Opt. Photon. 10, 843–938 (2018).
[Crossref]

D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
[Crossref]

P. Dwivedi, A. Konijnenberg, S. Pereira, and H. Urbach, “An alternative method to correct translation positions in ptychography,” Proc. SPIE 10677, 106772A (2018).
[Crossref]

2017 (11)

L.-H. Yeh, L. Tian, and L. Waller, “Structured illumination microscopy with unknown patterns and a statistical prior,” Biomed. Opt. Express 8, 695–711 (2017).
[Crossref]

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

P. Zolliker, M. Rüggeberg, L. Valzania, and E. Hack, “Extracting wood properties from structured THz spectra: birefringence and water content,” IEEE Trans. Terahertz Sci. Technol. 7, 722–731 (2017).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Topography of hidden objects using THz digital holography with multi-beam interferences,” Opt. Express 25, 11038–11047 (2017).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017).
[Crossref]

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

A. Maiden, D. Johnson, and P. Li, “Further improvements to the ptychographical iterative engine,” Optica 4, 736–745 (2017).
[Crossref]

2016 (8)

E. H. Tsai, I. Usov, A. Diaz, A. Menzel, and M. Guizar-Sicairos, “X-ray ptychography with extended depth of field,” Opt. Express 24, 29089–29108 (2016).
[Crossref]

Z. Li, L. Li, Y. Qin, G. Li, D. Wang, and X. Zhou, “Resolution and quality enhancement in terahertz in-line holography by sub-pixel sampling with double-distance reconstruction,” Opt. Express 24, 21134–21146 (2016).
[Crossref]

J. Hu, Q. Li, and Y. Zhou, “Support-domain constrained phase retrieval algorithms in terahertz in-line digital holography reconstruction of a nonisolated amplitude object,” Appl. Opt. 55, 379–386 (2016).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016).
[Crossref]

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
[Crossref]

2015 (12)

P. Zolliker and E. Hack, “THz holography in reflection using a high resolution microbolometer array,” Opt. Express 23, 10957–10967 (2015).
[Crossref]

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Y. Y. Choporova, B. A. Knyazev, and M. S. Mitkov, “Classical holography in the terahertz range: recording and reconstruction techniques,” IEEE Trans. Terahertz Sci. Technol. 5, 836–844 (2015).
[Crossref]

M. A. Belkin and F. Capasso, “New frontiers in quantum cascade lasers: high performance room temperature terahertz sources,” Phys. Scripta 90, 118002 (2015).
[Crossref]

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015).
[Crossref]

H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015).
[Crossref]

G. Chen and Q. Li, “Markov chain Monte Carlo sampling based terahertz holography image denoising,” Appl. Opt. 54, 4345–4351 (2015).
[Crossref]

R. Horstmeyer, H. Ruan, and C. Yang, “Guidestar-assisted wavefront-shaping methods for focusing light into biological tissue,” Nat. Photonics 9, 563–571 (2015).
[Crossref]

2014 (10)

M. D. Seaberg, B. Zhang, D. F. Gardner, E. R. Shanblatt, M. M. Murnane, H. C. Kapteyn, and D. E. Adams, “Tabletop nanometer extreme ultraviolet imaging in an extended reflection mode using coherent Fresnel ptychography,” Optica 1, 39–44 (2014).
[Crossref]

T. Nguyen, J. Valera, and A. Moore, “Optical thickness measurement with multi-wavelength THz interferometry,” Opt. Lasers Eng. 61, 19–22 (2014).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

J. Hu, Q. Li, and S. Cui, “Research on object-plane constraints and hologram expansion in phase retrieval algorithms for continuous-wave terahertz inline digital holography reconstruction,” Appl. Opt. 53, 7112–7119 (2014).
[Crossref]

L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
[Crossref]

Y. J. Ding, “Progress in terahertz sources based on difference-frequency generation,” J. Opt. Soc. Am. B 31, 2696–2711 (2014).
[Crossref]

F. D. J. Brunner, S. H. Lee, O. P. Kwon, and T. Feurer, “THz generation by optical rectification of near-infrared laser pulses in the organic nonlinear optical crystal HMQ-TMS,” Opt. Mater. Express 4, 1586–1592 (2014).
[Crossref]

E. Hack and P. Zolliker, “Terahertz holography for imaging amplitude and phase objects,” Opt. Express 22, 16079–16086 (2014).
[Crossref]

W. Withayachumnankul and M. Naftaly, “Fundamentals of measurement in terahertz time-domain spectroscopy,” J. Infrared Millim. Terahertz Waves 35, 610–637 (2014).
[Crossref]

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

2013 (13)

M. Suga, Y. Sasaki, T. Sasahara, T. Yuasa, and C. Otani, “THz phase-contrast computed tomography based on Mach-Zehnder interferometer using continuous-wave source: proof of the concept,” Opt. Express 21, 25389–25402 (2013).
[Crossref]

É. Hérault, M. Hofman, F. Garet, and J.-L. Coutaz, “Observation of terahertz beam diffraction by fabrics,” Opt. Lett. 38, 2708–2710 (2013).
[Crossref]

A. Redo-Sanchez, N. Laman, B. Schulkin, and T. Tongue, “Review of terahertz technology readiness assessment and applications,” J. Infrared Millim. Terahertz Waves 34, 500–518 (2013).
[Crossref]

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

J. Oden, J. Meilhan, J. Lalanne-Dera, J.-F. Roux, F. Garet, J.-L. Coutaz, and F. Simoens, “Imaging of broadband terahertz beams using an array of antenna-coupled microbolometers operating at room temperature,” Opt. Express 21, 4817–4825 (2013).
[Crossref]

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

M. Sakhno, A. Golenkov, and F. Sizov, “Uncooled detector challenges: millimeter-wave and terahertz long channel field effect transistor and Schottky barrier diode detectors,” J. Appl. Phys. 114, 164503 (2013).
[Crossref]

R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
[Crossref]

I. Alexeenko, J.-F. Vandenrijt, G. Pedrini, C. Thizy, B. Vollheim, W. Osten, and M. P. Georges, “Nondestructive testing by using long-wave infrared interferometric techniques with CO2 lasers and microbolometer arrays,” Appl. Opt. 52, A56–A67 (2013).
[Crossref]

F. Zhang, I. Peterson, J. Vila-Comamala, A. Diaz, F. Berenguer, R. Bean, B. Chen, A. Menzel, I. K. Robinson, and J. M. Rodenburg, “Translation position determination in ptychographic coherent diffraction imaging,” Opt. Express 21, 13592–13606 (2013).
[Crossref]

P. Thibault and A. Menzel, “Reconstructing state mixtures from diffraction measurements,” Nature 494, 68–71 (2013).
[Crossref]

L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
[Crossref]

T. Latychevskaia and H.-W. Fink, “Resolution enhancement in digital holography by self-extrapolation of holograms,” Opt. Express 21, 7726–7733 (2013).
[Crossref]

2012 (10)

K. Xue, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz in-line digital holography,” Opt. Lett. 37, 3228–3230 (2012).
[Crossref]

A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012).
[Crossref]

N. V. Petrov, V. G. Bespalov, and M. V. Volkov, “Phase retrieval of THz radiation using set of 2D spatial intensity measurements with different wavelengths,” Proc. SPIE 8281, 82810J (2012).
[Crossref]

N. V. Petrov, A. N. Galiaskarov, T. Y. Nikolaeva, and V. G. Bespalov, “The features of optimization of a phase retrieval technique in THz frequency range,” Proc. SPIE 8413, 84131T (2012).
[Crossref]

Q. Li, S. Ding, Y. Li, K. Xue, and Q. Wang, “Experimental research on resolution improvement in CW THz digital holography,” Appl. Phys. B 107, 103–110 (2012).
[Crossref]

D. Fast, W. Hurlbut, and V. G. Kozlov, “Extending spectral coverage of BWOs combined with frequency multipliers to 2.6 THz,” Proc. SPIE 8261, 82610L (2012).
[Crossref]

L. Mahler, A. Tredicucci, and M. S. Vitiello, “Quantum cascade laser: a compact, low cost, solid-state source for plasma diagnostics,” J. Instrum. 7, C02018 (2012).
[Crossref]

M. Heimbeck, D. Marks, D. Brady, and H. Everitt, “Terahertz interferometric synthetic aperture tomography for confocal imaging systems,” Opt. Lett. 37, 1316–1318 (2012).
[Crossref]

A. M. Maiden, M. J. Humphry, and J. Rodenburg, “Ptychographic transmission microscopy in three dimensions using a multi-slice approach,” J. Opt. Soc. Am. A 29, 1606–1614 (2012).
[Crossref]

A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, “Controlling waves in space and time for imaging and focusing in complex media,” Nat. Photonics 6, 283–292 (2012).
[Crossref]

2011 (7)

S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011).
[Crossref]

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

S. Kumar, “Recent progress in terahertz quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 17, 38–47 (2011).
[Crossref]

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

M. S. Heimbeck, M. K. Kim, D. A. Gregory, and H. O. Everitt, “Terahertz digital holography using angular spectrum and dual wavelength reconstruction methods,” Opt. Express 19, 9192–9200 (2011).
[Crossref]

S.-H. Ding, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz digital holography by use of a pyroelectric array camera,” Opt. Lett. 36, 1993–1995 (2011).
[Crossref]

M. C. Kemp, “Explosives detection by terahertz spectroscopy—a bridge too far?” IEEE Trans. Terahertz Sci. Technol. 1, 282–292 (2011).
[Crossref]

2010 (7)

N. Oda, “Uncooled bolometer-type terahertz focal plane array and camera for real-time imaging,” C. R. Phys. 11, 496–509 (2010).
[Crossref]

C. F. Cull, D. A. Wikner, J. N. Mait, M. Mattheiss, and D. J. Brady, “Millimeter-wave compressive holography,” Appl. Opt. 49, E67–E82 (2010).
[Crossref]

X. Wang, L. Hou, and Y. Zhang, “Continuous-wave terahertz interferometry with multiwavelength phase unwrapping,” Appl. Opt. 49, 5095–5102 (2010).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

H. Minamide and H. Ito, “Frequency-agile terahertz-wave generation and detection using a nonlinear optical conversion, and their applications for imaging,” C. R. Phys. 11, 457–471 (2010).
[Crossref]

2009 (6)

A. Bitzer, H. Merbold, A. Thoman, T. Feurer, H. Helm, and M. Walther, “Terahertz near-field imaging of electric and magnetic resonances of a planar metamaterial,” Opt. Express 17, 3826–3834 (2009).
[Crossref]

S. Martens, B. Gompf, and M. Dressel, “Characterization of continuous-wave terahertz sources: laser mixing versus backward-wave oscillators,” Appl. Opt. 48, 5490–5496 (2009).
[Crossref]

P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009).
[Crossref]

A. M. Maiden and J. M. Rodenburg, “An improved ptychographical phase retrieval algorithm for diffractive imaging,” Ultramicroscopy 109, 1256–1262 (2009).
[Crossref]

G. Hislop, L. Li, and A. Hellicar, “Phase retrieval for millimeter-and submillimeter-wave imaging,” IEEE Trans. Antennas Propag. 57, 286–290 (2009).
[Crossref]

M. Dem’yanenko, D. Esaev, V. Ovsyuk, B. Fomin, A. Aseev, B. Knyazev, G. Kulipanov, and N. Vinokurov, “Microbolometer detector arrays for the infrared and terahertz ranges,” J. Opt. Technol. 76, 739–743 (2009).
[Crossref]

2008 (11)

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
[Crossref]

O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
[Crossref]

M. Guizar-Sicairos, S. T. Thurman, and J. R. Fienup, “Efficient subpixel image registration algorithms,” Opt. Lett. 33, 156–158 (2008).
[Crossref]

K. Matsushima, “Formulation of the rotational transformation of wave fields and their application to digital holography,” Appl. Opt. 47, D110–D116 (2008).
[Crossref]

B. N. Behnken, G. Karunasiri, D. R. Chamberlin, P. R. Robrish, and J. Faist, “Real-time imaging using a 2.8 THz quantum cascade laser and uncooled infrared microbolometer camera,” Opt. Lett. 33, 440–442 (2008).
[Crossref]

Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008).
[Crossref]

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

J. M. Rodenburg, “Ptychography and related diffractive imaging methods,” Adv. Imaging Electron Phys. 150, 87–184 (2008).
[Crossref]

E. J. Candès and M. B. Wakin, “An introduction to compressive sampling [a sensing/sampling paradigm that goes against the common knowledge in data acquisition],” IEEE Signal Process. Mag. 25(2), 21–30 (2008).
[Crossref]

W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
[Crossref]

W. L. Chan, M. L. Moravec, R. G. Baraniuk, and D. M. Mittleman, “Terahertz imaging with compressed sensing and phase retrieval,” Opt. Lett. 33, 974–976 (2008).
[Crossref]

2007 (7)

R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
[Crossref]

B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
[Crossref]

B. S. Williams, “Terahertz quantum-cascade lasers,” Nat. Photonics 1, 517–525 (2007).
[Crossref]

T. Latychevskaia and H.-W. Fink, “Solution to the twin image problem in holography,” Phys. Rev. Lett. 98, 233901 (2007).
[Crossref]

G. Hislop, G. C. James, and A. Hellicar, “Phase retrieval of scattered fields,” IEEE Trans. Antennas Propag. 55, 2332–2341 (2007).
[Crossref]

M. Naftaly and R. E. Miles, “Terahertz time-domain spectroscopy for material characterization,” Proc. IEEE 95, 1658–1665 (2007).
[Crossref]

J. Rodenburg, A. Hurst, and A. Cullis, “Transmission microscopy without lenses for objects of unlimited size,” Ultramicroscopy 107, 227–231 (2007).
[Crossref]

2006 (5)

R. J. Mahon, J. A. Murphy, and W. Lanigan, “Digital holography at millimetre wavelengths,” Opt. Commun. 260, 469–473 (2006).
[Crossref]

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc. 49, 513–517 (2006).

P. Almoro, G. Pedrini, and W. Osten, “Complete wavefront reconstruction using sequential intensity measurements of a volume speckle field,” Appl. Opt. 45, 8596–8605 (2006).
[Crossref]

X. Xie, J. M. Dai, and X. C. Zhang, “Coherent control of THz wave generation in ambient air,” Phys. Rev. Lett. 96, 075005 (2006).
[Crossref]

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

2005 (4)

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005).
[Crossref]

H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).

G. Pedrini, W. Osten, and Y. Zhang, “Wave-front reconstruction from a sequence of interferograms recorded at different planes,” Opt. Lett. 30, 833–835 (2005).
[Crossref]

2004 (4)

J. M. Rodenburg and H. M. Faulkner, “A phase retrieval algorithm for shifting illumination,” Appl. Phys. Lett. 85, 4795–4797 (2004).
[Crossref]

J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[Crossref]

A. Dobroiu, M. Yamashita, Y. N. Ohshima, Y. Morita, C. Otani, and K. Kawase, “Terahertz imaging system based on a backward-wave oscillator,” Appl. Opt. 43, 5637–5646 (2004).
[Crossref]

J. Dai, J. Zhang, W. Zhang, and D. Grischkowsky, “Terahertz time-domain spectroscopy characterization of the far-infrared absorption and index of refraction of high-resistivity, float-zone silicon,” J. Opt. Soc. Am. B 21, 1379–1386 (2004).
[Crossref]

2003 (1)

2002 (1)

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

2001 (1)

Z. S. Gribnikov, R. R. Bashirov, and V. V. Mitin, “Negative effective mass mechanism of negative differential drift velocity and terahertz generation,” IEEE J. Sel. Top. Quantum Electron. 7, 630–640 (2001).
[Crossref]

1998 (3)

M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
[Crossref]

R. Bamler and P. Hartl, “Synthetic aperture radar interferometry,” Inverse Prob. 14, R1–R54 (1998).
[Crossref]

J. Miao, D. Sayre, and H. Chapman, “Phase retrieval from the magnitude of the Fourier transforms of nonperiodic objects,” J. Opt. Soc. Am. A 15, 1662–1669 (1998).
[Crossref]

1994 (1)

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
[Crossref]

1993 (1)

1988 (1)

C. Fattinger and D. Grischkowsky, “Point source terahertz optics,” Appl. Phys. Lett. 53, 1480–1482 (1988).
[Crossref]

1982 (2)

1972 (1)

R. W. Gerchberg, “A practical algorithm for the determination of phase from image and diffraction plane pictures,” Optik 35, 237–246 (1972).

1969 (1)

W. Hoppe, “Diffraction in inhomogeneous primary wave fields. 1. Principle of phase determination from electron diffraction interference,” Acta Crystallogr. A 25, 495–501 (1969).
[Crossref]

1964 (1)

A. Crocker, H. A. Gebbie, M. F. Kimmitt, and L. E. S. Mathias, “Stimulated emission in the far infra-red,” Nature 201, 250–251 (1964).
[Crossref]

1948 (1)

D. Gabor, “A new microscopic principle,” Nature 161, 777–778 (1948).
[Crossref]

Abdelsalam, D. G.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Abina, A.

M. Jazbinsek, U. Puc, A. Abina, and A. Zidansek, “Organic crystals for THz photonics,” Appl. Sci. 9, 882 (2019).
[Crossref]

Accarino, C.

Adams, D. E.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

M. D. Seaberg, B. Zhang, D. F. Gardner, E. R. Shanblatt, M. M. Murnane, H. C. Kapteyn, and D. E. Adams, “Tabletop nanometer extreme ultraviolet imaging in an extended reflection mode using coherent Fresnel ptychography,” Optica 1, 39–44 (2014).
[Crossref]

Afshari, E.

R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
[Crossref]

Aghasi, A.

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

Ajili, L.

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

Alain, C.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Ala-Laurinaho, J.

A. Tamminen, J. Ala-Laurinaho, and A. V. Raisanen, “Indirect holographic imaging at 310 GHz,” in European Radar Conference (2008), pp. 168–171.

Alexeenko, I.

Almoro, P.

Amann, M. C.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Appleby, R.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Aseev, A.

Baik, C.-W.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Bamler, R.

R. Bamler and P. Hartl, “Synthetic aperture radar interferometry,” Inverse Prob. 14, R1–R54 (1998).
[Crossref]

Baraniuk, R. G.

W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
[Crossref]

W. L. Chan, M. L. Moravec, R. G. Baraniuk, and D. M. Mittleman, “Terahertz imaging with compressed sensing and phase retrieval,” Opt. Lett. 33, 974–976 (2008).
[Crossref]

Bartalini, S.

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

Bashirov, R. R.

Z. S. Gribnikov, R. R. Bashirov, and V. V. Mitin, “Negative effective mass mechanism of negative differential drift velocity and terahertz generation,” IEEE J. Sel. Top. Quantum Electron. 7, 630–640 (2001).
[Crossref]

Bean, R.

Beaudin, G.

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Beaupré, P.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Beck, M.

J. Faist, G. Scalari, M. Fischer, and M. Beck, “Terahertz quantum cascade lasers: 10 years of active region and material progresses,” in International Conference on Infrared, Millimeter, and Terahertz Waves (2011), pp. 1–2.

Beere, H.

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

Beere, H. E.

J. R. Freeman, H. E. Beere, and D. A. Ritchie, “Generation and detection of terahertz radiation,” in Terahertz Spectroscopy and Imaging, K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, eds. (Springer, 2012), pp. 1–28.

Behnken, B. N.

B. N. Behnken, G. Karunasiri, D. R. Chamberlin, P. R. Robrish, and J. Faist, “Real-time imaging using a 2.8 THz quantum cascade laser and uncooled infrared microbolometer camera,” Opt. Lett. 33, 440–442 (2008).
[Crossref]

B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
[Crossref]

Belkin, M. A.

M. A. Belkin and F. Capasso, “New frontiers in quantum cascade lasers: high performance room temperature terahertz sources,” Phys. Scripta 90, 118002 (2015).
[Crossref]

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Berenguer, F.

Bergeron, A.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Bertling, K.

Bespalov, V. G.

N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016).
[Crossref]

N. V. Petrov, V. G. Bespalov, and M. V. Volkov, “Phase retrieval of THz radiation using set of 2D spatial intensity measurements with different wavelengths,” Proc. SPIE 8281, 82810J (2012).
[Crossref]

N. V. Petrov, A. N. Galiaskarov, T. Y. Nikolaeva, and V. G. Bespalov, “The features of optimization of a phase retrieval technique in THz frequency range,” Proc. SPIE 8413, 84131T (2012).
[Crossref]

Bevis, C.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

Biedron, S.

G. P. Gallerano and S. Biedron, “Overview of terahertz radiation sources,” in Proceedings of the Free Electron Laser Conference (FEL) (2004), Vol. 1, pp. 216–221.

Bitzer, A.

Bjarnason, J.

J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[Crossref]

Blanchard, F.

F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).

Blanchard, N.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Boehm, G.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Bøggild, P.

D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
[Crossref]

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

Bolduc, M.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

Booske, J.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Booske, J. H.

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Bousquet, B.

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

Bowman, T.

T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017).
[Crossref]

Brady, D.

Brady, D. J.

Brönnimann, R.

L. Valzania, E. Hack, P. Zolliker, R. Brönnimann, and T. Feurer, “Resolution limits of terahertz ptychography,” Proc. SPIE 10677, 1067720 (2018).
[Crossref]

Brown, E.

J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[Crossref]

Brunner, F. D. J.

Bunk, O.

P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009).
[Crossref]

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
[Crossref]

O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
[Crossref]

Burgess, J. A.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Buron, J. D.

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

But, D. B.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Campbell, L. K.

T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017).
[Crossref]

Candès, E. J.

E. J. Candès and M. B. Wakin, “An introduction to compressive sampling [a sensing/sampling paradigm that goes against the common knowledge in data acquisition],” IEEE Signal Process. Mag. 25(2), 21–30 (2008).
[Crossref]

Canioni, L.

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

Capasso, F.

M. A. Belkin and F. Capasso, “New frontiers in quantum cascade lasers: high performance room temperature terahertz sources,” Phys. Scripta 90, 118002 (2015).
[Crossref]

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
[Crossref]

Castro-Camus, E.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Celis, M.

J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[Crossref]

Cha, H. J.

H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).

Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005).
[Crossref]

Chamberlain, D.

B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
[Crossref]

Chamberlin, D. R.

Chan, T.

J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[Crossref]

Chan, W. L.

W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
[Crossref]

W. L. Chan, M. L. Moravec, R. G. Baraniuk, and D. M. Mittleman, “Terahertz imaging with compressed sensing and phase retrieval,” Opt. Lett. 33, 974–976 (2008).
[Crossref]

Chandrayan, N.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

Chang, T.

J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019).
[Crossref]

Chapman, H.

Charan, K.

W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
[Crossref]

Chattopadhyay, G.

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Chen, B.

Chen, C.

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

Chen, G.

Chen, J.

Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
[Crossref]

Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008).
[Crossref]

Cherkassky, V.

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Cherkassky, V. S.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Chevalier, C.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Cho, A. Y.

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
[Crossref]

Choporova, Y. Y.

Y. Y. Choporova, B. A. Knyazev, and M. S. Mitkov, “Classical holography in the terahertz range: recording and reconstruction techniques,” IEEE Trans. Terahertz Sci. Technol. 5, 836–844 (2015).
[Crossref]

Chu, W. D.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Cicchi, R.

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

Clarke, R.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Cocker, T. L.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Consolino, L.

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

Cooke, D. G.

F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).

Cooper, K. B.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Coquillat, D.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Coulombe, M. J.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

Coutaz, J.-L.

Couture, P.

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Crocker, A.

A. Crocker, H. A. Gebbie, M. F. Kimmitt, and L. E. S. Mathias, “Stimulated emission in the far infra-red,” Nature 201, 250–251 (1964).
[Crossref]

Cui, H.-L.

J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019).
[Crossref]

Cui, S.

Cull, C. F.

Cullis, A.

J. Rodenburg, A. Hurst, and A. Cullis, “Transmission microscopy without lenses for objects of unlimited size,” Ultramicroscopy 107, 227–231 (2007).
[Crossref]

Cumming, D.

Cumming, D. R. S.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Cunningham, J. E.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Cywinski, G.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

D’Amato, D.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Dai, J.

Dai, J. M.

X. Xie, J. M. Dai, and X. C. Zhang, “Coherent control of THz wave generation in ambient air,” Phys. Rev. Lett. 96, 075005 (2006).
[Crossref]

Danylov, A.

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Danylov, A. A.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

David, C.

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
[Crossref]

Davies, A. G.

Y. L. Lim, K. Bertling, T. Taimre, T. Gillespie, C. Glenn, A. Robinson, D. Indjin, Y. Han, L. Li, E. H. Linfield, A. G. Davies, P. Dean, and A. D. Rakić, “Coherent imaging using laser feedback interferometry with pulsed-mode terahertz quantum cascade lasers,” Opt. Express 27, 10221–10233 (2019).
[Crossref]

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Davies, G.

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

De Los Reyes, G.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

De Natale, P.

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

Dean, P.

Dem’yanenko, M.

M. Dem’yanenko, D. Esaev, V. Ovsyuk, B. Fomin, A. Aseev, B. Knyazev, G. Kulipanov, and N. Vinokurov, “Microbolometer detector arrays for the infrared and terahertz ranges,” J. Opt. Technol. 76, 739–743 (2009).
[Crossref]

B. Knyazev, M. Dem’yanenko, and D. Esaev, “Terahertz imaging with a 160 × 120 pixel microbolometer 90-fps camera,” in Joint 32nd International Conference on Infrared and Millimeter Waves and the 15th International Conference on Terahertz Electronics (IEEE, 2007), pp. 360–361.

Demers, M.

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Demmerle, F.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Deng, Q.

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

Deng, Q. H.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Dera, J. L.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Desbarats, P.

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

Desnoyers, N.

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Desroches, Y.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Dhillon, S. S.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Diaz, A.

Dickinson, J. C.

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Dierolf, M.

P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009).
[Crossref]

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
[Crossref]

O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
[Crossref]

Ding, S.

Q. Li, S. Ding, Y. Li, K. Xue, and Q. Wang, “Experimental research on resolution improvement in CW THz digital holography,” Appl. Phys. B 107, 103–110 (2012).
[Crossref]

Ding, S.-H.

Ding, Y. J.

Dobbs, R. J.

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Dobroiu, A.

Dohler, G. H.

S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011).
[Crossref]

Doi, K.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Doucet, M.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Dressel, M.

Duan, S. Q.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Duchesne, F.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Dufour, D.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

Dupont, B.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Dwivedi, P.

P. Dwivedi, A. Konijnenberg, S. Pereira, and H. Urbach, “An alternative method to correct translation positions in ptychography,” Proc. SPIE 10677, 106772A (2018).
[Crossref]

Dyakonov, M.

W. Knap and M. Dyakonov, “Field effect transistors for terahertz applications,” in Handbook of Terahertz Technology for Imaging, Sensing and Communications (Elsevier, 2013), pp. 121–155.

Dyakonova, N.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Dyakonova, N. V.

O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

Ellison, B.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

El-Shenawee, M.

T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017).
[Crossref]

Esaev, D.

M. Dem’yanenko, D. Esaev, V. Ovsyuk, B. Fomin, A. Aseev, B. Knyazev, G. Kulipanov, and N. Vinokurov, “Microbolometer detector arrays for the infrared and terahertz ranges,” J. Opt. Technol. 76, 739–743 (2009).
[Crossref]

B. Knyazev, M. Dem’yanenko, and D. Esaev, “Terahertz imaging with a 160 × 120 pixel microbolometer 90-fps camera,” in Joint 32nd International Conference on Infrared and Millimeter Waves and the 15th International Conference on Terahertz Electronics (IEEE, 2007), pp. 360–361.

Escorcia-Carranza, I.

M. Humphreys, J. Grant, I. Escorcia-Carranza, C. Accarino, M. Kenney, Y. Shah, K. Rew, and D. Cumming, “Video-rate terahertz digital holographic imaging system,” Opt. Express 26, 25805–25813 (2018).
[Crossref]

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Etayo, D.

Evans, M. J.

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

Everitt, H.

Everitt, H. O.

M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015).
[Crossref]

M. S. Heimbeck, M. K. Kim, D. A. Gregory, and H. O. Everitt, “Terahertz digital holography using angular spectrum and dual wavelength reconstruction methods,” Opt. Express 19, 9192–9200 (2011).
[Crossref]

Fabricius, N.

Faist, J.

B. N. Behnken, G. Karunasiri, D. R. Chamberlin, P. R. Robrish, and J. Faist, “Real-time imaging using a 2.8 THz quantum cascade laser and uncooled infrared microbolometer camera,” Opt. Lett. 33, 440–442 (2008).
[Crossref]

B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
[Crossref]

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
[Crossref]

J. Faist, G. Scalari, M. Fischer, and M. Beck, “Terahertz quantum cascade lasers: 10 years of active region and material progresses,” in International Conference on Infrared, Millimeter, and Terahertz Waves (2011), pp. 1–2.

Fan, L.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Fast, D.

D. Fast, W. Hurlbut, and V. G. Kozlov, “Extending spectral coverage of BWOs combined with frequency multipliers to 2.6 THz,” Proc. SPIE 8261, 82610L (2012).
[Crossref]

Fattinger, C.

C. Fattinger and D. Grischkowsky, “Point source terahertz optics,” Appl. Phys. Lett. 53, 1480–1482 (1988).
[Crossref]

Faulkner, H. M.

J. M. Rodenburg and H. M. Faulkner, “A phase retrieval algorithm for shifting illumination,” Appl. Phys. Lett. 85, 4795–4797 (2004).
[Crossref]

Feldmann, J.

M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
[Crossref]

Ferraro, P.

P. Ferraro, A. Wax, and Z. Zalevsky, Coherent Light Microscopy: Imaging and Quantitative Phase Analysis (Springer, 2011), Vol. 46.

Feurer, T.

Fice, M.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Fienup, J. R.

Fink, H.-W.

T. Latychevskaia and H.-W. Fink, “Resolution enhancement in digital holography by self-extrapolation of holograms,” Opt. Express 21, 7726–7733 (2013).
[Crossref]

T. Latychevskaia and H.-W. Fink, “Solution to the twin image problem in holography,” Phys. Rev. Lett. 98, 233901 (2007).
[Crossref]

Fink, M.

A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, “Controlling waves in space and time for imaging and focusing in complex media,” Nat. Photonics 6, 283–292 (2012).
[Crossref]

Fischer, M.

J. Faist, G. Scalari, M. Fischer, and M. Beck, “Terahertz quantum cascade lasers: 10 years of active region and material progresses,” in International Conference on Infrared, Millimeter, and Terahertz Waves (2011), pp. 1–2.

Fomin, B.

Frederique, L.

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

Freeman, J. R.

J. R. Freeman, H. E. Beere, and D. A. Ritchie, “Generation and detection of terahertz radiation,” in Terahertz Spectroscopy and Imaging, K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, eds. (Springer, 2012), pp. 1–28.

Freeman, M. R.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Fromm, J.

M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
[Crossref]

Gabor, D.

D. Gabor, “A new microscopic principle,” Nature 161, 777–778 (1948).
[Crossref]

Gagnon, L.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Galiaskarov, A. N.

N. V. Petrov, A. N. Galiaskarov, T. Y. Nikolaeva, and V. G. Bespalov, “The features of optimization of a phase retrieval technique in THz frequency range,” Proc. SPIE 8413, 84131T (2012).
[Crossref]

Gallerano, G. P.

G. P. Gallerano and S. Biedron, “Overview of terahertz radiation sources,” in Proceedings of the Free Electron Laser Conference (FEL) (2004), Vol. 1, pp. 216–221.

Gallop, J.

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

Galloway, B. R.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

Gao, H.

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

Gao, L.

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
[Crossref]

Gardner, D. F.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

M. D. Seaberg, B. Zhang, D. F. Gardner, E. R. Shanblatt, M. M. Murnane, H. C. Kapteyn, and D. E. Adams, “Tabletop nanometer extreme ultraviolet imaging in an extended reflection mode using coherent Fresnel ptychography,” Optica 1, 39–44 (2014).
[Crossref]

Garet, F.

Gatesman, A. J.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Gauch, J.

T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017).
[Crossref]

Gäumann, G.

E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
[Crossref]

Gebbie, H. A.

A. Crocker, H. A. Gebbie, M. F. Kimmitt, and L. E. S. Mathias, “Stimulated emission in the far infra-red,” Nature 201, 250–251 (1964).
[Crossref]

Gehm, M. E.

M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015).
[Crossref]

Généreux, F.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

Gensch, M.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Georges, M.

M. Georges, “Long-wave infrared digital holography,” in New Techniques in Digital Holography (2015), pp. 219–254.

Georges, M. P.

I. Alexeenko, J.-F. Vandenrijt, G. Pedrini, C. Thizy, B. Vollheim, W. Osten, and M. P. Georges, “Nondestructive testing by using long-wave infrared interferometric techniques with CO2 lasers and microbolometer arrays,” Appl. Opt. 52, A56–A67 (2013).
[Crossref]

Y. Zhao, J.-F. Vandenrijt, M. Kirkove, and M. P. Georges, “Imaging quality and resolution enhancement by iterative phase retrieval in THz off-axis digital holography,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-3.

Gerchberg, R. W.

R. W. Gerchberg, “A practical algorithm for the determination of phase from image and diffraction plane pictures,” Optik 35, 237–246 (1972).

Gidon, S.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Giles, R. H.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Gillespie, T.

Gladden, L. F.

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

Glenn, C.

Goldsmith, P.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Golenkov, A.

M. Sakhno, A. Golenkov, and F. Sizov, “Uncooled detector challenges: millimeter-wave and terahertz long channel field effect transistor and Schottky barrier diode detectors,” J. Appl. Phys. 114, 164503 (2013).
[Crossref]

Golish, D. R.

M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015).
[Crossref]

Gompf, B.

Goodhue, W.

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Goodhue, W. D.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

Goodman, J. W.

J. W. Goodman, Introduction to Fourier Optics (Roberts and Company, 2005).

Gorodetsky, A.

N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016).
[Crossref]

Gossard, A. C.

S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011).
[Crossref]

Goto, H.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Goyette, T. M.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Grant, J.

M. Humphreys, J. Grant, I. Escorcia-Carranza, C. Accarino, M. Kenney, Y. Shah, K. Rew, and D. Cumming, “Video-rate terahertz digital holographic imaging system,” Opt. Express 26, 25805–25813 (2018).
[Crossref]

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Gregory, D. A.

Gribnikov, Z. S.

Z. S. Gribnikov, R. R. Bashirov, and V. V. Mitin, “Negative effective mass mechanism of negative differential drift velocity and terahertz generation,” IEEE J. Sel. Top. Quantum Electron. 7, 630–640 (2001).
[Crossref]

Grischkowsky, D.

Gruzinskis, V.

E. Starikov, P. Shiktorov, and V. Gruzinskis, “Physical mechanisms for terahertz generation,” in Ultrafast Phenomena in Semiconductors (1999), Vol. 297-2, 271–278.

Guellec, F.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Guerboukha, H.

Guillet, J. P.

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

Guizar-Sicairos, M.

Gun-Sik, P.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Gupta, M.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Hack, E.

L. Valzania, P. Zolliker, and E. Hack, “Coherent reconstruction of a textile and a hidden object with terahertz radiation,” Optica 6, 518–523 (2019).
[Crossref]

L. Valzania, T. Feurer, P. Zolliker, and E. Hack, “Terahertz ptychography,” Opt. Lett. 43, 543–546 (2018).
[Crossref]

L. Valzania, E. Hack, P. Zolliker, R. Brönnimann, and T. Feurer, “Resolution limits of terahertz ptychography,” Proc. SPIE 10677, 1067720 (2018).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Topography of hidden objects using THz digital holography with multi-beam interferences,” Opt. Express 25, 11038–11047 (2017).
[Crossref]

P. Zolliker, M. Rüggeberg, L. Valzania, and E. Hack, “Extracting wood properties from structured THz spectra: birefringence and water content,” IEEE Trans. Terahertz Sci. Technol. 7, 722–731 (2017).
[Crossref]

E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
[Crossref]

P. Zolliker and E. Hack, “THz holography in reflection using a high resolution microbolometer array,” Opt. Express 23, 10957–10967 (2015).
[Crossref]

E. Hack and P. Zolliker, “Terahertz holography for imaging amplitude and phase objects,” Opt. Express 22, 16079–16086 (2014).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Coherent terahertz imaging of a textile and a hidden object,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-2.

P. K. Rastogi and E. Hack, Optical Methods for Solid Mechanics: A Full-Field Approach (Wiley, 2012).

Han, R.

R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
[Crossref]

Han, X.

X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.

Han, Y.

Hao, L.

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

Hartl, P.

R. Bamler and P. Hartl, “Synthetic aperture radar interferometry,” Inverse Prob. 14, R1–R54 (1998).
[Crossref]

Hauri, C. P.

E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
[Crossref]

He, Y.

Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008).
[Crossref]

Healy, J. J.

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

Hegmann, F. A.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Heimbeck, M.

Heimbeck, M. S.

M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015).
[Crossref]

M. S. Heimbeck, M. K. Kim, D. A. Gregory, and H. O. Everitt, “Terahertz digital holography using angular spectrum and dual wavelength reconstruction methods,” Opt. Express 19, 9192–9200 (2011).
[Crossref]

Hellicar, A.

G. Hislop, L. Li, and A. Hellicar, “Phase retrieval for millimeter-and submillimeter-wave imaging,” IEEE Trans. Antennas Propag. 57, 286–290 (2009).
[Crossref]

G. Hislop, G. C. James, and A. Hellicar, “Phase retrieval of scattered fields,” IEEE Trans. Antennas Propag. 55, 2332–2341 (2007).
[Crossref]

Helm, H.

Hérault, É.

Heshmat, B.

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

Hislop, G.

G. Hislop, L. Li, and A. Hellicar, “Phase retrieval for millimeter-and submillimeter-wave imaging,” IEEE Trans. Antennas Propag. 57, 286–290 (2009).
[Crossref]

G. Hislop, G. C. James, and A. Hellicar, “Phase retrieval of scattered fields,” IEEE Trans. Antennas Propag. 55, 2332–2341 (2007).
[Crossref]

Hoen, W.

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Hoffmann, M. C.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Hofman, M.

Hoppe, W.

W. Hoppe, “Diffraction in inhomogeneous primary wave fields. 1. Principle of phase determination from electron diffraction interference,” Acta Crystallogr. A 25, 495–501 (1969).
[Crossref]

Horstmeyer, R.

R. Horstmeyer, H. Ruan, and C. Yang, “Guidestar-assisted wavefront-shaping methods for focusing light into biological tissue,” Nat. Photonics 9, 563–571 (2015).
[Crossref]

Hou, L.

X. Wang, L. Hou, and Y. Zhang, “Continuous-wave terahertz interferometry with multiwavelength phase unwrapping,” Appl. Opt. 49, 5095–5102 (2010).
[Crossref]

X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.

Hu, J.

Hua Deng, Q.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Huang, H.

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015).
[Crossref]

L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
[Crossref]

Huber, R.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Huggard, P. G.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Humphreys, M.

Humphry, M.

A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012).
[Crossref]

Humphry, M. J.

Hunsche, S.

M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
[Crossref]

Hurlbut, W.

D. Fast, W. Hurlbut, and V. G. Kozlov, “Extending spectral coverage of BWOs combined with frequency multipliers to 2.6 THz,” Proc. SPIE 8261, 82610L (2012).
[Crossref]

Hurst, A.

J. Rodenburg, A. Hurst, and A. Cullis, “Transmission microscopy without lenses for objects of unlimited size,” Ultramicroscopy 107, 227–231 (2007).
[Crossref]

Hutchinson, A. L.

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
[Crossref]

Hwang, J.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Ilias, S.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Ina, H.

Indjin, D.

Ishi, T.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Ito, H.

H. Minamide and H. Ito, “Frequency-agile terahertz-wave generation and detection using a nonlinear optical conversion, and their applications for imaging,” C. R. Phys. 11, 457–471 (2010).
[Crossref]

Iwata, T.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

James, G. C.

G. Hislop, G. C. James, and A. Hellicar, “Phase retrieval of scattered fields,” IEEE Trans. Antennas Propag. 55, 2332–2341 (2007).
[Crossref]

Jansen, C.

R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
[Crossref]

Jazbinsek, M.

M. Jazbinsek, U. Puc, A. Abina, and A. Zidansek, “Organic crystals for THz photonics,” Appl. Sci. 9, 882 (2019).
[Crossref]

Jelic, V.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Jeon, S.-G.

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc. 49, 513–517 (2006).

Jeong, Y. U.

H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).

Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005).
[Crossref]

Jepsen, P. U.

D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
[Crossref]

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

Jerominek, H.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Jiang, A. T.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Jiang, T.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Jiang, Y. F.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Jin, Y.

Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
[Crossref]

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Jin, Y.-S.

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc. 49, 513–517 (2006).

Johnson, D.

Johnson, I.

O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
[Crossref]

Johnston, M. B.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Joye, C. D.

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Joyeux, D.

Jueptner, W.

U. Schnars and W. Jueptner, Digital Holography: Digital Hologram Recording, Numerical Reconstruction, and Related Techniques (Springer, 2005).

Jun, S. C.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Jung, C.

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Jung, S. Y.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Kampfrath, T.

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Kapteyn, H. C.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

M. D. Seaberg, B. Zhang, D. F. Gardner, E. R. Shanblatt, M. M. Murnane, H. C. Kapteyn, and D. E. Adams, “Tabletop nanometer extreme ultraviolet imaging in an extended reflection mode using coherent Fresnel ptychography,” Optica 1, 39–44 (2014).
[Crossref]

Karl, R.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

Karunasiri, G.

B. N. Behnken, G. Karunasiri, D. R. Chamberlin, P. R. Robrish, and J. Faist, “Real-time imaging using a 2.8 THz quantum cascade laser and uncooled infrared microbolometer camera,” Opt. Lett. 33, 440–442 (2008).
[Crossref]

B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
[Crossref]

Kawase, K.

Kazakevitch, G. M.

Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005).
[Crossref]

Kelly, K. F.

W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
[Crossref]

Kemp, M. C.

M. C. Kemp, “Explosives detection by terahertz spectroscopy—a bridge too far?” IEEE Trans. Terahertz Sci. Technol. 1, 282–292 (2011).
[Crossref]

Kenneth, K. O.

R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
[Crossref]

Kenney, M.

Kim, D. Y.

R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
[Crossref]

Kim, G.-J.

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc. 49, 513–517 (2006).

Kim, H. J.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Kim, J.-M.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Kim, J.-S.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Kim, M. K.

Kim, S. I.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Kim, Y.

R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
[Crossref]

Kimmitt, M. F.

A. Crocker, H. A. Gebbie, M. F. Kimmitt, and L. E. S. Mathias, “Stimulated emission in the far infra-red,” Nature 201, 250–251 (1964).
[Crossref]

Kira, M.

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Kirkove, M.

Y. Zhao, J.-F. Vandenrijt, M. Kirkove, and M. P. Georges, “Imaging quality and resolution enhancement by iterative phase retrieval in THz off-axis digital holography,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-3.

Klimenko, O. A.

O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

Knab, J.

Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008).
[Crossref]

Knap, W.

O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

W. Knap and M. Dyakonov, “Field effect transistors for terahertz applications,” in Handbook of Terahertz Technology for Imaging, Sensing and Communications (Elsevier, 2013), pp. 121–155.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Knyazev, B.

M. Dem’yanenko, D. Esaev, V. Ovsyuk, B. Fomin, A. Aseev, B. Knyazev, G. Kulipanov, and N. Vinokurov, “Microbolometer detector arrays for the infrared and terahertz ranges,” J. Opt. Technol. 76, 739–743 (2009).
[Crossref]

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

B. Knyazev, M. Dem’yanenko, and D. Esaev, “Terahertz imaging with a 160 × 120 pixel microbolometer 90-fps camera,” in Joint 32nd International Conference on Infrared and Millimeter Waves and the 15th International Conference on Terahertz Electronics (IEEE, 2007), pp. 360–361.

Knyazev, B. A.

Y. Y. Choporova, B. A. Knyazev, and M. S. Mitkov, “Classical holography in the terahertz range: recording and reconstruction techniques,” IEEE Trans. Terahertz Sci. Technol. 5, 836–844 (2015).
[Crossref]

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Kobayashi, S.

Koch, M.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
[Crossref]

M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
[Crossref]

Koch, S. W.

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Kong, W.

Konijnenberg, A.

P. Dwivedi, A. Konijnenberg, S. Pereira, and H. Urbach, “An alternative method to correct translation positions in ptychography,” Proc. SPIE 10677, 106772A (2018).
[Crossref]

Konishi, K.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Koren, G.

Korter, T. M.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Kory, C. L.

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Kozlov, S. V.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Kozlov, V. G.

D. Fast, W. Hurlbut, and V. G. Kozlov, “Extending spectral coverage of BWOs combined with frequency multipliers to 2.6 THz,” Proc. SPIE 8261, 82610L (2012).
[Crossref]

Kraus, B.

A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012).
[Crossref]

Kreis, T.

T. Kreis, Handbook of Holographic Interferometry: Optical and Digital Methods (Wiley, 2006).

Krozer, V.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Ku, P. I.

Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008).
[Crossref]

Kubarev, V.

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Kubarev, V. V.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Kulipanov, G.

M. Dem’yanenko, D. Esaev, V. Ovsyuk, B. Fomin, A. Aseev, B. Knyazev, G. Kulipanov, and N. Vinokurov, “Microbolometer detector arrays for the infrared and terahertz ranges,” J. Opt. Technol. 76, 739–743 (2009).
[Crossref]

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Kulipanov, G. N.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Kulya, M. S.

N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016).
[Crossref]

Kumar, S.

Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
[Crossref]

S. Kumar, “Recent progress in terahertz quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 17, 38–47 (2011).
[Crossref]

Kurashina, S.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Kürner, T.

R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
[Crossref]

Kuryshev, G.

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Kuwata-Gonokami, M.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, Terahertz Spectroscopy and Imaging (Springer, 2012), Vol. 171.

Kwon, O. P.

Kynde, S.

O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
[Crossref]

Lagacé, F.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Lagendijk, A.

A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, “Controlling waves in space and time for imaging and focusing in complex media,” Nat. Photonics 6, 283–292 (2012).
[Crossref]

Lalanne-Dera, J.

Laman, N.

A. Redo-Sanchez, N. Laman, B. Schulkin, and T. Tongue, “Review of terahertz technology readiness assessment and applications,” J. Infrared Millim. Terahertz Waves 34, 500–518 (2013).
[Crossref]

Lambert, J.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Lamontage, F.

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Lamontagne, F.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Lanigan, W.

R. J. Mahon, J. A. Murphy, and W. Lanigan, “Digital holography at millimetre wavelengths,” Opt. Commun. 260, 469–473 (2006).
[Crossref]

R. Mahon, A. Murphy, and W. Lanigan, “Terahertz holographic image reconstruction and analysis,” in Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference and 12th International Conference on Terahertz Electronics (IEEE, 2004), pp. 749–750.

Lasfargues, G.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Latychevskaia, T.

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
[Crossref]

T. Latychevskaia and H.-W. Fink, “Resolution enhancement in digital holography by self-extrapolation of holograms,” Opt. Express 21, 7726–7733 (2013).
[Crossref]

T. Latychevskaia and H.-W. Fink, “Solution to the twin image problem in holography,” Phys. Rev. Lett. 98, 233901 (2007).
[Crossref]

Le Noc, L.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Lee, A.

J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[Crossref]

Lee, B. C.

Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005).
[Crossref]

H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).

Lee, S. H.

Leinß, S.

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Leitenstorfer, A.

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Lerosey, G.

A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, “Controlling waves in space and time for imaging and focusing in complex media,” Nat. Photonics 6, 283–292 (2012).
[Crossref]

Lévesque, F.

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Li, B.

Li, G.

Li, J.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Li, L.

Li, P.

Li, Q.

Li, W.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

Li, W. H.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Li, Y.

L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
[Crossref]

Q. Li, S. Ding, Y. Li, K. Xue, and Q. Wang, “Experimental research on resolution improvement in CW THz digital holography,” Appl. Phys. B 107, 103–110 (2012).
[Crossref]

Li, Y.-D.

Li, Z.

Z. Li, Q. Yan, Y. Qin, W. Kong, G. Li, M. Zou, D. Wang, Z. You, and X. Zhou, “Sparsity-based continuous-wave terahertz lens-free on-chip holography with sub-wavelength resolution,” Opt. Express 27, 702–713 (2019).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

Z. Li, L. Li, Y. Qin, G. Li, D. Wang, and X. Zhou, “Resolution and quality enhancement in terahertz in-line holography by sub-pixel sampling with double-distance reconstruction,” Opt. Express 24, 21134–21146 (2016).
[Crossref]

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015).
[Crossref]

L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
[Crossref]

Lim, Y. L.

Linfield, E.

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

Linfield, E. H.

Y. L. Lim, K. Bertling, T. Taimre, T. Gillespie, C. Glenn, A. Robinson, D. Indjin, Y. Han, L. Li, E. H. Linfield, A. G. Davies, P. Dean, and A. D. Rakić, “Coherent imaging using laser feedback interferometry with pulsed-mode terahertz quantum cascade lasers,” Opt. Express 27, 10221–10233 (2019).
[Crossref]

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Liu, H.

X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.

Liu, L.

J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019).
[Crossref]

Liu, S.

L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
[Crossref]

Locatelli, M.

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

Lowe, M.

B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
[Crossref]

Lucyszyn, S.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Mackenzie, D. M.

D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
[Crossref]

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

Maestrini, A.

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Mahler, L.

L. Mahler, A. Tredicucci, and M. S. Vitiello, “Quantum cascade laser: a compact, low cost, solid-state source for plasma diagnostics,” J. Instrum. 7, C02018 (2012).
[Crossref]

Mahon, R.

R. Mahon, A. Murphy, and W. Lanigan, “Terahertz holographic image reconstruction and analysis,” in Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference and 12th International Conference on Terahertz Electronics (IEEE, 2004), pp. 749–750.

Mahon, R. J.

R. J. Mahon, J. A. Murphy, and W. Lanigan, “Digital holography at millimetre wavelengths,” Opt. Commun. 260, 469–473 (2006).
[Crossref]

Maiden, A.

A. Maiden, D. Johnson, and P. Li, “Further improvements to the ptychographical iterative engine,” Optica 4, 736–745 (2017).
[Crossref]

A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012).
[Crossref]

Maiden, A. M.

A. M. Maiden, M. J. Humphry, and J. Rodenburg, “Ptychographic transmission microscopy in three dimensions using a multi-slice approach,” J. Opt. Soc. Am. A 29, 1606–1614 (2012).
[Crossref]

A. M. Maiden and J. M. Rodenburg, “An improved ptychographical phase retrieval algorithm for diffractive imaging,” Ultramicroscopy 109, 1256–1262 (2009).
[Crossref]

Mait, J. N.

Malallah, R.

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

Malzer, S.

S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011).
[Crossref]

Mancini, G. F.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

Manek-Hönninger, I.

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

Marchese, L.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Marchese, L. E.

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

Marczewski, J.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Markelz, A.

Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008).
[Crossref]

Markelz, A. G.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Marks, D.

Martel, A.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Martens, S.

Marti, O.

O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
[Crossref]

Martin, S.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Mathias, L. E. S.

A. Crocker, H. A. Gebbie, M. F. Kimmitt, and L. E. S. Mathias, “Stimulated emission in the far infra-red,” Nature 201, 250–251 (1964).
[Crossref]

Matsushima, K.

Matte, D.

F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).

Mattheiss, M.

Matveenko, A.

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Matveenko, A. N.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

May, R. K.

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

Mehdi, I.

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Meilhan, J.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

J. Oden, J. Meilhan, J. Lalanne-Dera, J.-F. Roux, F. Garet, J.-L. Coutaz, and F. Simoens, “Imaging of broadband terahertz beams using an array of antenna-coupled microbolometers operating at room temperature,” Opt. Express 21, 4817–4825 (2013).
[Crossref]

Menzel, A.

E. H. Tsai, I. Usov, A. Diaz, A. Menzel, and M. Guizar-Sicairos, “X-ray ptychography with extended depth of field,” Opt. Express 24, 29089–29108 (2016).
[Crossref]

P. Thibault and A. Menzel, “Reconstructing state mixtures from diffraction measurements,” Nature 494, 68–71 (2013).
[Crossref]

F. Zhang, I. Peterson, J. Vila-Comamala, A. Diaz, F. Berenguer, R. Bean, B. Chen, A. Menzel, I. K. Robinson, and J. M. Rodenburg, “Translation position determination in ptychographic coherent diffraction imaging,” Opt. Express 21, 13592–13606 (2013).
[Crossref]

P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009).
[Crossref]

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
[Crossref]

Merbold, H.

Mercier, L.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Miao, J.

Miles, R. E.

M. Naftaly and R. E. Miles, “Terahertz time-domain spectroscopy for material characterization,” Proc. IEEE 95, 1658–1665 (2007).
[Crossref]

Minamide, H.

H. Minamide and H. Ito, “Frequency-agile terahertz-wave generation and detection using a nonlinear optical conversion, and their applications for imaging,” C. R. Phys. 11, 457–471 (2010).
[Crossref]

Minamikawa, T.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Mitin, V. V.

Z. S. Gribnikov, R. R. Bashirov, and V. V. Mitin, “Negative effective mass mechanism of negative differential drift velocity and terahertz generation,” IEEE J. Sel. Top. Quantum Electron. 7, 630–640 (2001).
[Crossref]

Mitkov, M. S.

Y. Y. Choporova, B. A. Knyazev, and M. S. Mitkov, “Classical holography in the terahertz range: recording and reconstruction techniques,” IEEE Trans. Terahertz Sci. Technol. 5, 836–844 (2015).
[Crossref]

Mittleman, D.

R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
[Crossref]

Mittleman, D. M.

D. M. Mittleman, “Twenty years of terahertz imaging,” Opt. Express 26, 9417–9431 (2018).
[Crossref]

W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
[Crossref]

W. L. Chan, M. L. Moravec, R. G. Baraniuk, and D. M. Mittleman, “Terahertz imaging with compressed sensing and phase retrieval,” Opt. Lett. 33, 974–976 (2008).
[Crossref]

Mityagin, Y. A.

O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

Miyoshi, M.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Mizutani, Y.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Molesky, S. J.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Moon, S.-W.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Moore, A.

T. Nguyen, J. Valera, and A. Moore, “Optical thickness measurement with multi-wavelength THz interferometry,” Opt. Lasers Eng. 61, 19–22 (2014).
[Crossref]

Moravec, M. L.

Morimoto, T.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Morissette, M.

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Morita, Y.

Mosk, A. P.

A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, “Controlling waves in space and time for imaging and focusing in complex media,” Nat. Photonics 6, 283–292 (2012).
[Crossref]

Mounaix, P.

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

Muniraj, I.

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

Murnane, M. M.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

M. D. Seaberg, B. Zhang, D. F. Gardner, E. R. Shanblatt, M. M. Murnane, H. C. Kapteyn, and D. E. Adams, “Tabletop nanometer extreme ultraviolet imaging in an extended reflection mode using coherent Fresnel ptychography,” Optica 1, 39–44 (2014).
[Crossref]

Murphy, A.

R. Mahon, A. Murphy, and W. Lanigan, “Terahertz holographic image reconstruction and analysis,” in Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference and 12th International Conference on Terahertz Electronics (IEEE, 2004), pp. 749–750.

Murphy, J. A.

R. J. Mahon, J. A. Murphy, and W. Lanigan, “Digital holography at millimetre wavelengths,” Opt. Commun. 260, 469–473 (2006).
[Crossref]

Murzin, V. N.

O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

Naftaly, M.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

W. Withayachumnankul and M. Naftaly, “Fundamentals of measurement in terahertz time-domain spectroscopy,” J. Infrared Millim. Terahertz Waves 35, 610–637 (2014).
[Crossref]

M. Naftaly and R. E. Miles, “Terahertz time-domain spectroscopy for material characterization,” Proc. IEEE 95, 1658–1665 (2007).
[Crossref]

M. Naftaly, Terahertz Metrology (Artech House, 2015).

Nallappan, K.

Naqvi, S.

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

Nechache, R.

F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).

Neil, G. R.

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Ng, W. R.

M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015).
[Crossref]

Nguyen, T.

T. Nguyen, J. Valera, and A. Moore, “Optical thickness measurement with multi-wavelength THz interferometry,” Opt. Lasers Eng. 61, 19–22 (2014).
[Crossref]

Nikolaeva, T. Y.

N. V. Petrov, A. N. Galiaskarov, T. Y. Nikolaeva, and V. G. Bespalov, “The features of optimization of a phase retrieval technique in THz frequency range,” Proc. SPIE 8413, 84131T (2012).
[Crossref]

Nixon, W. E.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Nkeck, J. E.

F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).

Nuss, M.

M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
[Crossref]

Nuss, M. C.

M. C. Nuss and J. Orenstein, “Terahertz time-domain spectroscopy,” in Millimeter and Submillimeter Wave Spectroscopy of Solids (Springer, 1998), pp. 7–50.

Oda, N.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

N. Oda, “Uncooled bolometer-type terahertz focal plane array and camera for real-time imaging,” C. R. Phys. 11, 496–509 (2010).
[Crossref]

Oden, J.

Ogawa, T.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Ohshima, Y. N.

Okabe, K.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Orenstein, J.

M. C. Nuss and J. Orenstein, “Terahertz time-domain spectroscopy,” in Millimeter and Submillimeter Wave Spectroscopy of Solids (Springer, 1998), pp. 7–50.

Osten, W.

Otani, C.

Oulachgar, H.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Ouvrier-Buffet, J. L.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Ovsyuk, V.

Pan, F.

L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
[Crossref]

Pancrati, O.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Panezai, S.

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

Paoloni, C.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Pardo, D.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Park, G. S.

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Park, I.

I. Park, “Investigations of the generation of tunable continuous-wave terahertz radiation and its spectroscopic applications,” Ph. D. thesis (Technische Universität Darmstadt, 2007).

Park, J.

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Park, S. H.

H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).

H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).

Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005).
[Crossref]

Paultre, J.-E.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Pavone, F.

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

Pedrini, G.

Peiponen, K.-E.

K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, Terahertz Spectroscopy and Imaging (Springer, 2012), Vol. 171.

Peng, L.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Pereira, S.

P. Dwivedi, A. Konijnenberg, S. Pereira, and H. Urbach, “An alternative method to correct translation positions in ptychography,” Proc. SPIE 10677, 106772A (2018).
[Crossref]

Petersen, D. H.

D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
[Crossref]

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

Peterson, I.

Petrov, A.

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Petrov, N. V.

N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016).
[Crossref]

N. V. Petrov, V. G. Bespalov, and M. V. Volkov, “Phase retrieval of THz radiation using set of 2D spatial intensity measurements with different wavelengths,” Proc. SPIE 8281, 82810J (2012).
[Crossref]

N. V. Petrov, A. N. Galiaskarov, T. Y. Nikolaeva, and V. G. Bespalov, “The features of optimization of a phase retrieval technique in THz frequency range,” Proc. SPIE 8413, 84131T (2012).
[Crossref]

Pfeiffer, F.

F. Pfeiffer, “X-ray ptychography,” Nat. Photonics 12, 9–17 (2018).
[Crossref]

P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009).
[Crossref]

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
[Crossref]

O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
[Crossref]

Picart, P.

P. Picart, New Techniques in Digital Holography (Wiley, 2015).

Piesiewicz, R.

R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
[Crossref]

Pocas, S.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Polack, F.

Pope, T.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Popik, V.

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Popik, V. M.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Porter, C. L.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

Preu, S.

S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011).
[Crossref]

Provençal, F.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Puc, U.

M. Jazbinsek, U. Puc, A. Abina, and A. Zidansek, “Organic crystals for THz photonics,” Appl. Sci. 9, 882 (2019).
[Crossref]

Qian, X. F.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

Qin, Y.

Qiu, P.

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

Rabaud, W.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Raisanen, A. V.

A. Tamminen, J. Ala-Laurinaho, and A. V. Raisanen, “Indirect holographic imaging at 310 GHz,” in European Radar Conference (2008), pp. 168–171.

Rakic, A. D.

Raskar, R.

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

Rastogi, P. K.

P. K. Rastogi and E. Hack, Optical Methods for Solid Mechanics: A Full-Field Approach (Wiley, 2012).

Ravaro, M.

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

Rea, S.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Recur, B.

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

Redo-Sanchez, A.

D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
[Crossref]

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

A. Redo-Sanchez, N. Laman, B. Schulkin, and T. Tongue, “Review of terahertz technology readiness assessment and applications,” J. Infrared Millim. Terahertz Waves 34, 500–518 (2013).
[Crossref]

Renaud, C.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Reno, J. L.

Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
[Crossref]

Rew, K.

Ridler, N.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Ritchie, D.

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

Ritchie, D. A.

J. R. Freeman, H. E. Beere, and D. A. Ritchie, “Generation and detection of terahertz radiation,” in Terahertz Spectroscopy and Imaging, K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, eds. (Springer, 2012), pp. 1–28.

Robinson, A.

Robinson, I. K.

Robrish, P.

B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
[Crossref]

Robrish, P. R.

Rochat, M.

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

Rodenburg, J.

A. M. Maiden, M. J. Humphry, and J. Rodenburg, “Ptychographic transmission microscopy in three dimensions using a multi-slice approach,” J. Opt. Soc. Am. A 29, 1606–1614 (2012).
[Crossref]

A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012).
[Crossref]

J. Rodenburg, A. Hurst, and A. Cullis, “Transmission microscopy without lenses for objects of unlimited size,” Ultramicroscopy 107, 227–231 (2007).
[Crossref]

Rodenburg, J. M.

F. Zhang, I. Peterson, J. Vila-Comamala, A. Diaz, F. Berenguer, R. Bean, B. Chen, A. Menzel, I. K. Robinson, and J. M. Rodenburg, “Translation position determination in ptychographic coherent diffraction imaging,” Opt. Express 21, 13592–13606 (2013).
[Crossref]

A. M. Maiden and J. M. Rodenburg, “An improved ptychographical phase retrieval algorithm for diffractive imaging,” Ultramicroscopy 109, 1256–1262 (2009).
[Crossref]

J. M. Rodenburg, “Ptychography and related diffractive imaging methods,” Adv. Imaging Electron Phys. 150, 87–184 (2008).
[Crossref]

J. M. Rodenburg and H. M. Faulkner, “A phase retrieval algorithm for shifting illumination,” Appl. Phys. Lett. 85, 4795–4797 (2004).
[Crossref]

Rogalski, A.

A. Rogalski, Infrared and Terahertz Detectors (CRC Press, 2018).

Romberg, J.

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

Rong, L.

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

L. Rong, C. Tang, D. Wang, B. Li, F. Tan, Y. Wang, and X. Shi, “Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography,” Opt. Express 27, 938–950 (2019).
[Crossref]

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015).
[Crossref]

L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
[Crossref]

L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
[Crossref]

Root, D. N.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Roux, J.-F.

Ruan, H.

R. Horstmeyer, H. Ruan, and C. Yang, “Guidestar-assisted wavefront-shaping methods for focusing light into biological tissue,” Nat. Photonics 9, 563–571 (2015).
[Crossref]

Rudych, P. D.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Rüggeberg, M.

P. Zolliker, M. Rüggeberg, L. Valzania, and E. Hack, “Extracting wood properties from structured THz spectra: birefringence and water content,” IEEE Trans. Terahertz Sci. Technol. 7, 722–731 (2017).
[Crossref]

Ryle, J. P.

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

Sai, P.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Sakhno, M.

M. Sakhno, A. Golenkov, and F. Sizov, “Uncooled detector challenges: millimeter-wave and terahertz long channel field effect transistor and Schottky barrier diode detectors,” J. Appl. Phys. 114, 164503 (2013).
[Crossref]

Sarahan, M.

A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012).
[Crossref]

Sasahara, T.

Sasaki, T.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Sasaki, Y.

Savinov, S. A.

O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

Sayre, D.

Scalari, G.

J. Faist, G. Scalari, M. Fischer, and M. Beck, “Terahertz quantum cascade lasers: 10 years of active region and material progresses,” in International Conference on Infrared, Millimeter, and Terahertz Waves (2011), pp. 1–2.

Scheglov, M.

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Schimmel, H.

Schmuttenmaer, C. A.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Schnars, U.

U. Schnars and W. Jueptner, Digital Holography: Digital Hologram Recording, Numerical Reconstruction, and Related Techniques (Springer, 2005).

Schulkin, B.

A. Redo-Sanchez, N. Laman, B. Schulkin, and T. Tongue, “Review of terahertz technology readiness assessment and applications,” J. Infrared Millim. Terahertz Waves 34, 500–518 (2013).
[Crossref]

Schumacher, P.

M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
[Crossref]

Seaberg, M. D.

Seeds, A.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Shah, Y.

Shalaby, M.

E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
[Crossref]

Shams, H.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Shanblatt, E. R.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

M. D. Seaberg, B. Zhang, D. F. Gardner, E. R. Shanblatt, M. M. Murnane, H. C. Kapteyn, and D. E. Adams, “Tabletop nanometer extreme ultraviolet imaging in an extended reflection mode using coherent Fresnel ptychography,” Optica 1, 39–44 (2014).
[Crossref]

Shen, C.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

Shen, C. L.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Shen, Y.

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

Sheridan, J. T.

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

Shevchenko, O.

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Shevchenko, O. A.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Shi, W.

X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.

Shi, X.

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

L. Rong, C. Tang, D. Wang, B. Li, F. Tan, Y. Wang, and X. Shi, “Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography,” Opt. Express 27, 938–950 (2019).
[Crossref]

Shichijo, H.

R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
[Crossref]

Shiktorov, P.

E. Starikov, P. Shiktorov, and V. Gruzinskis, “Physical mechanisms for terahertz generation,” in Ultrafast Phenomena in Semiconductors (1999), Vol. 297-2, 271–278.

Sibik, J.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Siemion, A.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Simoens, F.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

J. Oden, J. Meilhan, J. Lalanne-Dera, J.-F. Roux, F. Garet, J.-L. Coutaz, and F. Simoens, “Imaging of broadband terahertz beams using an array of antenna-coupled microbolometers operating at room temperature,” Opt. Express 21, 4817–4825 (2013).
[Crossref]

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Simon, A. C.

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

Sirtori, C.

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
[Crossref]

Sivco, D. L.

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
[Crossref]

Sizov, F.

F. Sizov, “Terahertz radiation detectors: the state-of-the-art,” Semicond. Sci. Technol. 33, 123001 (2018).
[Crossref]

M. Sakhno, A. Golenkov, and F. Sizov, “Uncooled detector challenges: millimeter-wave and terahertz long channel field effect transistor and Schottky barrier diode detectors,” J. Appl. Phys. 114, 164503 (2013).
[Crossref]

Skorobogatiy, M.

So, J.-K.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Solignac, P.

O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

Son, Y.-M.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

Starikov, E.

E. Starikov, P. Shiktorov, and V. Gruzinskis, “Physical mechanisms for terahertz generation,” in Ultrafast Phenomena in Semiconductors (1999), Vol. 297-2, 271–278.

Steiner, J. T.

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Stöhr, A.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Sudou, T.

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

Suga, M.

Suszek, J.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Sypek, M.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Taimre, T.

Takeda, M.

Takhar, D.

W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
[Crossref]

Tamminen, A.

A. Tamminen, J. Ala-Laurinaho, and A. V. Raisanen, “Indirect holographic imaging at 310 GHz,” in European Radar Conference (2008), pp. 168–171.

Tan, F.

Tang, C.

Tanksalvala, M.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

Taylor, Z. D.

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Temkin, R. J.

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Teppe, F.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Termkoa, K.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

Terroux, M.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

Thibault, P.

P. Thibault and A. Menzel, “Reconstructing state mixtures from diffraction measurements,” Nature 494, 68–71 (2013).
[Crossref]

P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009).
[Crossref]

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
[Crossref]

Thizy, C.

Thoman, A.

Thomas, B.

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Thurman, S. T.

Tian, L.

Titova, L. V.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Tomaszewski, D.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Tongue, T.

A. Redo-Sanchez, N. Laman, B. Schulkin, and T. Tongue, “Review of terahertz technology readiness assessment and applications,” J. Infrared Millim. Terahertz Waves 34, 500–518 (2013).
[Crossref]

Topart, P.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Tredicucci, A.

L. Mahler, A. Tredicucci, and M. S. Vitiello, “Quantum cascade laser: a compact, low cost, solid-state source for plasma diagnostics,” J. Instrum. 7, C02018 (2012).
[Crossref]

Tremblay, B.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

Treuttel, J.

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Trifutina, A. V.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Troccoli, M.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Tsai, E. H.

Tsui, Y. Y.

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

Tsurumachi, N.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Tsypkin, A. N.

N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016).
[Crossref]

Urbach, H.

P. Dwivedi, A. Konijnenberg, S. Pereira, and H. Urbach, “An alternative method to correct translation positions in ptychography,” Proc. SPIE 10677, 106772A (2018).
[Crossref]

Usov, I.

Vachon, C.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Valera, J.

T. Nguyen, J. Valera, and A. Moore, “Optical thickness measurement with multi-wavelength THz interferometry,” Opt. Lasers Eng. 61, 19–22 (2014).
[Crossref]

Valzania, L.

L. Valzania, P. Zolliker, and E. Hack, “Coherent reconstruction of a textile and a hidden object with terahertz radiation,” Optica 6, 518–523 (2019).
[Crossref]

L. Valzania, T. Feurer, P. Zolliker, and E. Hack, “Terahertz ptychography,” Opt. Lett. 43, 543–546 (2018).
[Crossref]

L. Valzania, E. Hack, P. Zolliker, R. Brönnimann, and T. Feurer, “Resolution limits of terahertz ptychography,” Proc. SPIE 10677, 1067720 (2018).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Topography of hidden objects using THz digital holography with multi-beam interferences,” Opt. Express 25, 11038–11047 (2017).
[Crossref]

P. Zolliker, M. Rüggeberg, L. Valzania, and E. Hack, “Extracting wood properties from structured THz spectra: birefringence and water content,” IEEE Trans. Terahertz Sci. Technol. 7, 722–731 (2017).
[Crossref]

E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Coherent terahertz imaging of a textile and a hidden object,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-2.

L. Valzania, Coherent Lensless Imaging Techniques Using Terahertz Radiation (University of Bern. Institute of Applied Physics, 2019).

Vandenrijt, J.-F.

I. Alexeenko, J.-F. Vandenrijt, G. Pedrini, C. Thizy, B. Vollheim, W. Osten, and M. P. Georges, “Nondestructive testing by using long-wave infrared interferometric techniques with CO2 lasers and microbolometer arrays,” Appl. Opt. 52, A56–A67 (2013).
[Crossref]

Y. Zhao, J.-F. Vandenrijt, M. Kirkove, and M. P. Georges, “Imaging quality and resolution enhancement by iterative phase retrieval in THz off-axis digital holography,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-3.

Vangala, S.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

Verreault, S.

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

Vijayraghavan, K.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Vila-Comamala, J.

Vinokurov, N.

M. Dem’yanenko, D. Esaev, V. Ovsyuk, B. Fomin, A. Aseev, B. Knyazev, G. Kulipanov, and N. Vinokurov, “Microbolometer detector arrays for the infrared and terahertz ranges,” J. Opt. Technol. 76, 739–743 (2009).
[Crossref]

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Vinokurov, N. A.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

Vitiello, M. S.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

L. Mahler, A. Tredicucci, and M. S. Vitiello, “Quantum cascade laser: a compact, low cost, solid-state source for plasma diagnostics,” J. Instrum. 7, C02018 (2012).
[Crossref]

Volkmann, K. V.

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Volkov, M. V.

N. V. Petrov, V. G. Bespalov, and M. V. Volkov, “Phase retrieval of THz radiation using set of 2D spatial intensity measurements with different wavelengths,” Proc. SPIE 8281, 82810J (2012).
[Crossref]

Vollheim, B.

Wakin, M. B.

E. J. Candès and M. B. Wakin, “An introduction to compressive sampling [a sensing/sampling paradigm that goes against the common knowledge in data acquisition],” IEEE Signal Process. Mag. 25(2), 21–30 (2008).
[Crossref]

Waldman, J.

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

Wallace, V. P.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Waller, L.

Walther, M.

Wan, M.

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

Wang, D.

L. Rong, C. Tang, D. Wang, B. Li, F. Tan, Y. Wang, and X. Shi, “Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography,” Opt. Express 27, 938–950 (2019).
[Crossref]

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

Z. Li, Q. Yan, Y. Qin, W. Kong, G. Li, M. Zou, D. Wang, Z. You, and X. Zhou, “Sparsity-based continuous-wave terahertz lens-free on-chip holography with sub-wavelength resolution,” Opt. Express 27, 702–713 (2019).
[Crossref]

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

Z. Li, L. Li, Y. Qin, G. Li, D. Wang, and X. Zhou, “Resolution and quality enhancement in terahertz in-line holography by sub-pixel sampling with double-distance reconstruction,” Opt. Express 24, 21134–21146 (2016).
[Crossref]

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015).
[Crossref]

L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
[Crossref]

L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
[Crossref]

Wang, H.

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

Wang, J.

J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019).
[Crossref]

Wang, L. J.

S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011).
[Crossref]

Wang, Q.

Wang, X.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

X. Wang, L. Hou, and Y. Zhang, “Continuous-wave terahertz interferometry with multiwavelength phase unwrapping,” Appl. Opt. 49, 5095–5102 (2010).
[Crossref]

Wang, X. J.

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

Wang, X. M.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Wang, Y.

L. Rong, C. Tang, D. Wang, B. Li, F. Tan, Y. Wang, and X. Shi, “Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography,” Opt. Express 27, 938–950 (2019).
[Crossref]

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015).
[Crossref]

L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
[Crossref]

Warr, I.

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

Wax, A.

P. Ferraro, A. Wax, and Z. Zalevsky, Coherent Light Microscopy: Imaging and Quantitative Phase Analysis (Springer, 2011), Vol. 46.

Weightman, P.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Whelan, P. R.

D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
[Crossref]

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

Wietzke, S.

R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
[Crossref]

Wikner, D. A.

Willenberg, H.

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

Williams, B. S.

B. S. Williams, “Terahertz quantum-cascade lasers,” Nat. Photonics 1, 517–525 (2007).
[Crossref]

Williams, G. P.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Withayachumnankul, W.

W. Withayachumnankul and M. Naftaly, “Fundamentals of measurement in terahertz time-domain spectroscopy,” J. Infrared Millim. Terahertz Waves 35, 610–637 (2014).
[Crossref]

Wolf, M.

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

Wu, C. Z.

Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
[Crossref]

Wu, W.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

Wu, W. D.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Wu, Y.

T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017).
[Crossref]

Wyrowski, F.

Xiao, T.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Xiao, W.

L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
[Crossref]

Xie, X.

X. Xie, J. M. Dai, and X. C. Zhang, “Coherent control of THz wave generation in ambient air,” Phys. Rev. Lett. 96, 075005 (2006).
[Crossref]

Xu, J.

X.-C. Zhang and J. Xu, Introduction to THz Wave Photonics (Springer, 2010).

Xu, M.

X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.

Xu, Y.

X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.

Xue, K.

Q. Li, S. Ding, Y. Li, K. Xue, and Q. Wang, “Experimental research on resolution improvement in CW THz digital holography,” Appl. Phys. B 107, 103–110 (2012).
[Crossref]

K. Xue, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz in-line digital holography,” Opt. Lett. 37, 3228–3230 (2012).
[Crossref]

Yahniuk, I.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Yamagiwa, M.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Yamamoto, H.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Yamashita, M.

Yan, Q.

Yang, C.

R. Horstmeyer, H. Ruan, and C. Yang, “Guidestar-assisted wavefront-shaping methods for focusing light into biological tissue,” Nat. Photonics 9, 563–571 (2015).
[Crossref]

Yang, N.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Yasui, T.

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

Yeh, L.-H.

You, Z.

Yu, Z.

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

Yuasa, T.

Zaborowski, M.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Zagrajek, P.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

Zalevsky, Z.

P. Ferraro, A. Wax, and Z. Zalevsky, Coherent Light Microscopy: Imaging and Quantitative Phase Analysis (Springer, 2011), Vol. 46.

Zeitler, A.

K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, Terahertz Spectroscopy and Imaging (Springer, 2012), Vol. 171.

Zeitler, J. A.

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

Zhan, Z.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

Zhan, Z. Q.

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Zhang, B.

Zhang, D.

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

Zhang, F.

Zhang, J.

J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019).
[Crossref]

J. Dai, J. Zhang, W. Zhang, and D. Grischkowsky, “Terahertz time-domain spectroscopy characterization of the far-infrared absorption and index of refraction of high-resistivity, float-zone silicon,” J. Opt. Soc. Am. B 21, 1379–1386 (2004).
[Crossref]

Zhang, M.

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

Zhang, W.

Zhang, X.

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

Zhang, X. C.

X. Xie, J. M. Dai, and X. C. Zhang, “Coherent control of THz wave generation in ambient air,” Phys. Rev. Lett. 96, 075005 (2006).
[Crossref]

Zhang, X.-C.

X.-C. Zhang and J. Xu, Introduction to THz Wave Photonics (Springer, 2010).

Zhang, Y.

Zhao, L.

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

Zhao, Y.

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

Y. Zhao, J.-F. Vandenrijt, M. Kirkove, and M. P. Georges, “Imaging quality and resolution enhancement by iterative phase retrieval in THz off-axis digital holography,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-3.

Zheng, H.

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

Zheng, Z.

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

Zhong, S.

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

Zhou, X.

Zhou, Y.

Zhou, Z.

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

Zidansek, A.

M. Jazbinsek, U. Puc, A. Abina, and A. Zidansek, “Organic crystals for THz photonics,” Appl. Sci. 9, 882 (2019).
[Crossref]

Zolliker, P.

L. Valzania, P. Zolliker, and E. Hack, “Coherent reconstruction of a textile and a hidden object with terahertz radiation,” Optica 6, 518–523 (2019).
[Crossref]

L. Valzania, T. Feurer, P. Zolliker, and E. Hack, “Terahertz ptychography,” Opt. Lett. 43, 543–546 (2018).
[Crossref]

L. Valzania, E. Hack, P. Zolliker, R. Brönnimann, and T. Feurer, “Resolution limits of terahertz ptychography,” Proc. SPIE 10677, 1067720 (2018).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Topography of hidden objects using THz digital holography with multi-beam interferences,” Opt. Express 25, 11038–11047 (2017).
[Crossref]

P. Zolliker, M. Rüggeberg, L. Valzania, and E. Hack, “Extracting wood properties from structured THz spectra: birefringence and water content,” IEEE Trans. Terahertz Sci. Technol. 7, 722–731 (2017).
[Crossref]

E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
[Crossref]

P. Zolliker and E. Hack, “THz holography in reflection using a high resolution microbolometer array,” Opt. Express 23, 10957–10967 (2015).
[Crossref]

E. Hack and P. Zolliker, “Terahertz holography for imaging amplitude and phase objects,” Opt. Express 22, 16079–16086 (2014).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Coherent terahertz imaging of a textile and a hidden object,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-2.

Zou, M.

Zou, R.

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

Zurutuza, A.

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

2D Mater. (1)

P. Bøggild, D. M. Mackenzie, P. R. Whelan, D. H. Petersen, J. D. Buron, A. Zurutuza, J. Gallop, L. Hao, and P. U. Jepsen, “Mapping the electrical properties of large-area graphene,” 2D Mater. 4, 042003 (2017).
[Crossref]

Acta Crystallogr. A (1)

W. Hoppe, “Diffraction in inhomogeneous primary wave fields. 1. Principle of phase determination from electron diffraction interference,” Acta Crystallogr. A 25, 495–501 (1969).
[Crossref]

Adv. Imaging Electron Phys. (1)

J. M. Rodenburg, “Ptychography and related diffractive imaging methods,” Adv. Imaging Electron Phys. 150, 87–184 (2008).
[Crossref]

Adv. Opt. Photon. (1)

AIP Adv. (1)

X. M. Wang, C. L. Shen, T. Jiang, Z. Q. Zhan, Q. H. Deng, W. H. Li, W. D. Wu, N. Yang, W. D. Chu, and S. Q. Duan, “High-power terahertz quantum cascade lasers with similar to 0.23 W in continuous-wave mode,” AIP Adv. 6, 075210 (2016).
[Crossref]

Appl. Opt. (12)

A. Dobroiu, M. Yamashita, Y. N. Ohshima, Y. Morita, C. Otani, and K. Kawase, “Terahertz imaging system based on a backward-wave oscillator,” Appl. Opt. 43, 5637–5646 (2004).
[Crossref]

S. Martens, B. Gompf, and M. Dressel, “Characterization of continuous-wave terahertz sources: laser mixing versus backward-wave oscillators,” Appl. Opt. 48, 5490–5496 (2009).
[Crossref]

J. R. Fienup, “Phase retrieval algorithms: a comparison,” Appl. Opt. 21, 2758–2769 (1982).
[Crossref]

H. Huang, L. Rong, D. Wang, W. Li, Q. Deng, B. Li, Y. Wang, Z. Zhan, X. Wang, and W. Wu, “Synthetic aperture in terahertz in-line digital holography for resolution enhancement,” Appl. Opt. 55, A43–A48 (2016).
[Crossref]

C. F. Cull, D. A. Wikner, J. N. Mait, M. Mattheiss, and D. J. Brady, “Millimeter-wave compressive holography,” Appl. Opt. 49, E67–E82 (2010).
[Crossref]

J. Hu, Q. Li, and S. Cui, “Research on object-plane constraints and hologram expansion in phase retrieval algorithms for continuous-wave terahertz inline digital holography reconstruction,” Appl. Opt. 53, 7112–7119 (2014).
[Crossref]

J. Hu, Q. Li, and Y. Zhou, “Support-domain constrained phase retrieval algorithms in terahertz in-line digital holography reconstruction of a nonisolated amplitude object,” Appl. Opt. 55, 379–386 (2016).
[Crossref]

K. Matsushima, “Formulation of the rotational transformation of wave fields and their application to digital holography,” Appl. Opt. 47, D110–D116 (2008).
[Crossref]

X. Wang, L. Hou, and Y. Zhang, “Continuous-wave terahertz interferometry with multiwavelength phase unwrapping,” Appl. Opt. 49, 5095–5102 (2010).
[Crossref]

G. Chen and Q. Li, “Markov chain Monte Carlo sampling based terahertz holography image denoising,” Appl. Opt. 54, 4345–4351 (2015).
[Crossref]

P. Almoro, G. Pedrini, and W. Osten, “Complete wavefront reconstruction using sequential intensity measurements of a volume speckle field,” Appl. Opt. 45, 8596–8605 (2006).
[Crossref]

I. Alexeenko, J.-F. Vandenrijt, G. Pedrini, C. Thizy, B. Vollheim, W. Osten, and M. P. Georges, “Nondestructive testing by using long-wave infrared interferometric techniques with CO2 lasers and microbolometer arrays,” Appl. Opt. 52, A56–A67 (2013).
[Crossref]

Appl. Phys. B (1)

Q. Li, S. Ding, Y. Li, K. Xue, and Q. Wang, “Experimental research on resolution improvement in CW THz digital holography,” Appl. Phys. B 107, 103–110 (2012).
[Crossref]

Appl. Phys. Lett. (5)

J. Bjarnason, T. Chan, A. Lee, M. Celis, and E. Brown, “Millimeter-wave, terahertz, and mid-infrared transmission through common clothing,” Appl. Phys. Lett. 85, 519–521 (2004).
[Crossref]

W. L. Chan, K. Charan, D. Takhar, K. F. Kelly, R. G. Baraniuk, and D. M. Mittleman, “A single-pixel terahertz imaging system based on compressed sensing,” Appl. Phys. Lett. 93, 121105 (2008).
[Crossref]

C. Fattinger and D. Grischkowsky, “Point source terahertz optics,” Appl. Phys. Lett. 53, 1480–1482 (1988).
[Crossref]

M. Rochat, L. Ajili, H. Willenberg, J. Faist, H. Beere, G. Davies, E. Linfield, and D. Ritchie, “Low-threshold terahertz quantum-cascade lasers,” Appl. Phys. Lett. 81, 1381–1383 (2002).
[Crossref]

J. M. Rodenburg and H. M. Faulkner, “A phase retrieval algorithm for shifting illumination,” Appl. Phys. Lett. 85, 4795–4797 (2004).
[Crossref]

Appl. Sci. (2)

F. Blanchard, J. E. Nkeck, D. Matte, R. Nechache, and D. G. Cooke, “A low-cost terahertz camera,” Appl. Sci. 9, 2531 (2019).

M. Jazbinsek, U. Puc, A. Abina, and A. Zidansek, “Organic crystals for THz photonics,” Appl. Sci. 9, 882 (2019).
[Crossref]

Biomed. Opt. Express (1)

C. R. Phys. (3)

H. Minamide and H. Ito, “Frequency-agile terahertz-wave generation and detection using a nonlinear optical conversion, and their applications for imaging,” C. R. Phys. 11, 457–471 (2010).
[Crossref]

A. Maestrini, B. Thomas, H. Wang, C. Jung, J. Treuttel, Y. Jin, G. Chattopadhyay, I. Mehdi, and G. Beaudin, “Schottky diode-based terahertz frequency multipliers and mixers,” C. R. Phys. 11, 480–495 (2010).
[Crossref]

N. Oda, “Uncooled bolometer-type terahertz focal plane array and camera for real-time imaging,” C. R. Phys. 11, 496–509 (2010).
[Crossref]

IEEE J. Sel. Top. Quantum Electron. (3)

Z. S. Gribnikov, R. R. Bashirov, and V. V. Mitin, “Negative effective mass mechanism of negative differential drift velocity and terahertz generation,” IEEE J. Sel. Top. Quantum Electron. 7, 630–640 (2001).
[Crossref]

S. Y. Jung, Y. F. Jiang, K. Vijayraghavan, A. T. Jiang, F. Demmerle, G. Boehm, X. J. Wang, M. Troccoli, M. C. Amann, and M. A. Belkin, “Recent progress in widely tunable single-mode room temperature terahertz quantum cascade laser sources,” IEEE J. Sel. Top. Quantum Electron. 21, 134–143 (2015).
[Crossref]

S. Kumar, “Recent progress in terahertz quantum cascade lasers,” IEEE J. Sel. Top. Quantum Electron. 17, 38–47 (2011).
[Crossref]

IEEE J. Solid-State Circuits (1)

R. Han, Y. Zhang, Y. Kim, D. Y. Kim, H. Shichijo, E. Afshari, and K. O. Kenneth, “Active terahertz imaging using Schottky diodes in CMOS: array and 860-GHz pixel,” IEEE J. Solid-State Circuits 48, 2296–2308 (2013).
[Crossref]

IEEE Signal Process. Mag. (1)

E. J. Candès and M. B. Wakin, “An introduction to compressive sampling [a sensing/sampling paradigm that goes against the common knowledge in data acquisition],” IEEE Signal Process. Mag. 25(2), 21–30 (2008).
[Crossref]

IEEE Trans. Antennas Propag. (2)

G. Hislop, L. Li, and A. Hellicar, “Phase retrieval for millimeter-and submillimeter-wave imaging,” IEEE Trans. Antennas Propag. 57, 286–290 (2009).
[Crossref]

G. Hislop, G. C. James, and A. Hellicar, “Phase retrieval of scattered fields,” IEEE Trans. Antennas Propag. 55, 2332–2341 (2007).
[Crossref]

IEEE Trans. Terahertz Sci. Technol. (6)

M. C. Kemp, “Explosives detection by terahertz spectroscopy—a bridge too far?” IEEE Trans. Terahertz Sci. Technol. 1, 282–292 (2011).
[Crossref]

M. S. Heimbeck, W. R. Ng, D. R. Golish, M. E. Gehm, and H. O. Everitt, “Terahertz digital holographic imaging of voids within visibly opaque dielectrics,” IEEE Trans. Terahertz Sci. Technol. 5, 110–116 (2015).
[Crossref]

Y. Y. Choporova, B. A. Knyazev, and M. S. Mitkov, “Classical holography in the terahertz range: recording and reconstruction techniques,” IEEE Trans. Terahertz Sci. Technol. 5, 836–844 (2015).
[Crossref]

N. V. Petrov, M. S. Kulya, A. N. Tsypkin, V. G. Bespalov, and A. Gorodetsky, “Application of terahertz pulse time-domain holography for phase imaging,” IEEE Trans. Terahertz Sci. Technol. 6, 464–472 (2016).
[Crossref]

P. Zolliker, M. Rüggeberg, L. Valzania, and E. Hack, “Extracting wood properties from structured THz spectra: birefringence and water content,” IEEE Trans. Terahertz Sci. Technol. 7, 722–731 (2017).
[Crossref]

J. H. Booske, R. J. Dobbs, C. D. Joye, C. L. Kory, G. R. Neil, G. S. Park, J. Park, and R. J. Temkin, “Vacuum electronic high power terahertz sources,” IEEE Trans. Terahertz Sci. Technol. 1, 54–75 (2011).
[Crossref]

Infrared Phys. Technol. (1)

J. Wang, J. Zhang, T. Chang, L. Liu, and H.-L. Cui, “Terahertz nondestructive imaging for foreign object detection in glass fibre-reinforced polymer composite panels,” Infrared Phys. Technol. 98, 36–44 (2019).
[Crossref]

Int. J. Infrared Millim. Waves (1)

R. Piesiewicz, C. Jansen, S. Wietzke, D. Mittleman, M. Koch, and T. Kürner, “Properties of building and plastic materials in the THz range,” Int. J. Infrared Millim. Waves 28, 363–371 (2007).
[Crossref]

Inverse Prob. (1)

R. Bamler and P. Hartl, “Synthetic aperture radar interferometry,” Inverse Prob. 14, R1–R54 (1998).
[Crossref]

J. Alloys Compd. (1)

T. Jiang, C. Shen, Z. Zhan, R. Zou, J. Li, L. Fan, T. Xiao, W. Li, Q. Hua Deng, L. Peng, X. Wang, and W. Wu, “Fabrication of 4.4 THz quantum cascade laser and its demonstration in high-resolution digital holographic imaging,” J. Alloys Compd. 771, 106–110 (2019).
[Crossref]

J. Appl. Phys. (2)

M. Sakhno, A. Golenkov, and F. Sizov, “Uncooled detector challenges: millimeter-wave and terahertz long channel field effect transistor and Schottky barrier diode detectors,” J. Appl. Phys. 114, 164503 (2013).
[Crossref]

S. Preu, G. H. Dohler, S. Malzer, L. J. Wang, and A. C. Gossard, “Tunable, continuous-wave terahertz photomixer sources and applications,” J. Appl. Phys. 109, 061301 (2011).
[Crossref]

J. Infrared Millim. Terahertz Waves (6)

A. Redo-Sanchez, N. Laman, B. Schulkin, and T. Tongue, “Review of terahertz technology readiness assessment and applications,” J. Infrared Millim. Terahertz Waves 34, 500–518 (2013).
[Crossref]

W. Withayachumnankul and M. Naftaly, “Fundamentals of measurement in terahertz time-domain spectroscopy,” J. Infrared Millim. Terahertz Waves 35, 610–637 (2014).
[Crossref]

J. P. Guillet, B. Recur, L. Frederique, B. Bousquet, L. Canioni, I. Manek-Hönninger, P. Desbarats, and P. Mounaix, “Review of terahertz tomography techniques,” J. Infrared Millim. Terahertz Waves 35, 382–411 (2014).
[Crossref]

N. Oda, S. Kurashina, M. Miyoshi, K. Doi, T. Ishi, T. Sudou, T. Morimoto, H. Goto, and T. Sasaki, “Microbolometer terahertz focal plane array and camera with improved sensitivity in the sub-terahertz region,” J. Infrared Millim. Terahertz Waves 36, 947–960 (2015).
[Crossref]

T. Bowman, Y. Wu, J. Gauch, L. K. Campbell, and M. El-Shenawee, “Terahertz imaging of three-dimensional dehydrated breast cancer tumors,” J. Infrared Millim. Terahertz Waves 38, 766–786 (2017).
[Crossref]

M. Yamagiwa, T. Ogawa, T. Minamikawa, D. G. Abdelsalam, K. Okabe, N. Tsurumachi, Y. Mizutani, T. Iwata, H. Yamamoto, and T. Yasui, “Real-time amplitude and phase imaging of optically opaque objects by combining full-field off-axis terahertz digital holography with angular spectrum reconstruction,” J. Infrared Millim. Terahertz Waves 39, 561–572 (2018).
[Crossref]

J. Infrared Millim. Terahertz Wavesc (1)

D. Dufour, L. Marchese, M. Terroux, H. Oulachgar, F. Généreux, M. Doucet, L. Mercier, B. Tremblay, C. Alain, P. Beaupré, N. Blanchard, M. Bolduc, C. Chevalier, D. D’Amato, Y. Desroches, F. Duchesne, L. Gagnon, S. Ilias, H. Jerominek, F. Lagacé, J. Lambert, F. Lamontagne, L. Le Noc, A. Martel, O. Pancrati, J.-E. Paultre, T. Pope, F. Provençal, P. Topart, C. Vachon, S. Verreault, and A. Bergeron,” Review of terahertz technology development at INO,” J. Infrared Millim. Terahertz Wavesc 36, 922–946 (2015).
[Crossref]

J. Instrum. (1)

L. Mahler, A. Tredicucci, and M. S. Vitiello, “Quantum cascade laser: a compact, low cost, solid-state source for plasma diagnostics,” J. Instrum. 7, C02018 (2012).
[Crossref]

J. Korean Phys. Soc. (2)

Y.-S. Jin, G.-J. Kim, and S.-G. Jeon, “Terahertz dielectric properties of polymers,” J. Korean Phys. Soc. 49, 513–517 (2006).

H. J. Cha, Y. U. Jeong, S. H. Park, B. C. Lee, and S. H. Park, “Power spectrum and coherence length measurements of a compact terahertz free-electron laser,” J. Korean Phys. Soc. 47, 798–802 (2005).

J. Opt. Soc. Am. (1)

J. Opt. Soc. Am. A (4)

J. Opt. Soc. Am. B (2)

J. Opt. Technol. (1)

J. Pharm. Sci. (1)

R. K. May, M. J. Evans, S. Zhong, I. Warr, L. F. Gladden, Y. Shen, and J. A. Zeitler, “Terahertz in-line sensor for direct coating thickness measurement of individual tablets during film coating in real-time,” J. Pharm. Sci. 100, 1535–1544 (2011).
[Crossref]

J. Phys. D (1)

S. S. Dhillon, M. S. Vitiello, E. H. Linfield, A. G. Davies, M. C. Hoffmann, J. Booske, C. Paoloni, M. Gensch, P. Weightman, G. P. Williams, E. Castro-Camus, D. R. S. Cumming, F. Simoens, I. Escorcia-Carranza, J. Grant, S. Lucyszyn, M. Kuwata-Gonokami, K. Konishi, M. Koch, C. A. Schmuttenmaer, T. L. Cocker, R. Huber, A. G. Markelz, Z. D. Taylor, V. P. Wallace, J. A. Zeitler, J. Sibik, T. M. Korter, B. Ellison, S. Rea, P. Goldsmith, K. B. Cooper, R. Appleby, D. Pardo, P. G. Huggard, V. Krozer, H. Shams, M. Fice, C. Renaud, A. Seeds, A. Stöhr, M. Naftaly, N. Ridler, R. Clarke, J. E. Cunningham, and M. B. Johnston, “The 2017 terahertz science and technology roadmap,” J. Phys. D 50, 043001 (2017).
[Crossref]

Nat. Commun. (2)

A. Redo-Sanchez, B. Heshmat, A. Aghasi, S. Naqvi, M. Zhang, J. Romberg, and R. Raskar, “Terahertz time-gated spectral imaging for content extraction through layered structures,” Nat. Commun. 7, 12665 (2016).
[Crossref]

Y. Jin, L. Gao, J. Chen, C. Z. Wu, J. L. Reno, and S. Kumar, “High power surface emitting terahertz laser with hybrid second- and fourth-order Bragg gratings,” Nat. Commun. 9, 1407 (2018).
[Crossref]

Nat. Photonics (6)

B. S. Williams, “Terahertz quantum-cascade lasers,” Nat. Photonics 1, 517–525 (2007).
[Crossref]

T. L. Cocker, V. Jelic, M. Gupta, S. J. Molesky, J. A. Burgess, G. De Los Reyes, L. V. Titova, Y. Y. Tsui, M. R. Freeman, and F. A. Hegmann, “An ultrafast terahertz scanning tunnelling microscope,” Nat. Photonics 7, 620–625 (2013).
[Crossref]

R. Horstmeyer, H. Ruan, and C. Yang, “Guidestar-assisted wavefront-shaping methods for focusing light into biological tissue,” Nat. Photonics 9, 563–571 (2015).
[Crossref]

A. P. Mosk, A. Lagendijk, G. Lerosey, and M. Fink, “Controlling waves in space and time for imaging and focusing in complex media,” Nat. Photonics 6, 283–292 (2012).
[Crossref]

F. Pfeiffer, “X-ray ptychography,” Nat. Photonics 12, 9–17 (2018).
[Crossref]

D. F. Gardner, M. Tanksalvala, E. R. Shanblatt, X. Zhang, B. R. Galloway, C. L. Porter, and R. Karl, C. Bevis, D. E. Adams, H. C. Kapteyn, M. M. Murnane, and G. F. Mancini, “Subwavelength coherent imaging of periodic samples using a 13.5 nm tabletop high-harmonic light source,” Nat. Photonics 11, 259–263 (2017).
[Crossref]

Nature (3)

P. Thibault and A. Menzel, “Reconstructing state mixtures from diffraction measurements,” Nature 494, 68–71 (2013).
[Crossref]

A. Crocker, H. A. Gebbie, M. F. Kimmitt, and L. E. S. Mathias, “Stimulated emission in the far infra-red,” Nature 201, 250–251 (1964).
[Crossref]

D. Gabor, “A new microscopic principle,” Nature 161, 777–778 (1948).
[Crossref]

Nucl. Instrum. Methods Phys. Res. A (2)

V. Cherkassky, B. Knyazev, V. Kubarev, G. Kulipanov, G. Kuryshev, A. Matveenko, A. Petrov, V. Popik, M. Scheglov, O. Shevchenko, and N. Vinokurov, “Imaging techniques for a high-power THz free electron laser,” Nucl. Instrum. Methods Phys. Res. A 543, 102–109 (2005).
[Crossref]

Y. U. Jeong, G. M. Kazakevitch, H. J. Cha, S. H. Park, and B. C. Lee, “Application of a wide-band compact FEL on THz imaging,” Nucl. Instrum. Methods Phys. Res. A 543, 90–95 (2005).
[Crossref]

Opt. Commun. (3)

R. J. Mahon, J. A. Murphy, and W. Lanigan, “Digital holography at millimetre wavelengths,” Opt. Commun. 260, 469–473 (2006).
[Crossref]

H. Huang, D. Wang, L. Rong, S. Panezai, D. Zhang, P. Qiu, L. Gao, H. Gao, H. Zheng, and Z. Zheng, “Continuous-wave off-axis and in-line terahertz digital holography with phase unwrapping and phase autofocusing,” Opt. Commun. 426, 612–622 (2018).
[Crossref]

H. Huang, D. Wang, L. Rong, X. Zhou, Z. Li, and Y. Wang, “Application of autofocusing methods in continuous-wave terahertz in-line digital holography,” Opt. Commun. 346, 93–98 (2015).
[Crossref]

Opt. Eng. (2)

D. Wang, Y. Zhao, L. Rong, M. Wan, X. Shi, Y. Wang, and J. T. Sheridan, “Expanding the field-of-view and profile measurement of covered objects in continuous-wave terahertz reflective digital holography,” Opt. Eng. 58, 023111 (2019).
[Crossref]

Q. Deng, W. Li, X. Wang, Z. Li, H. Huang, C. Shen, Z. Zhan, R. Zou, T. Jiang, and W. Wu, “High-resolution terahertz inline digital holography based on quantum cascade laser,” Opt. Eng. 56, 113102 (2017).
[Crossref]

Opt. Express (18)

L. Rong, T. Latychevskaia, D. Wang, X. Zhou, H. Huang, Z. Li, and Y. Wang, “Terahertz in-line digital holography of dragonfly hindwing: amplitude and phase reconstruction at enhanced resolution by extrapolation,” Opt. Express 22, 17236–17245 (2014).
[Crossref]

J. Oden, J. Meilhan, J. Lalanne-Dera, J.-F. Roux, F. Garet, J.-L. Coutaz, and F. Simoens, “Imaging of broadband terahertz beams using an array of antenna-coupled microbolometers operating at room temperature,” Opt. Express 21, 4817–4825 (2013).
[Crossref]

Z. Li, Q. Yan, Y. Qin, W. Kong, G. Li, M. Zou, D. Wang, Z. You, and X. Zhou, “Sparsity-based continuous-wave terahertz lens-free on-chip holography with sub-wavelength resolution,” Opt. Express 27, 702–713 (2019).
[Crossref]

E. Hack and P. Zolliker, “Terahertz holography for imaging amplitude and phase objects,” Opt. Express 22, 16079–16086 (2014).
[Crossref]

P. Zolliker and E. Hack, “THz holography in reflection using a high resolution microbolometer array,” Opt. Express 23, 10957–10967 (2015).
[Crossref]

M. S. Heimbeck, M. K. Kim, D. A. Gregory, and H. O. Everitt, “Terahertz digital holography using angular spectrum and dual wavelength reconstruction methods,” Opt. Express 19, 9192–9200 (2011).
[Crossref]

L. Rong, C. Tang, D. Wang, B. Li, F. Tan, Y. Wang, and X. Shi, “Probe position correction based on overlapped object wavefront cross-correlation for continuous-wave terahertz ptychography,” Opt. Express 27, 938–950 (2019).
[Crossref]

M. Humphreys, J. Grant, I. Escorcia-Carranza, C. Accarino, M. Kenney, Y. Shah, K. Rew, and D. Cumming, “Video-rate terahertz digital holographic imaging system,” Opt. Express 26, 25805–25813 (2018).
[Crossref]

Y. L. Lim, K. Bertling, T. Taimre, T. Gillespie, C. Glenn, A. Robinson, D. Indjin, Y. Han, L. Li, E. H. Linfield, A. G. Davies, P. Dean, and A. D. Rakić, “Coherent imaging using laser feedback interferometry with pulsed-mode terahertz quantum cascade lasers,” Opt. Express 27, 10221–10233 (2019).
[Crossref]

M. Suga, Y. Sasaki, T. Sasahara, T. Yuasa, and C. Otani, “THz phase-contrast computed tomography based on Mach-Zehnder interferometer using continuous-wave source: proof of the concept,” Opt. Express 21, 25389–25402 (2013).
[Crossref]

L. Valzania, P. Zolliker, and E. Hack, “Topography of hidden objects using THz digital holography with multi-beam interferences,” Opt. Express 25, 11038–11047 (2017).
[Crossref]

D. M. Mackenzie, P. R. Whelan, P. Bøggild, P. U. Jepsen, A. Redo-Sanchez, D. Etayo, N. Fabricius, and D. H. Petersen, “Quality assessment of terahertz time-domain spectroscopy transmission and reflection modes for graphene conductivity mapping,” Opt. Express 26, 9220–9229 (2018).
[Crossref]

A. Bitzer, H. Merbold, A. Thoman, T. Feurer, H. Helm, and M. Walther, “Terahertz near-field imaging of electric and magnetic resonances of a planar metamaterial,” Opt. Express 17, 3826–3834 (2009).
[Crossref]

D. M. Mittleman, “Twenty years of terahertz imaging,” Opt. Express 26, 9417–9431 (2018).
[Crossref]

Z. Li, L. Li, Y. Qin, G. Li, D. Wang, and X. Zhou, “Resolution and quality enhancement in terahertz in-line holography by sub-pixel sampling with double-distance reconstruction,” Opt. Express 24, 21134–21146 (2016).
[Crossref]

T. Latychevskaia and H.-W. Fink, “Resolution enhancement in digital holography by self-extrapolation of holograms,” Opt. Express 21, 7726–7733 (2013).
[Crossref]

E. H. Tsai, I. Usov, A. Diaz, A. Menzel, and M. Guizar-Sicairos, “X-ray ptychography with extended depth of field,” Opt. Express 24, 29089–29108 (2016).
[Crossref]

F. Zhang, I. Peterson, J. Vila-Comamala, A. Diaz, F. Berenguer, R. Bean, B. Chen, A. Menzel, I. K. Robinson, and J. M. Rodenburg, “Translation position determination in ptychographic coherent diffraction imaging,” Opt. Express 21, 13592–13606 (2013).
[Crossref]

Opt. Lasers Eng. (3)

H. Huang, D. Wang, W. Li, L. Rong, Z. D. Taylor, Q. Deng, B. Li, Y. Wang, W. Wu, and S. Panezai, “Continuous-wave terahertz multi-plane in-line digital holography,” Opt. Lasers Eng. 94, 76–81 (2017).
[Crossref]

L. Rong, Y. Li, S. Liu, W. Xiao, F. Pan, and D. Wang, “Iterative solution to twin image problem in in-line digital holography,” Opt. Lasers Eng. 51, 553–559 (2013).
[Crossref]

T. Nguyen, J. Valera, and A. Moore, “Optical thickness measurement with multi-wavelength THz interferometry,” Opt. Lasers Eng. 61, 19–22 (2014).
[Crossref]

Opt. Lett. (9)

K. Xue, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz in-line digital holography,” Opt. Lett. 37, 3228–3230 (2012).
[Crossref]

M. Guizar-Sicairos, S. T. Thurman, and J. R. Fienup, “Efficient subpixel image registration algorithms,” Opt. Lett. 33, 156–158 (2008).
[Crossref]

L. Valzania, T. Feurer, P. Zolliker, and E. Hack, “Terahertz ptychography,” Opt. Lett. 43, 543–546 (2018).
[Crossref]

B. N. Behnken, G. Karunasiri, D. R. Chamberlin, P. R. Robrish, and J. Faist, “Real-time imaging using a 2.8 THz quantum cascade laser and uncooled infrared microbolometer camera,” Opt. Lett. 33, 440–442 (2008).
[Crossref]

S.-H. Ding, Q. Li, Y.-D. Li, and Q. Wang, “Continuous-wave terahertz digital holography by use of a pyroelectric array camera,” Opt. Lett. 36, 1993–1995 (2011).
[Crossref]

É. Hérault, M. Hofman, F. Garet, and J.-L. Coutaz, “Observation of terahertz beam diffraction by fabrics,” Opt. Lett. 38, 2708–2710 (2013).
[Crossref]

M. Heimbeck, D. Marks, D. Brady, and H. Everitt, “Terahertz interferometric synthetic aperture tomography for confocal imaging systems,” Opt. Lett. 37, 1316–1318 (2012).
[Crossref]

W. L. Chan, M. L. Moravec, R. G. Baraniuk, and D. M. Mittleman, “Terahertz imaging with compressed sensing and phase retrieval,” Opt. Lett. 33, 974–976 (2008).
[Crossref]

G. Pedrini, W. Osten, and Y. Zhang, “Wave-front reconstruction from a sequence of interferograms recorded at different planes,” Opt. Lett. 30, 833–835 (2005).
[Crossref]

Opt. Mater. Express (1)

Optica (3)

Optik (1)

R. W. Gerchberg, “A practical algorithm for the determination of phase from image and diffraction plane pictures,” Optik 35, 237–246 (1972).

Phys. Rev. Lett. (4)

Y. He, P. I. Ku, J. Knab, J. Chen, and A. Markelz, “Protein dynamical transition does not require protein structure,” Phys. Rev. Lett. 101, 178103 (2008).
[Crossref]

S. Leinß, T. Kampfrath, K. V. Volkmann, M. Wolf, J. T. Steiner, M. Kira, S. W. Koch, A. Leitenstorfer, and R. Huber, “Terahertz coherent control of optically dark paraexcitons in Cu2O,” Phys. Rev. Lett. 101, 246401 (2008).
[Crossref]

X. Xie, J. M. Dai, and X. C. Zhang, “Coherent control of THz wave generation in ambient air,” Phys. Rev. Lett. 96, 075005 (2006).
[Crossref]

T. Latychevskaia and H.-W. Fink, “Solution to the twin image problem in holography,” Phys. Rev. Lett. 98, 233901 (2007).
[Crossref]

Phys. Scripta (1)

M. A. Belkin and F. Capasso, “New frontiers in quantum cascade lasers: high performance room temperature terahertz sources,” Phys. Scripta 90, 118002 (2015).
[Crossref]

Proc. IEEE (1)

M. Naftaly and R. E. Miles, “Terahertz time-domain spectroscopy for material characterization,” Proc. IEEE 95, 1658–1665 (2007).
[Crossref]

Proc. SPIE (12)

A. J. Gatesman, A. Danylov, T. M. Goyette, J. C. Dickinson, R. H. Giles, W. Goodhue, J. Waldman, W. E. Nixon, and W. Hoen, “Terahertz behavior of optical components and common materials,” Proc. SPIE 6212, 62120E (2006).
[Crossref]

F. Simoens, J. Meilhan, S. Gidon, G. Lasfargues, J. L. Dera, J. L. Ouvrier-Buffet, S. Pocas, W. Rabaud, F. Guellec, B. Dupont, S. Martin, and A. C. Simon, “Antenna-coupled microbolometer based uncooled 2D array and camera for 2D real-time terahertz imaging,” Proc. SPIE 8846, 88460O (2013).
[Crossref]

M. Wan, I. Muniraj, R. Malallah, L. Zhao, J. P. Ryle, L. Rong, J. J. Healy, D. Wang, and J. T. Sheridan, “Sparsity based terahertz reflective off-axis digital holography,” Proc. SPIE 10233, 102330T (2017).
[Crossref]

B. N. Behnken, M. Lowe, G. Karunasiri, D. Chamberlain, P. Robrish, and J. Faist, “Detection of 3.4 THz radiation from a quantum cascade laser using a microbolometer infrared camera,” Proc. SPIE 6549, 65490C (2007).
[Crossref]

L. Le Noc, B. Tremblay, A. Martel, C. Chevalier, N. Blanchard, M. Morissette, L. Mercier, F. Duchesne, L. Gagnon, P. Couture, F. Lévesque, N. Desnoyers, M. Demers, F. Lamontage, H. Jerominek, and A. Bergeron, “1280 × 960 pixel microscanned infrared imaging module,” Proc. SPIE 7660, 766021 (2010).
[Crossref]

A. A. Danylov, T. M. Goyette, J. Waldman, M. J. Coulombe, A. J. Gatesman, R. H. Giles, X. F. Qian, N. Chandrayan, S. Vangala, K. Termkoa, W. D. Goodhue, and W. E. Nixon, “Coherent imaging at 2.4 THz with a CW quantum cascade laser transmitter,” Proc. SPIE 7601, 760105 (2010).
[Crossref]

D. Fast, W. Hurlbut, and V. G. Kozlov, “Extending spectral coverage of BWOs combined with frequency multipliers to 2.6 THz,” Proc. SPIE 8261, 82610L (2012).
[Crossref]

N. V. Petrov, V. G. Bespalov, and M. V. Volkov, “Phase retrieval of THz radiation using set of 2D spatial intensity measurements with different wavelengths,” Proc. SPIE 8281, 82810J (2012).
[Crossref]

N. V. Petrov, A. N. Galiaskarov, T. Y. Nikolaeva, and V. G. Bespalov, “The features of optimization of a phase retrieval technique in THz frequency range,” Proc. SPIE 8413, 84131T (2012).
[Crossref]

L. E. Marchese, M. Terroux, D. Dufour, M. Bolduc, C. Chevalier, F. Généreux, H. Jerominek, and A. Bergeron, “Case study of concealed weapons detection at stand-off distances using a compact, large field-of-view THz camera,” Proc. SPIE 9083, 90832G (2014).
[Crossref]

L. Valzania, E. Hack, P. Zolliker, R. Brönnimann, and T. Feurer, “Resolution limits of terahertz ptychography,” Proc. SPIE 10677, 1067720 (2018).
[Crossref]

P. Dwivedi, A. Konijnenberg, S. Pereira, and H. Urbach, “An alternative method to correct translation positions in ptychography,” Proc. SPIE 10677, 106772A (2018).
[Crossref]

Sci. Rep. (2)

M. Locatelli, M. Ravaro, S. Bartalini, L. Consolino, M. S. Vitiello, R. Cicchi, F. Pavone, and P. De Natale, “Real-time terahertz digital holography with a quantum cascade laser,” Sci. Rep. 5, 13566 (2015).
[Crossref]

L. Rong, T. Latychevskaia, C. Chen, D. Wang, Z. Yu, X. Zhou, Z. Li, H. Huang, Y. Wang, and Z. Zhou, “Terahertz in-line digital holography of human hepatocellular carcinoma tissue,” Sci. Rep. 5, 8445 (2015).
[Crossref]

Science (2)

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994).
[Crossref]

P. Thibault, M. Dierolf, A. Menzel, O. Bunk, C. David, and F. Pfeiffer, “High-resolution scanning x-ray diffraction microscopy,” Science 321, 379–382 (2008).
[Crossref]

Semicond. Sci. Technol. (1)

F. Sizov, “Terahertz radiation detectors: the state-of-the-art,” Semicond. Sci. Technol. 33, 123001 (2018).
[Crossref]

Sensors (1)

E. Hack, L. Valzania, G. Gäumann, M. Shalaby, C. P. Hauri, and P. Zolliker, “Comparison of thermal detector arrays for off-axis THz holography and real-time THz imaging,” Sensors 16, 221 (2016).
[Crossref]

Ultramicroscopy (5)

J. Rodenburg, A. Hurst, and A. Cullis, “Transmission microscopy without lenses for objects of unlimited size,” Ultramicroscopy 107, 227–231 (2007).
[Crossref]

P. Thibault, M. Dierolf, O. Bunk, A. Menzel, and F. Pfeiffer, “Probe retrieval in ptychographic coherent diffractive imaging,” Ultramicroscopy 109, 338–343 (2009).
[Crossref]

A. M. Maiden and J. M. Rodenburg, “An improved ptychographical phase retrieval algorithm for diffractive imaging,” Ultramicroscopy 109, 1256–1262 (2009).
[Crossref]

A. Maiden, M. Humphry, M. Sarahan, B. Kraus, and J. Rodenburg, “An annealing algorithm to correct positioning errors in ptychography,” Ultramicroscopy 120, 64–72 (2012).
[Crossref]

O. Bunk, M. Dierolf, S. Kynde, I. Johnson, O. Marti, and F. Pfeiffer, “Influence of the overlap parameter on the convergence of the ptychographical iterative engine,” Ultramicroscopy 108, 481–487 (2008).
[Crossref]

Wood Sci. Technol. (1)

M. Koch, S. Hunsche, P. Schumacher, M. Nuss, J. Feldmann, and J. Fromm, “THz-imaging: a new method for density mapping of wood,” Wood Sci. Technol. 32, 421–427 (1998).
[Crossref]

Other (32)

M. C. Nuss and J. Orenstein, “Terahertz time-domain spectroscopy,” in Millimeter and Submillimeter Wave Spectroscopy of Solids (Springer, 1998), pp. 7–50.

G. P. Gallerano and S. Biedron, “Overview of terahertz radiation sources,” in Proceedings of the Free Electron Laser Conference (FEL) (2004), Vol. 1, pp. 216–221.

J. R. Freeman, H. E. Beere, and D. A. Ritchie, “Generation and detection of terahertz radiation,” in Terahertz Spectroscopy and Imaging, K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, eds. (Springer, 2012), pp. 1–28.

T. Kreis, Handbook of Holographic Interferometry: Optical and Digital Methods (Wiley, 2006).

K.-E. Peiponen, A. Zeitler, and M. Kuwata-Gonokami, Terahertz Spectroscopy and Imaging (Springer, 2012), Vol. 171.

M. Guizar-Sicairos, Methods for Coherent Lensless Imaging and X-Ray Wavefront Measurement (University of Rochester, 2010).

A. Rogalski, Infrared and Terahertz Detectors (CRC Press, 2018).

M. Naftaly, Terahertz Metrology (Artech House, 2015).

X.-C. Zhang and J. Xu, Introduction to THz Wave Photonics (Springer, 2010).

I. Park, “Investigations of the generation of tunable continuous-wave terahertz radiation and its spectroscopic applications,” Ph. D. thesis (Technische Universität Darmstadt, 2007).

J. Faist, G. Scalari, M. Fischer, and M. Beck, “Terahertz quantum cascade lasers: 10 years of active region and material progresses,” in International Conference on Infrared, Millimeter, and Terahertz Waves (2011), pp. 1–2.

O. A. Klimenko, Y. A. Mityagin, S. A. Savinov, V. N. Murzin, N. V. Dyakonova, P. Solignac, and W. Knap, “Terahertz wide range tunable cyclotron resonance p-Ge laser,” 16th International Conference on Electron Dynamics in Semiconductors, Optoelectronics and Nanostructures (Edison 16) (2009), Vol. 193.

E. Starikov, P. Shiktorov, and V. Gruzinskis, “Physical mechanisms for terahertz generation,” in Ultrafast Phenomena in Semiconductors (1999), Vol. 297-2, 271–278.

C.-W. Baik, Y.-M. Son, S. I. Kim, S. C. Jun, J.-S. Kim, J. Hwang, J.-M. Kim, S.-W. Moon, H. J. Kim, J.-K. So, and P. Gun-Sik, “Microfabricated coupled-cavity backward-wave oscillator for terahertz imaging,” in IEEE International Vacuum Electronics Conference (2008), pp. 398–399.

V. S. Cherkassky, B. A. Knyazev, S. V. Kozlov, V. V. Kubarev, G. N. Kulipanov, A. N. Matveenko, V. M. Popik, D. N. Root, P. D. Rudych, O. A. Shevchenko, A. V. Trifutina, and N. A. Vinokurov, “Terahertz imaging and holography with a high-power free electron laser,” in Joint 30th International Conference on Infrared and Millimeter Waves and 13th International Conference on Terahertz Electronics (2005), Vol. 2, pp. 337–338.

U. Schnars and W. Jueptner, Digital Holography: Digital Hologram Recording, Numerical Reconstruction, and Related Techniques (Springer, 2005).

P. Picart, New Techniques in Digital Holography (Wiley, 2015).

P. Ferraro, A. Wax, and Z. Zalevsky, Coherent Light Microscopy: Imaging and Quantitative Phase Analysis (Springer, 2011), Vol. 46.

P. K. Rastogi and E. Hack, Optical Methods for Solid Mechanics: A Full-Field Approach (Wiley, 2012).

L. Valzania, Coherent Lensless Imaging Techniques Using Terahertz Radiation (University of Bern. Institute of Applied Physics, 2019).

R. Mahon, A. Murphy, and W. Lanigan, “Terahertz holographic image reconstruction and analysis,” in Infrared and Millimeter Waves, Conference Digest of the 2004 Joint 29th International Conference and 12th International Conference on Terahertz Electronics (IEEE, 2004), pp. 749–750.

Y. Zhao, J.-F. Vandenrijt, M. Kirkove, and M. P. Georges, “Imaging quality and resolution enhancement by iterative phase retrieval in THz off-axis digital holography,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-3.

J. W. Goodman, Introduction to Fourier Optics (Roberts and Company, 2005).

X. Han, W. Shi, L. Hou, M. Xu, H. Liu, and Y. Xu, “Terahertz off-axis digital holography,” in 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz) (2016), pp. 1–2.

A. Tamminen, J. Ala-Laurinaho, and A. V. Raisanen, “Indirect holographic imaging at 310 GHz,” in European Radar Conference (2008), pp. 168–171.

M. Georges, “Long-wave infrared digital holography,” in New Techniques in Digital Holography (2015), pp. 219–254.

“Ophir THz laser measurement products,” 2019, https://bit.ly/2xW12Ex .

B. Knyazev, M. Dem’yanenko, and D. Esaev, “Terahertz imaging with a 160 × 120 pixel microbolometer 90-fps camera,” in Joint 32nd International Conference on Infrared and Millimeter Waves and the 15th International Conference on Terahertz Electronics (IEEE, 2007), pp. 360–361.

W. Knap and M. Dyakonov, “Field effect transistors for terahertz applications,” in Handbook of Terahertz Technology for Imaging, Sensing and Communications (Elsevier, 2013), pp. 121–155.

N. Dyakonova, D. Coquillat, F. Teppe, W. Knap, J. Suszek, A. Siemion, M. Sypek, D. B. But, P. Sai, I. Yahniuk, G. Cywinski, J. Marczewski, M. Zaborowski, D. Tomaszewski, and P. Zagrajek, “Terahertz vision using field effect transistors detectors arrays,” in 22nd International Microwave and Radar Conference (MIKON) (2018), pp. 711–714.

“Terasense imaging products,” 2019, https://bit.ly/2GDqd4A .

L. Valzania, P. Zolliker, and E. Hack, “Coherent terahertz imaging of a textile and a hidden object,” in Digital Holography and Three-Dimensional Imaging (Optical Society of America, 2019), paper Th4B-2.

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Figures (10)

Fig. 1.
Fig. 1. Schematic of off-axis digital holography (simulations). (a) Experimental setup; (b) hologram and (c) modulus of its Fourier transform; (d) amplitude and (e) phase of the reconstructed object function. The inset of (a) shows the average wavevectors of the object beam and reference beam, as well as their difference. Wavelength: 96.5 µm. Scale bars in (b), (d), and (e): 2 mm; scale bar in (c): $ 5{\text{mm}^{ - 1}} $ . Adapted with permission from [136].
Fig. 2.
Fig. 2. THz off-axis digital holographic reconstructions in reflection mode of an object moving at 5 mm/s. (a) Photograph of the object, a metallic plate with inscriptions; (b) reconstructed amplitude of the object at one position during its movement; (c) photograph of the plate covered by an optically opaque mask; (d) reconstructed amplitude of the hidden object at the same position as in (b). Scale bars: 4 mm. Adapted from [85] under the terms of the Creative Commons Attribution 4.0 License.
Fig. 3.
Fig. 3. Schematic of in-line digital holography (simulations). (a) Experimental setup; (b) simulated phase object and (c) corresponding hologram; (d) reconstruction where the (d) real [(e) twin] image is brought to focus. In (e), the complex conjugate of the reconstruction is shown, to favor its comparison with (d). Wavelength: 96.5 µm. Scale bars: 2 mm.
Fig. 4.
Fig. 4. THz in-line digital holographic reconstructions. (a) Photograph of the object, a human hepatocellular carcinoma tissue; (b) reconstructed absorption and (c) phase shift from a single $ 12.4 \times 12.4\,\,{\text{mm}^2} $ hologram; (d) reconstructed absorption and (e) phase shift from a larger hologram obtained through aperture synthesis; (f) reconstructed absorption and (g) phase shift after numerically extrapolating the holograms used for reconstructions (d) and (e). The green arrow indicates a cut across a vessel or a region damaged after freezing the object. The blue arrow indicates a vertical line that is a sign of tissue fibrosis, which can be resolved only in (g). Adapted from [108] under the terms of the Creative Commons Attribution 4.0 License.
Fig. 5.
Fig. 5. Steps of a typical phase retrieval technique, using three diffraction patterns recorded at different distances from the object (simulations). Wavelength: 96.5 µm. Scale bars: 2 mm.
Fig. 6.
Fig. 6. Two-intensity phase retrieval. (a) Schematic experimental setup, featuring: a BWO (A) with its waveguide opening (B), a chopper (C), a beam splitter made of non-conducting silicon (D), a detector to monitor the stability of the source (E), a beam stopper to prevent the THz radiation emitted by the source from directly reaching the receiver (F), mirrors (G), (H), a metallic thumbtack used as the object (I), and the receiver (J) moved longitudinally through two sliding blocks (K), (L) and transversely through a 2D stage (M). (b) Amplitude of the reconstructed object and (c) phase of the object and of the incident beam. Adapted with permission from [120] 2019 IEEE.