Accepted papers to appear in an upcoming issue
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Compensation method for thermal induced phase mismatching within a broad spectral range for second harmonic generation
Xun LIU, xue shen, Jianling Yin, and Xiaoming Li
Doc ID: 275135 Received 02 Sep 2016; Accepted 08 Dec 2016; Posted 08 Dec 2016 View: PDF
Abstract: A thermal induced phase mismatching compensation method which is capable for temperature-insensitive second harmonic generation within a broad spectral range is proposed. In the method, three nonlinear crystals are cascaded to act as a crystal combination. The crystals at two sides of the combination work for energy conversion, and the remained one, with opposite sign of the first temperature derivation of phase mismatching, is employed to compensate thermal induced phase mismatching in the first crystal. We theoretically demonstrate that the proposed method can be used to extend the temperature acceptance bandwidth for second harmonic generation in a broad spectral range. And two application examples, frequency conversion from 1064nm to 532nm with type II phase matching and 532nm to 266nm with type I phase matching, are studied. The numerical simulation results under undepeleted pump approximation show that the temperature acceptance bandwidth of the crystal combination is twice as wide as that of single crystal with the same length.
Generation of High Power Short Terahertz Pulses using Chirped Aperiodically Poled Structures
Alireza Yahaghi, Koustuban Ravi, Arya Fallahi, and Franz Kaertner
Doc ID: 279975 Received 03 Nov 2016; Accepted 07 Dec 2016; Posted 07 Dec 2016 View: PDF
Abstract: We introduce a collinear scheme for the highly efficient generation of broadband, single or few-cycle high power terahertz (THz) pulses using optical rectification. For this purpose, two concepts are introduced and thoroughly analyzed. The first concept is the generation of chirped broadband terahertz pulses using chirped aperiodically poled electro optic crystals. The second concept involves the compression of the terahertz pulses extracted from the aperiodically poled structure using a chirped mirror. An illustrative design employing cryogenically cooled aperiodically poled lithium niobate (APPLN) crystals and appropriate chirped mirrors ispresented. It is shown that the the presented design allows the optical pulse to be re-used in subsequent generation stages, resulting in optical-to-THz conversion efficiencies in excess of 5% for terahertz radiation centered around 0.3 THz. Analytic solutions and numerical calculations are presented. In order to design a crystal with optimum conversion efficiency, we take advantage of binary optimization techniques. This work paves the way for the generation of broadband terahertz radiation with several mJ of pulse energy using large area aperiodically poled structures.
Experimental Measurement and Analytical Estimation of Signal Gain in Er-doped Fiber
Olga Shtyrina, Aleksey Ivanenko, Irina Yarutkina, Anna Kemmer, Anton Skidin, Sergey Kobtsev, and Mikhail Fedoruk
Doc ID: 274768 Received 19 Sep 2016; Accepted 06 Dec 2016; Posted 06 Dec 2016 View: PDF
Abstract: We propose the theoretical method to estimate the saturation power and the small signal gain of an active Er-doped fiber as functions of the fiber length and the pump power. The results make possible to carry out the numerical simulation of a given Er-doped fiber. The results allow to carry out the optimization of fiber laser systems by means of numerical simulation using the nonlinear Schrodinger equation.
Parity breaking with a nonlinear optical double-slit configuration
Nikolaos Efremidis and Vassilis Paltoglou
Doc ID: 278676 Received 14 Oct 2016; Accepted 06 Dec 2016; Posted 06 Dec 2016 View: PDF
Abstract: We consider an optical nonlinear interferometric setup based on Young's double-slit configuration where a nonlinear material is placed exactly after one of the two slits. We examine the effects of Kerr nonlinearity and multi-photon absorption in the resulting interference pattern. The presence of nonlinearity breaks the transverse spatial symmetry of the system, resulting to a modified intensity pattern at the observation plane as a function of the incident intensity. Our theoretical model, based on the modification of the optical path due to the presence of nonlinearity, is surprisingly accurate in predicting the intensity profile of the main lobes for a wide range of parameters. We discuss about potential applications of our model in nonlinear interferometry. Specifically, we show that it is possible to measure both the multi-photon and the Kerr coefficients of a nonlinear material based on the spatial translation of the interference pattern as a function of the incident intensity.
Polarization grating fabricated by recording of vector hologram between two orthogonally polarized vector vortex beams
Moritsugu Sakamoto, Yuki Nakamoto, Kotaro Kawai, Kohei Noda, Tomoyuki Sasaki, Nobuhiro Kawatsuki, and Hiroshi Ono
Doc ID: 279122 Received 21 Oct 2016; Accepted 06 Dec 2016; Posted 06 Dec 2016 View: PDF
Abstract: Polarization gratings (PGs) were fabricated by the recording of vector holograms between two orthogonally polarized vector vortex beams (VVBs). The polarization and diffraction properties of the resulting PGs were analyzed theoretically. The feasibility of the process was demonstrated experimentally using a photo-crosslinkable liquid crystal polymer film as the polarization recording material. The fabricated PGs can convert homogeneously polarized laser beams into VVBs, vector beams, optical vortices, and ring-shaped optical lattices by controlling the incident beam's state of polarization (SOP). The PGs that are presented will be applicable to optical communications and optical manipulation processes as vortex generators and converters.
Laser power, cell temperature and beam quality dependence on cell length of static Cs DPAL
Boris Barmashenko, Karol Waichman, and Salman Rosenwaks
Doc ID: 279667 Received 28 Oct 2016; Accepted 06 Dec 2016; Posted 07 Dec 2016 View: PDF
Abstract: The influence of the cell length of a static diode-pumped Cs laser on the laser power, gain medium temperature and laser beam quality is studied theoretically using a three-dimensional, time-dependent computational fluid dynamics model where Gaussian spatial shapes of the pump and laser intensities in any cross section of the beams are assumed. Reasonable agreement with power measurements in a static diode-pumped alkali laser (DPAL) with 20 mm cell length [B.V. Zhdanov, J. Sell and R.J. Knize, Electron. Lett. 44 (2008) 582] is obtained. It is shown that the gain medium temperature rise caused by the pump beam absorption can be decreased by increasing the length of the alkali cell and that for given conditions there is an optimal cell length corresponding to maximum laser power. At ~100 W pump power the optimum cell length of ~50-60 mm is larger than the 20 mm length usually used in DPAL experiments. The increase of the cell length from 20 to 60 mm results in decrease of the gain medium temperature by 100-150 °K making it possible to avoid degradation of the laser power due to chemical reactions in the gain medium. Laser beam quality in terms of Strehl ratio was calculated as a function of pump power and length of the DPAL cell and found to decrease as the DPAL cell length is increased. It is shown that the wave front corrections result in substantial increase of the Strehl ratio and hence in improvement of the laser beam quality.
Connected hidden singularities and towards successive state flipping in degenerate optical microcavities
Somnath Ghosh and Arnab laha
Doc ID: 276012 Received 16 Sep 2016; Accepted 05 Dec 2016; Posted 06 Dec 2016 View: PDF
Abstract: Using scattering matrix (S-matrix) formalism, we report the formation of a special hidden singular line connecting multiple second order hidden singular points, in a non-uniformly pumped degenerate optical microcavity. Such singularities are known as exceptional points (EPs), and the line is proposed as exceptional line. Exploring the unconventional behavior of cavity resonances created by spatially imbalanced gain-loss profile, we have established the adiabatic state flipping mechanism of coupled resonances encountering such EPs. Various interesting encircling situations, incorporating smooth as well as fluctuating variations of the control parameters have been analyzed. We exploit the above scheme for the first time to analyze the optical performance and stability of cascaded flip-of-state phenomenon assisted by successive encirclement of either single or multiple singularities following the exceptional line in the context of optical mode converters.
X-Band SAR Imaging with a Liquid-Crystal Based Dynamic Metasurface Antenna
Claire Watts, Andreas Pedross-Engel, David Smith, and Matt Reynolds
Doc ID: 277676 Received 05 Oct 2016; Accepted 05 Dec 2016; Posted 06 Dec 2016 View: PDF
Abstract: Synthetic aperture radar (SAR) synthesizes a large effective aperture via coherent processing of multiple measurements taken from a moving platform. We present an approach for SAR imaging using an X-band dynamic metasurface antenna (MSA). This newly-developed antenna has over 6,000 liquid-crystal switched radiating elements that cover a circular area with an approximate diameter of 0.45 m. The MSA's main beam can be steered electronically to spherical angles of up to +/- 70 degrees. We present the first reported laboratory-scale imaging experiments with a liquid-crystal switched MSA. We leverage the beam steering capabilities of the MSA in a spotlight SAR mode to achieve a measured cross-range resolution of 1.6 cm, a 62% improvement over the 4.2 cm cross-range resolution achieved with the same aperture without the metasurface-enabled beam steering. The dynamic MSA offers the superior image resolution of a beam steering device without the hardware burden that usually comes with this capability.
Polarization dependence of graphene transient optical response: interplay between incident direction and anisotropic distribution of nonequilibrium carriers
Xiao-Qing Yan, Fang Liu, Jun Yao, Xiang-Tian Kong, Xin Zhao, Zhi-Bo Liu, and Jian-Guo Tian
Doc ID: 279408 Received 24 Oct 2016; Accepted 04 Dec 2016; Posted 05 Dec 2016 View: PDF
Abstract: The transient optical properties of graphene on a dielectric substrate rely on both the incident direction of light and anisotropic distribution of excited carriers in graphene. Here we study theoretically and experimentally the polarization dependence of transient optical reflection and transmission that caused by the interplay between the two factors. The interplay between the two factors results in the diverse polarization dependence characteristic and could shift the converting incident angle for inverse polarization dependence in transient optical response. At large incident angle, transient optical transmission is with more pronounced polarization dependence and without sign reversing, as compared with transient optical reflection. Our findings provide a basis for better management of graphene transient optical response in high-speed photonics devices.
Self Group-Velocity Modulation and AM-to-PM Conversion in Optical Rectification
Brian Kolner and Lanbing Kang
Doc ID: 276055 Received 19 Sep 2016; Accepted 03 Dec 2016; Posted 06 Dec 2016 View: PDF
Abstract: Optical rectification as a detection technique does not suffer fromthe nonlinearity, saturation and large AM-to-PM conversion effectsexhibited by semiconductor carrier-based photodiodes. In this paper weanalyze the effect of self group-velocity modulation (SGM) as amechanism for AM-to-PM conversion in traveling-wave opticalrectification detectors and derive a closed-form expression for theAM-to-PM conversion gain. For a small signal amplitude modulationindex m, we find the induced phase modulation index β_i on thenonlinear polarization wave due to a train of femtosecond opticalpulses in a bulk LiNbO₃ traveling-wave optical rectificationdetector to be β_i<3 × 10^(-8) m or β_i /m approximately -151dB. Cascaded χ^(2) processes as well as the thermo-optic effectare also considered with the former producing conversion gaincomparable to direct χ^(3) while the latter is four orders ofmagnitude smaller.
Numerical modelling of ultra-compact folded photonic crystal waveguide Mach-Zehnder interferometer thermo-optic switch
Din Chai Tee, Nizam Tamchek, Raymond Ooi, and Faisal Rafiq Mahamd Adikan
Doc ID: 277585 Received 26 Sep 2016; Accepted 30 Nov 2016; Posted 01 Dec 2016 View: PDF
Abstract: We numerically studied ultra-compact folded-path photonic crystal waveguide Mach-Zehnder interferometer (MZI) thermo-optic switch based on small bend radius double 180° waveguide bends MZI arm. The design can at least double the active waveguide length and sensitivity while maintaining a small heater size compared to the conventional MZI design. From 3-D Finite Difference Time Domain simulation, a refractive index increase of 0.019 in the 25µm long heated arm which is induced by a temperature difference of 102K produces a π phase shift in the output of the MZI.
Quantum-Mechanical Fingerprints in Generation of Elliptical Terahertz Radiation by Extended Media Interacting with Two-Color Laser Field
Sergey Stremoukhov and Anatoli Andreev
Doc ID: 275233 Received 02 Sep 2016; Accepted 29 Nov 2016; Posted 01 Dec 2016 View: PDF
Abstract: We present the results of the numerical study of the generation of the elliptical terahertz (THz) radiation by an extended argon gas media interacting with a two-color laser field. On the base of a single atom response to the action of the two-color laser field with a linear polarization of each of the components of the laser field and different angles between them, two angles (90º and 45º) and radiation at two frequencies (56 THz and 29 THz) corresponding to them and having relatively high values of ellipticities have been chosen for the calculation of the extended gas response. The results obtained for different widths and lengths (up to 20 cm) of the gas demonstrate the cone structure of the generated radiation together with a non-monotonical distribution of the ellipticity. Methods of control of the value of the ellipticity are presented and discussed. The single atom investigations have been carried out with the help of the non-perturbative theory for the ionization-free regime of interaction
Guidelines for designing 2D and 3D plasmonic stub resonators
Solmaz Naghizadeh and Sukru Ekin Kocabas
Doc ID: 278584 Received 13 Oct 2016; Accepted 28 Nov 2016; Posted 28 Nov 2016 View: PDF
Abstract: In this work we compare the performance of plasmonic waveguide integrated stub resonators based on 2D metal-dielectric-metal (MDM) and 3D slot-waveguide (SWG) geometries. We show that scattering matrix theory can be extended to 3D devices, and by employing scattering matrix theory we provide the guidelines for designing plasmonic 2D and 3D single-stub and double-stub resonators with a desired spectral response at the design wavelength. We provide transmission maps of 2D and 3D double-stub resonators versus stub lengths, and we specify the different regions on these maps that result in a minimum, a maximum or a plasmonically induced transparency (PIT) shape in the transmission spectrum. Radiation loss from waveguide terminations leads to a degradation of the 3D slot-waveguide based resonators. We illustrate improved waveguide terminations that boost resonator properties. We verify our results with 3D FDTD simulations.
Generalized projection retrieval of dispersion scans for ultrashort pulse characterization
Miguel Miranda, João Penedones, Chen Guo, Anne Harth, Maité Louisy, Anne L'Huillier, Cord Arnold, and Lana Neoričić
Doc ID: 276359 Received 14 Oct 2016; Accepted 26 Nov 2016; Posted 28 Nov 2016 View: PDF
Abstract: We present a retrieval algorithm based on generalized projections for ultrashort pulse characterization using dispersion scan (d-scan). The new algorithm is tested on several simulated cases and in two different experimental cases in the few-cycle regime. The proposed algorithm is much faster and leads to a drastic reduction of retrieval times, but performs less robust in the retrieval of noisy d-scan traces compared to the standard algorithm.
Spatial Modulation Instability of Coupled Surface Plasmon Polaritons in a Dielectric-Metal-Dielectric Structure
Kuppusamy Porsezian, monisha kumar, Patrice Dinda, Philippe Grelu, t mithun, and Uthayakumar Thangaraj
Doc ID: 275106 Received 01 Sep 2016; Accepted 25 Nov 2016; Posted 28 Nov 2016 View: PDF
Abstract: We study the spatial modulation instability (MI) in a system of coupled surface plasmon polaritons propagating at a dielectric-metal-dielectric interface . One of the dielectric medium considered is nonlinear and active, which provides enough gain to compensate for the losses in the metal. It is found that the system is unstable for both focusing or defocusing nonlinearity, with more instability in the focusing case. It is noted that nonlinearity is one of the key parameters for instability with the real part controlling the maximum MI gain and the imaginary part controlling the MI gain saturation. Gain provided by the active medium is also an important parameter for the development of MI in the system. The generated sidebands are amplified as they propagates along the interfaces. We have noted that the defocusing case requires a large gain threshold to exhibit modulation instability for a symmetric solution.
High average power, 10 GHz pulses from a very-large-mode area Er-doped fiber amplifier
Jeffrey Nicholson, Raja Ahmad, Anthony Desantolo, and Zoltan Varallyay
Doc ID: 277889 Received 30 Sep 2016; Accepted 25 Nov 2016; Posted 28 Nov 2016 View: PDF
Abstract: We demonstrate high average power, high peak power amplification of 10 GHz, picosecond and femtosecond pulses in a very-large-mode area (VLMA), Er-doped fiber with an effective area of ~1100 μm2. A high power, single-mode Raman fiber laser with up to 183 W of power at 1480 nm served as a pump source. When amplifying 3 picosecond pulses at 1560 nm, a maximum average power of 120 W was demonstrated. Using an additional highly nonlinear fiber for pulse compression before the VLMA amplifier, 130 femtosecond pulses with an average power of 115 W, peak power of 88 kW, and M2 of 1.18 were achieved. To the best of our knowledge, this is the first time ultrashort pulses in the 1550 nm wavelength region have been amplified to average powers in excess of 100 W in an Er-fiber amplifier.
Modified method for computing the optical force of the plasmonics nanoparticle from the Maxwell stress tensor
Dong Wang, Jun Song, Maozhen Xiong, Guangsheng Wang, xiao peng, and Junle Qu
Doc ID: 279950 Received 01 Nov 2016; Accepted 23 Nov 2016; Posted 28 Nov 2016 View: PDF
Abstract: By controlling the optical force, optical tweezers can manipulate many kinds of small particles without mechanical contact. In the theoretical analysis of the optical force, conventional methods are based on the integration of the Maxwell stress tensor over the outer surface of the particle, while the Maxwell stress tensor is determined by the electromagnetic field distribution around the particle itself. However, we find that this conventional method may not be appropriate in most situations, as two main issues arise, especially for plasmonics nanoparticle because of the metal involved. The first is the selection of the relative permittivity on the interface between the particle and the background medium, while the second is the use of the divergence theorem. Here, we present an improved and more correct technique to compute the optical force of optical tweezers on the plasmonics nanoparticle. The analysis of an Au-Ag core-shell nanostructure, conducted by adopting this revised method, shows that the negative force is located not only at the Fano resonance, but also at longer wavelengths.
Goos-Hänchen Shift of partially coherent light fields in Double Quantum Dot
Sajid Qamar, zia uddin, and Muqaddar Abbas
Doc ID: 276376 Received 22 Sep 2016; Accepted 23 Nov 2016; Posted 28 Nov 2016 View: PDF
Abstract: The Goos-Hänchen (GH) shifts in the reflected and the transmitted light are investigated for $p$-polarized partial coherent light beams incident on a cavity having quantum dot (QD) system as intra cavity medium. The coherent coupling between the two quantum dots via tunneling field leads to tunneling-induced transparency and giant Kerr non-linearity with vanishing absorption. The Kerr non-linearity of the double QD system thus increases the amplitude of GH shifts in the reflected and the transmitted light. The influence of the spatial coherence and the beam width of the partial coherent light fields on GH shifts in the reflected and the transmitted light are also investigated and the large GH shifts are reported for the small range of the spatial coherence and the beam width of partial coherent light field.
Three-straight-line approximation for phase delay on fiber Bragg grating reflection and its application to the mode analysis of distributed Bragg reflector laser for single frequency operation
Doc ID: 277764 Received 30 Sep 2016; Accepted 22 Nov 2016; Posted 01 Dec 2016 View: PDF
Abstract: A new mathematical algorithm for representing the phase delay on uniform-FBG reflection by a three-straight-line approximation has been developed to facilitate the mathematical treatment of the FBG response. The validity of the approximation is numerically demonstrated. By means of the developed algorithm, the mode equation in DBR linear cavity has been analytically solved, to the best of author’s knowledge, and thereby the single mode operation of the cavity could be theoretically analyzed by the tractable mathematics. It is found that the mode selectivity is dependent on the ratio of cavity spacing to FBG length, rather than the spacing itself. The developed algorithm numerically revealed the mode selectivities that remained unknown in the past single frequency DBR fiber laser studies.
High power coherent beam polarization combination of fiber lasers: progress and prospect
Pu Zhou, Zejin Liu, Pengfei Ma, Rongtao Su, Yanxing Ma, Xiaolin Wang, and Rumao Tao
Doc ID: 278009 Received 03 Oct 2016; Accepted 21 Nov 2016; Posted 22 Nov 2016 View: PDF
Abstract: Coherent polarization beam combining (CPBC) of fiber lasers has the potential to scaling the output total power while simultaneously maintaining good beam quality. In this paper, we will present the very recent technical advance in single channel coherently combinable linear polarized narrow linewidth fiber amplifier and high power CPBC system. The noise property of a recently developed near 2-kW fiber amplifier and its feasibility in CPBC system, CPBC of four 500-watt level fiber amplifiers and two kilo-watt fiber amplifiers are demonstrated for the first time, which is also the first result for 2 kilowatt CPBC system. We have also performed numerical analysis on the performance scaling of CPBC, and deduced handy design guidelines for CPBC of a 64-element high power system.
Effect of partial coherence on diffraction intensity of a Gaussian Schell-Model beam using two-level atomic grating
Sajid Qamar, Zia uddin, Sobia Asghar, and Shahid Qamar
Doc ID: 277564 Received 26 Sep 2016; Accepted 19 Nov 2016; Posted 22 Nov 2016 View: PDF
Abstract: The role of coherence on diffraction intensity is investigated for a partially coherent incident Gaussian Schell-model (GSM) beam which is diffracted from a two-level atomic grating. It is shown that the performance of the atomic grating is greatly influenced by the spectral coherence width of the partially coherence fields (PCFs). It is observed that the diffraction intensity decreases as beam-width and spatial coherence increase, however, it increases with interaction length. It is also shown that the diffraction intensity also depends on the mode index of the partially coherent incident light field and a relatively large diffraction intensity can be obtained for a certain mode-index. The scheme provides possibilities for the potential applications of atomic grating in lensless imaging using partially coherent light field.
Quasi-phase-matched high harmonic generation in corrugated micrometer-scale waveguides
Doc ID: 273465 Received 09 Aug 2016; Accepted 19 Nov 2016; Posted 22 Nov 2016 View: PDF
Abstract: The high harmonic generation in periodically corrugated submicrometer waveguides is studied numerically. Plasmonic field enhancement in the vicinity of the corrugations allows to use low pump intensities. Simultaneously, periodic placement of the corrugations leads to quasi-phase-matching and corresponding increase of the high harmonic efficiency. The optimization of waveguide geometry is performed, and the resulting spectra are analyzed by the means of (1+1)D numerical model.
Modifications in lithium niobium silicate glass by femtosecond laser direct writing: morphology, crystallization, and nanostructure
Bertrand Poumellec, Jing CAO, LEO MAZEROLLES, Matthieu Lancry, and Francois Brisset
Doc ID: 275923 Received 14 Sep 2016; Accepted 18 Nov 2016; Posted 22 Nov 2016 View: PDF
Abstract: We explore the femtosecond laser-induced modifications (i.e., morphology, crystallization, and nanostructure) in lithium niobium silicate glass at high-repetition-rate (1030nm, 300fs, 300 kHz) to get insight on the ultrafast laser-matter interaction according to pulse energy and writing configuration (laser polarization direction versus scanning one). The modifications can be classified into three regimes according to pulse energy: 1) at 0.3-0.4 µJ/pulse, one amorphous zone with a larger sensitivity to the chemical etching; 2) at 0.5-0.9 µJ/pulse, textured nanocrystals embedded in self-organized nanostructures whatever the laser polarization or scanning direction is; 3) at 1.0-2.2 µJ/pulse, crystallization dependent on the writing configuration. This finding may guide users to the optimal parameters for the applications in optics.
Comparative study of multioctave supercontinuum generation in fused silica, YAG and LiF in the range of anomalous group velocity dispersion
Audrius Dubietis, Nail Garejev, and Gintaras Tamosauskas
Doc ID: 276449 Received 22 Sep 2016; Accepted 18 Nov 2016; Posted 18 Nov 2016 View: PDF
Abstract: We present spectral measurements that uncover the detailed dynamics of the supercontinuum generation in fused silica, YAG and LiF crystals when pumped with 100 fs pulses with a central wavelength of 2.3 μm, which falls into the range of anomalous group velocity dispersion of the media. The multi-octave supercontinuum spectra, which span from the ultraviolet to the mid-infrared, are recorded by means of high-dynamic range measurements over the entire wavelength range covered by the supercontinuum radiation. The spectral dynamics versus the input pulse energy uncovers different mechanisms of spectral broadening, which are characterized by the occurrence of specific, but well-distinguished spectral signatures and which are interpreted in terms of plasma-induced and anomalous group velocity dispersion-induced compression of the driving pulse.
Controllable single-photon transport in one-dimensional coupled-resonator waveguide coupled to two nanocavities interacting with atoms
Wen-An Li, Xiao-Shi Li, Jin-Jiang Huang, Cai-Mei Pan, Zhi-Feng Chen, and Yuan Chen
Doc ID: 275228 Received 02 Sep 2016; Accepted 17 Nov 2016; Posted 18 Nov 2016 View: PDF
Abstract: We investigate controllable single-photon transport in one-dimensional coupled-resonator waveguide (CRW) with a nonlinear dispersion relation coupled to two nanocavities interacting with atoms. The reflection and transmission coefficients for a single photon propagating in such system are deduced by using the discrete coordinates approach. The resonator-nanocavity coupling strength, atom-nanocavity coupling coefficient, and the detuning between the incident photon and the atom, respectively, which affect the transport properties of the single photon, are analyzed. It is found that some useful informa- tion such as atom-nanocavity coupling strength can be extracted from the single-photon transmission spectrum under proper parameters settings. We also study how the coupling between two nanocavities affects the single-photon transmission property.
Dispersion analysis in micron resolution spectral domain optical coherence tomography
Xiupin Wu and Wanrong Gao
Doc ID: 273202 Received 04 Aug 2016; Accepted 17 Nov 2016; Posted 22 Nov 2016 View: PDF
Abstract: One of the main factors that limit the effective axial resolution of spectral domain optical coherence tomography in live tissue imaging is the tissue induced dispersion. In this work, first the methods are reviewed that have been proposed to compensate the dispersion effects in various applications. Simple formulas are then derived that can be used to estimate the orders of the dispersion that may have significant influences. The formulas are then used to calculate relative contributions of various dispersion orders to the decrease of the axial resolution, in which the dispersion properties of water was employed as a first approximation to tissue. It is found that up to forth order dispersion should be compensated when the theoretical resolution approaches to 1 µm. The Wigner distributions of the interference spectral signals for an interface beneath a surface are presented, where the dispersion order contained in the interference signal can be discerned intuitively. The results are helpful for choosing the appropriate methods for dispersion compensation.
Teleportation of Entanglement Using a Three-Particle Entangled W State
zaichen zhang, Xiaoqin Gao, Yanxiao Gong, Bin Sheng, and Xutao Yu
Doc ID: 276269 Received 20 Sep 2016; Accepted 16 Nov 2016; Posted 16 Nov 2016 View: PDF
Abstract: We present a scheme for teleporting an unknown three-particle entangled W state from a sender to either of two receivers. Two partial three-particle entangled W states are used as the quantum channel. The success probability of teleportation depends on the entanglement degree of shared W states, which equals 4/9 for a quantum channel composed of two maximally-entangled three-particle W states. The proposed scheme can be generalized to transmit an unknown m-particle entangled W state to any of m-1 receivers and will be applied to long-distance transmission as well.
Higher-order squeezing and entanglement of harmonic oscillators in superconducting circuits
FEI WANG, Wei Nie, and Choo Oh
Doc ID: 278254 Received 07 Oct 2016; Accepted 16 Nov 2016; Posted 16 Nov 2016 View: PDF
Abstract: We show that it is possible to obtain higher-order squeezing and entanglement between a pair of harmonic oscillators coupled to a single $\Delta$-type artificial atom, which is realized because of the broken mirror symmetry of the effective potential in the superconducting circuits. Under the three-photon resonance and adiabatic conditions, the system can act as a coherence-controlled atomic reservoir, resulting in the generation of higher-order nonclassicality at steady state. The stable higher-order nonclassical correlations of the two harmonic oscillators in this solid-state device may find potential applications in gravitational wave detection and quantum communications.
Advances in active broadband spectroscopy for health and environmental applications
Kevin Cossel, Eleanor Waxman, Geoffrey Blake, Ian Finneran, Jun Ye, and Nathan Newbury
Doc ID: 275946 Received 19 Sep 2016; Accepted 15 Nov 2016; Posted 15 Nov 2016 View: PDF
Abstract: Broadband spectroscopy is an invaluable tool for measuring multiple gas-phase species simultaneously. In this work we review current applications for broad-band spectroscopy. We discuss components of broad-band spectroscopy including light sources, absorption cells, and detection methods and then discuss specific combinations of these components in commonly-used techniques. We finish this review by discussing potential future advances in techniques and applications of broad-band spectroscopy.
High efficiency phase flattening based Laguerre-Gauss (LG) spectrometer using variable focus lenses
Mumtaz Sheikh, Haad Rathore, and Sohaib Rehman
Doc ID: 270302 Received 12 Jul 2016; Accepted 15 Nov 2016; Posted 16 Nov 2016 View: PDF
Abstract: We propose a novel high-efficiency no-moving-parts Laguerre-Gauss (LG) spectrometer using two variable focus lenses and a variable sized pinhole that overcomes the limitations of the classical, projective, phase flattening technique for measuring the Laguerre-Gauss (LG) spectrum of light beams. Simulation results show that the coupling losses are virtually zero and the only losses are ring losses which are mode-dependent but beam waist-independent. Hence, the detection efficiency for all modes is simultaneously the maximum possible irrespective of the beam waist of the LG modes chosen for the decomposition. The losses can also be easily pre-calibrated to remove the efficiency bias amongst different modes.
Polarization-sensitive dual-comb spectroscopy
Shinichi Watanabe, Kana Sumihara, Sho Okubo, Makoto Okano, and Hajime Inaba
Doc ID: 275043 Received 31 Aug 2016; Accepted 15 Nov 2016; Posted 16 Nov 2016 View: PDF
Abstract: We introduce a method of polarization-sensitive dual-comb spectroscopy. This technique is a combination of dual-comb spectroscopy and rotating compensator polarimetry, in which the rotation frequency of the compensator is optimized in order to establish the frequency sidebands of each comb tooth. Thus, we can determine the polarization state of each comb tooth by analyzing the amplitudes and phases of the sidebands. For a frequency resolution of 48 MHz and a measurement time of 726.5 s, the precisions of the orientation and the ellipticity angles of the individual comb teeth are approximately 0.01 rad.
Marcello Ferrera, Nathaniel Kinsey, Amr Shaltout, Clayton DeVault, Vladimir Shalaev, and Alexandra Boltasseva
Doc ID: 264373 Received 06 May 2016; Accepted 11 Nov 2016; Posted 21 Nov 2016 View: PDF
Abstract: The field of integrated plasmonics is as multifaceted as few other disciplines in applied science, mainly due to its intrinsic “hybrid” nature of combining materials and strategies borrowed from both electronics and photonics. Because of the multitude of angles under which the plasmonic world could be analyzed, and also because of the intrinsic interest behind this branch of physics, numerous review papers have been recently published with the attempt to exhaustively describe this subject and its possible future developments. However, despite the considerable literature already available, few important aspects deserve a deeper investigation. Among these dark spots we find the lack of a general overview of active plasmonics, specifically focused on the possibility to dynamically alter the optical properties of the constituent plasmonic materials in order to gain full active control over the overall desired functionality. The present review focuses its attention on the possibility to tune the optical properties of said components, deliberately neglecting those strategies relying on the dynamic properties of the dielectric component. The present work will also attempt to outline experimental and multidisciplinary aspects of tunable plasmonic devices giving only a marginal overview of telecom applications for which a considerable literature is already available.
Analytical solutions to the finite-pulse Bloch model for multidimensional coherent spectroscopy
Christopher Smallwood, Travis Autry, and Steven Cundiff
Doc ID: 273905 Received 18 Aug 2016; Accepted 08 Nov 2016; Posted 09 Nov 2016 View: PDF
Abstract: We present perturbative analytical solutions to the optical Bloch equations at third-order, with finite duration Gaussian pulse envelopes. We find that a given double-sided Feynman diagram in this approximation can be conveniently described in the frequency domain as a product of the expression in the impulsive limit and a finite-pulse factor. Finite-pulse effects are Feynman-diagram-dependent, however, and include nontrivial phase corrections that can occur even in the case of transform-limited pulses. The results constitute a practical framework for modeling phenomena in multidimensional coherent spectroscopy that cannot easily be captured in the impulsive limit, including the roles of bandwidth, resonance, and pulse chirp.
On the broadband continuous polarization-independent excitation of surface-plasmon-polariton waves: energy harvesting applications
Mahmoud Atalla and M. Attia
Doc ID: 273620 Received 10 Aug 2016; Accepted 23 Oct 2016; Posted 02 Dec 2016 View: PDF
Abstract: In a dye-sensitized solar cell (DSC), the broadband continuous excitation of surface-plasmon-polariton (SPP) waves for both TM- and TE-polarization states was studied theoretically. It was found that a TM-polarized broadband continuous excitation in a DSC can be achieved over 300 nm wavelength range provided that light is incident through accordingly varying refractive index material atop the DSC while a back-contact metallic grating is incorporated. By neighboring the DSC by another absorber material, the plasmonic dissipation due to the guiding metal can be significantly reduced while maintaining overall high EQE. Moreover, It is shown that if the metallic back-contact possesses real part of relative permittivity Re(epsilon) that broadband increases, there may exist a TM-polarized SPP wave branch with the real part of its relative wavenumber broadband increases. If multiple layers in the DSC have broadband increasing Re(epsilon), multiple broadband increasing TM- and TE-polarized SPP waves could be guided by the back-contact. It is shown that in such configurations the broadband continuous excitation of TM- and TE-polarized SPP waves is possible, and ways to make it polarization-independent are pointed out. The broadband continuous excitation of SPP waves would be useful for energy harvesting, communications and bio-sensing applications.
Modulation instability induced by higher-order nonlinear dispersions in nonlinear positive-negative index couplers with exponential saturable nonlinearity
Mohamadou Alidou, Aboukar NO LAST NAME GIVEN, and Alim Dia
Doc ID: 264583 Received 04 May 2016; Accepted 04 Oct 2016; Posted 04 Oct 2016 View: PDF
Abstract: We study the modulational instability (MI) in positive-negative couplers with higher-order effects and exponential saturable nonlinearity. Special attention is paid tothe influence of self-steepening (SS); intrapulse Raman scattering and second-order nonlinear dispersion (SOND) on the MI gain. The results show that saturable nonlinearity can be used to control the generation of sidebands through the coupler. We show that in normal dispersion regime, the instability gain exists even if theperturbation frequency ($\Omega$) is zero. The instability gain at $\Omega=0$ is nil, when the dispersion is anomalous. We find that the magnitude and sign of SOND exert strong influences on MI sideband. Moreover, by adjusting the various parameters such as SS, intrapulse Raman scattering, and SOND we obtain new instability regions.These results can be helpful to understand the generation of soliton-like exitaction in nonlinear oppositely coupler and can be potentially useful for future experiments.