Early Posting

Accepted papers to appear in an upcoming issue

Optica Publishing Group posts prepublication articles as soon as they are accepted and cleared for production. See the FAQ for additional information.

High Sensitive concentration detection of Trace Doxycycline in Solution by molecular imprinting based on Surface Plasmon Resonance Technology

Zhitao Yang, Shijie Wang, Sijia Han, and Lingzui Wei

DOI: 10.1364/JOSAB.508037 Received 12 Oct 2023; Accepted 26 Mar 2024; Posted 26 Mar 2024  View: PDF

Abstract: The abuse of Doxycycline (DC) will lead to its residues in animals and water environment, posing a threat to human health and the environment. So it is of great significance to detect the micro-content of DC in solution. In this paper, based on surface plasmon resonance (SPR) technology, we develop a detection method for trace DC in solution by modifying SPR sensor chip with molecular imprinting technique. The results show that the SPR sensor could specifically recognize DC in solution, and the detection limit of this method reaches 10-6 μg/mL which is 100 times lower than that of ELISA method. The detection signal is linear in the concentration range of 10-6 ~ 10 μg/ mL. This method has the characteristics of low detection limit, large linear range and high specificity for DC.

Noise-like pulses: stabilization, production and application

Sergey Kobtsev and Andrey Komarov

DOI: 10.1364/JOSAB.517753 Received 03 Jan 2024; Accepted 21 Mar 2024; Posted 26 Mar 2024  View: PDF

Abstract: Various aspects are analysed, which are related to generation of unusual laser pulses with stochastic internal structure known as noise-like pulses. A new mechanism of their formation is proposed on the basis of an analogy between a noise-like pulse and a drop of soliton liquid. The properties of noise-like pulses are considered. It is further noted that these pulses are more and more used in a number of applications (supercontinuum generation, industrial processing, medical treatment, etc.). The causes of low coherence of noise-like pulses are identified. A method of coherence degree measurement relying on autocorrelation function of these pulses is discussed. The most promising configurations for generation of noise-like pulses are provided.

Tunable O-band high-tolerance silicon mode multiplexer based on phase-mismatched asymmetric directional couplers

Kodai Nakamura, Takeshi Fujisawa, Takanori Sato, and Kunimasa Saitoh

DOI: 10.1364/JOSAB.515894 Received 12 Dec 2023; Accepted 18 Mar 2024; Posted 18 Mar 2024  View: PDF

Abstract: Small silicon-on-insulator (SOI)-based tunable O-band TE0-TE1 and TE0-TE2 mode multiplexers (MUXs) based on phase-mismatched asymmetric directional couplers (ADCs) and phase-adjustment region are theoretically and experimentally demonstrated. We designed ADCs with an intentionally phase-mismatched coupling region to suppress wavelength dependence and improve fabrication error tolerance. Even at worst, the fabricated O-band TE0-TE2 mode MUX has −0.71 dB transmission. Moreover, to improve performance, we proposed and designed three-section tapered ADCs (3STADCs) divided into three regions. We theoretically show that the TE0-TE1 and TE0-TE2 mode MUXs based on the 3STADC have more than −0.28 dB and −0.36 dB transmission, respectively.

High efficiency independent modulation at dual-wavelength based on Pancharatnam-Berry and propagation phases

Minglei He, Jiepeng Wu, Haohan Chen, Hao Wang, Xinen Wu, Qianbin Feng, Qiwen Wu, Xiaosong Wu, Haiying Liu, Qiang Li, and Lijun Wu

DOI: 10.1364/JOSAB.516201 Received 21 Dec 2023; Accepted 18 Mar 2024; Posted 18 Mar 2024  View: PDF

Abstract: Metasurfaces capable of controlling multiple wavelengths independently have attracted broad interests these years due to their significance in multi-channel information processing applications. Previous solving strategies include spatial multiplexing or extensive searching for appropriate structures, both of which have their own disadvantageous, such as low efficiency, large computer resource requirement or time-consuming. In this paper, by combining the Pancharatnam-Berry (PB) phase and propagation phase, we propose a strategy to simplify the design complexity in a dual-wavelength metasurface system, in which two simplest rectangular-shaped dielectric pillars (T₁ and T₂) with different aspect ratios are chosen as basic structures and crossed at the geometric center to achieve manipulation. The larger pillar T₂ controls the longer wavelength through the PB phase while the smaller T₁ acts a perturbation to T₂. The crossed T₁&T₂ is studied as a whole to tune the short wavelength. The investigations by the multipole expansion method reveals that the polarization conversion ratio of the meta-atoms is dependent on the interference of the formed multipoles. To validate the proposed strategy, a dual-wavelength achromatic metalens and a wavelength-multiplexed holographic metasurface operating at the infrared thermal imaging band are designed. Our design strategy can find widespread applications in metasurfaces where multiple objectives are required to realize.

Low-kappa DBR grating filters on an InP Generic Photonic Integration Foundry Platform

Rakesh Ranjan Kumar, Andreas Hänsel, Pau Castera, Nicolas Volet, and Martijn Heck

DOI: 10.1364/JOSAB.518800 Received 16 Jan 2024; Accepted 18 Mar 2024; Posted 18 Mar 2024  View: PDF

Abstract: We demonstrate narrow-bandwidth, low-kappa, DBR grating filters on an Indium phosphide generic foundry platform. With the varying corrugation widths of the DBR grating, we achieve flexibility in the design of the coupling coefficients from 10 to 50 cm-1, which correspond to grating bandwidths of 0.67 nm to 1.28 nm, respectively. These values are experimentally observed and agree well with the theoretical analysis. The DBR grating is based on periodic rectangular grooves in quaternary material that is placed between the waveguide core and cladding region. Such configurations of DBR grating provide a low propagation loss of ~2 dB/cm near the telecom band around 1550 nm.

Super-resolution spectroscopy via spectrum slicing with a Fabry-Pérot cavity

Lin Chen, peng yang, Boya Xie, and Sheng Feng

DOI: 10.1364/JOSAB.516769 Received 21 Dec 2023; Accepted 15 Mar 2024; Posted 15 Mar 2024  View: PDF

Abstract: Spectroscopy is one of the most powerful technical tools that are widely used in the study of natural sciences and the development of high technologies. To improve the performance of a traditional dispersive spectrometer, there is a competition between its spectral resolution and the geometric volume; a higher resolution is usually accompanied by a higher cost as well. However, a growning body of evidence suggests an urgent demand for miniaturized spectrometers with high spectral resolution and low costs. In this paper, we propose and study super-resolution spectroscopy via spectrum slicing by use of a Fabry–Perot (FP) cavity combined with a traditional spectrometer. The cavity functions as a spectral filter to slice into discrete pieces the continuous spectrum of the input light. For each given cavity length, the cavity outputs a set of sliced spectral pieces that are then analyzed and recorded by the subsequent spectrometer. By scanning the cavity length, one will have multiple sets of sliced spectral pieces that are then finally fused to recover a resolution-enhanced copy of the input spectrum. A theoretical analysis for the super-resolution spectroscopy is provided to prove the feasibility of the proposal, as further confirmed by Matlab numerical simulation. The studied spectral analysis technique will benefit the research fields in need of high resolution spectrometers with moderate device volumes and low costs.

Laser-pump-resistive-probe technique to study nanosecond-scale relaxation processes

Mark Blumenau and Alexander Kuntsevich

DOI: 10.1364/JOSAB.517905 Received 08 Jan 2024; Accepted 14 Mar 2024; Posted 15 Mar 2024  View: PDF

Abstract: Standard optical pump-probe methods analyze a system's temporal response to a laser pulse within sub-femtoseconds to several nanoseconds, constrained by the optical delay line's length. While resistance is a sensitive detector in various fields, its measurements are typically slow (>microseconds) due to stabilization requirements. We suggest here atime-resolved pump-probe technique which combines an optical "Pump" pulse and a rectangular electrical "Probe" pulse through the sample, measuring transmission in a 50 Ohm matched circuit with a digital oscilloscope. This allows electrically-driven delays from nanoseconds to seconds. Demonstrations include studying heat-induced changes in a thin amorphous VO$_x$ film and carrier relaxation in a CdS photoresistor, showcasing potential applications in heat transfer, biochemical reactions, and gradual electronic transformations.

Tunable Non-Specular Effects on Hyperbolic Crystal Coated with Single Layer of Graphene

Waleed waseer, QAisar Naqvi, and Maria Iqbal

DOI: 10.1364/JOSAB.516149 Received 27 Dec 2023; Accepted 13 Mar 2024; Posted 14 Mar 2024  View: PDF

Abstract: In this work, we have theoretically investigated the tunable non-specular effects, specifically Imbert-Fedorov andGoos-H¨anchen shifts on a graphene-based uniaxial hyperbolic crystal geometry. The hyperbolic crystal is made ofhexagonal boron nitride and the source of excitation is a circularly polarized light beam. The influence of chemicalpotential and absolute temperature of the graphene on these effects is examined. Notably, the research reveals that, theshifts exhibit complex and significantly varying behavior within and outside the infrared reststrahlen frequency-bandsof hyperbolic crystal.

Fano resonance and enhanced sensing in the excitation of surface phonon polariton

Qiwen Zhao, Chenyi Yao, Ying He, yanfang yang, and Hui-Fang Zhang

DOI: 10.1364/JOSAB.518702 Received 16 Jan 2024; Accepted 13 Mar 2024; Posted 14 Mar 2024  View: PDF

Abstract: The surface phonon polariton is a collective oscillation mode of phonons and incident electromagnetic waves in polar dielectric materials. Compared with surface plasmon polaritons, it has low loss and can be applied to the mid-infrared band. A Surface phonon resonance sensor based on waveguide-coupling is proposed. The sensor structure is a typical Kretschmann configuration consisting of a germanium (Ge) prism, a silicon carbide (SiC) layer, diindium triselenide (In2Se3) , Titanium Dioxide (TiO2), and the surrounding dielectrics. The reflectivity possesses significant asymmetric Fano-resonance dips. The sensitivity and Q-factor of the proposed sensor can be enhanced by and . Our investigation provides an alternative method for refractive index sensing, thus opening up opportunities for the design of various phonon devices based on Fano-resonance.

In-situ holograms and two-wave mixing amplification of conical diffraction vector waves

Muhammad Waqar Iqbal, Yuliia Shiposh, Anton Kohutych, Nicolas Marsal, Alexander Grabar, and Germano Montemezzani

DOI: 10.1364/JOSAB.517056 Received 27 Dec 2023; Accepted 12 Mar 2024; Posted 13 Mar 2024  View: PDF

Abstract: Holographic recording and selective reconstruction and amplification of conical diffraction vector waves is demonstrated using a nonlinear photorefractive Sn₂P₂S₆ crystal acting simultaneously as medium producing the conical diffraction effect and as holographic storage material. It is shown that upon propagation of the object wave along one of the optical axes of the biaxial crystal, the azimuthal spreading of the local linear polarizations across the conical diffraction ring allows its holographic recording with any combinations of the object and reference wave's input polarizations, including mutually orthogonal ones. We discuss the dependence of the recording and read-out polarizations on the recovered and amplified patterns and provide a simplified model qualitatively accounting for all the main observed features. The approach permits a tailoring of the reconstructed or amplified vector waves in terms of intensity and polarization distributions and opens interesting perspectives for their static or dynamic manipulation.

Berry phase and the Mandel parameter of the non-degenerate parametric amplifier

Juan Vega, Enrique Choreño, Didier Ojeda-Guillén, and Roberto Mota

DOI: 10.1364/JOSAB.517533 Received 03 Jan 2024; Accepted 10 Mar 2024; Posted 15 Mar 2024  View: PDF

Abstract: We study the non-degenerate parametric amplifier problem from an algebraic approach of the $SU(1,1)$ group. We write the Hamiltonian of this problem in terms of the boson generators of the $SU(1,1)$ group and the difference operator. We apply the tilting transformation to our results to exactly solve this Hamiltonian and obtain its energy spectrum and eigenfunctions. Then, by assuming that our Hamiltonian is an explicit function of time we calculate its Berry phase. Finally we obtain the Mandel $Q-$parameter of the photon numbers $n_a$ and $n_b$.