Contents
2024
Volume: 12 Issue 11
32 Article(s)
Export citation format
ADVANCING INTEGRATED PHOTONICS: FROM DEVICE INNOVATION TO SYSTEM INTEGRATION
Advancing Integrated Photonics feature issue introduction
Liang Feng, Junqiu Liu, and Cheng Wang
We give an introduction to the feature issue composed of eight articles on Advancing Integrated Photonics.We give an introduction to the feature issue composed of eight articles on Advancing Integrated Photonics..
Photonics Research
- Publication Date: Oct. 28, 2024
- Vol. 12, Issue 11, AIP1 (2024)
High capacity, low power, short reach integrated silicon photonic interconnects
Andrew Netherton, Mario Dumont, Zachary Nelson, Jahyun Koo... and John E. Bowers|Show fewer author(s)
The architecture and component technology of a low power, high capacity, short reach optical interconnect are detailed. Measurements...show moreThe architecture and component technology of a low power, high capacity, short reach optical interconnect are detailed. Measurements from high-performance 300 mm silicon photonics components that comprise the system are shown, along with a quantum-dot mode-locked laser 20-channel comb source with free space wall plug efficiencies up to 17%, advanced packaging techniques for 3D silicon photonic-electronic integration, and schematics for integrated electronics that control the photonic integrated circuits. Techniques for operating such a system in the presence of changing ambient temperature are addressed. Experiments on a 1 Tbps design are conducted with an optical link experiment indicating sub-picojoule/bit energy consumption at scale..
Photonics Research
- Publication Date: Oct. 28, 2024
- Vol. 12, Issue 11, A69 (2024)
Reviews
Nonlinear Optics
Multimode solitons in optical fibers: a review | Editors' Pick
Yifan Sun, Pedro Parra-Rivas, Govind P. Agrawal, Tobias Hansson... and Stefan Wabnitz|Show fewer author(s)
This review describes recent theoretical and experimental advances in the area of multimode solitons, focusing primarily on multimode...show moreThis review describes recent theoretical and experimental advances in the area of multimode solitons, focusing primarily on multimode fibers. We begin by introducing the basic concepts such as the spatial modes supported by a multimode fiber and the coupled mode equations for describing the different group delays and nonlinear properties of these modes. We review several analytic approaches used to understand the formation of multimode solitons, including those based on the 3D+1 spatiotemporal nonlinear Schrödinger equation (NLSE) and its approximate 1D+1 representation that has been found to be highly efficient for studying the self-imaging phenomena in graded-index multimode fibers. An innovative Gaussian quadrature approach is used for faster numerical simulations of the 3D+1 NLSE. The impact of linear mode coupling is discussed in a separate section using a generalized Jones formalism because of its relevance to space-division multiplexed optical communication systems. The last section is devoted to the relevant experimental studies involving multimode solitons..
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2581 (2024)
Research Articles
Editorial
Celebrating leadership and innovation—introducing a new interview series with pioneering women in optics and photonics
Lan Yang
Photonics Research Editor-in-Chief Lan Yang introduces the new interview article series.Photonics Research Editor-in-Chief Lan Yang introduces the new interview article series..
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, ED1 (2024)
Fiber Optics and Optical Communications
Two-photon 3D printed fiber-optic Fabry–Perot probe for triaxial contact force detection of guidewire tips
Ruixue Yin, Yuhang Yang, Linsong Hou, Heming Wei... and Wenjun Zhang|Show fewer author(s)
The demand for real-time feedback and miniaturization of sensing elements is a crucial issue in the treating vascular diseases with minimally...show moreThe demand for real-time feedback and miniaturization of sensing elements is a crucial issue in the treating vascular diseases with minimally invasive interventions. Here, Fabry–Perot microcavities fabricated via direct laser writing using a two-photon polymerization technique on fiber tips are proposed, designed, simulated, and experimentally demonstrated as a miniature triaxial force sensor for monitoring real-time interactions between the tip of a guidewire and human blood vessels and tissues during minimally invasive surgeries. The sensor contains four fiber tip-based Fabry–Perot cavities, which can be seamlessly integrated into medical guidewires and achieves three-axis force decoupling through symmetrically arranged flexible structures. The results showed that the proposed sensor achieved a cross-sectional diameter of 890 μm and a high sensitivity of about 85.16 nm/N within a range of 0 to 0.5 N with a resolution of hundreds of micro-Newtons. The proposed triaxial force sensor exhibits high resolution, good biocompatibility, and electromagnetic compatibility, which can be utilized as an efficient monitoring tool integrated into minimally invasive surgical intervention devices for biomedical applications..
Photonics Research
- Publication Date: Oct. 29, 2024
- Vol. 12, Issue 11, 2474 (2024)
Superfine multiresonant fiber grating sensors assisted with silica capillaries
Kaiwei Li, Yongguang Xiao, Fu Liu, Zhiyong Yang... and Jacques Albert|Show fewer author(s)
We propose and demonstrate a superfine multiresonant fiber grating sensor characterized by superior spectral resolution and enhanced...show moreWe propose and demonstrate a superfine multiresonant fiber grating sensor characterized by superior spectral resolution and enhanced sensing capabilities. This sensor can be easily constructed by inserting a tilted fiber Bragg grating (TFBG) probe into a silica capillary filled with a refractive index (RI) matching oil. As the fiber cladding, the RI-matching oil, and the capillary all have the same RI, the cladding modes excited by the TFBG can extend into the RI-matching oil and capillary, facilitating surface sensing outside the capillary. Our study shows that the number of cladding modes increases, and the resonance spectrum becomes denser as the outer diameter of the capillary gets larger. As a result, the detection accuracy of RI based on mode cutoff wavelength identification can be improved. Particularly, with a capillary diameter of 1 mm, the heightened spectral density enhances refractometric accuracy by nearly an order of magnitude compared to the intrinsic TFBG. The superfine multiresonant fiber grating sensor proposed here is flexible in configuration and easy to fabricate, providing a new strategy for developing new fiber sensing devices..
Photonics Research
- Publication Date: Oct. 29, 2024
- Vol. 12, Issue 11, 2488 (2024)
Maximizing transmission capacity in optical communication systems utilizing a microresonator comb laser source with adaptive modulation and bandwidth allocation strategies | Editors' Pick
Jun Hu, Wei Wang, Zhenyu Xie, Chengnian Liu... and Daquan Yang|Show fewer author(s)
Traditional optical communication systems employ bulky laser arrays that lack coherence and are prone to severe frequency drift....show moreTraditional optical communication systems employ bulky laser arrays that lack coherence and are prone to severe frequency drift. Dissipative Kerr soliton microcombs offer numerous evenly spaced optical carriers with a high optical signal-to-noise ratio (OSNR) and coherence in chip-scale packages, potentially addressing the limitations of traditional wavelength division multiplexing (WDM) sources. However, soliton microcombs exhibit inhomogeneous OSNR and linewidth distributions across the spectra, leading to variable communication performance under uniform modulation schemes. Here, we demonstrate, for the first time, to our knowledge, the application of adaptive modulation and bandwidth allocation strategies in optical frequency comb (OFC) communication systems to optimize modulation schemes based on OSNR, linewidth, and channel bandwidth, thereby maximizing capacity. Experimental verification demonstrates that the method enhances spectral efficiency from 1.6 to
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2573 (2024)
Holography, Gratings, and Diffraction
Speckle-free holography with a diffraction-aware global perceptual model
Yiran Wei, Yiyun Chen, Mi Zhou, Mu Ku Chen... and Zihan Geng|Show fewer author(s)
Computer-generated holography (CGH) based on neural networks has been actively investigated in recent years, and convolutional...show moreComputer-generated holography (CGH) based on neural networks has been actively investigated in recent years, and convolutional neural networks (CNNs) are frequently adopted. A convolutional kernel captures local dependencies between neighboring pixels. However, in CGH, each pixel on the hologram influences all the image pixels on the observation plane, thus requiring a network capable of learning long-distance dependencies. To tackle this problem, we propose a CGH model called Holomer. Its single-layer perceptual field is 43 times larger than that of a widely used
Photonics Research
- Publication Date: Oct. 10, 2024
- Vol. 12, Issue 11, 2418 (2024)
Imaging Systems, Microscopy, and Displays
Accurate 3D single-molecule localization via vectorial in situ point spread function retrieval and aberration assessment
Xinxun Yang, Hongfei Zhu, Yile Sun, Hanmeng Wu... and Xu Liu|Show fewer author(s)
Single-molecule localization microscopy (SMLM) gradually plays an important role in deep tissue imaging. However, current SMLM...show moreSingle-molecule localization microscopy (SMLM) gradually plays an important role in deep tissue imaging. However, current SMLM methods primarily rely on fiducial marks, neglecting aberrations introduced by thick samples, thereby resulting in decreased image quality in deep tissues. Here, we introduce vectorial in situ point spread function (PSF) retrieval (VISPR), a method that retrieves a precise PSF model considering both system- and sample-induced aberrations under SMLM conditions. By employing the theory of vectorial PSF model and maximum likelihood estimation (MLE) phase retrieval, VISPR is capable of reconstructing an accurate in situ 3D PSF model achieving the theoretically minimum uncertainty and accurately reflecting three-dimensional information of single molecules. This capability enables accurate 3D super-resolution reconstruction in deep regions away from the coverslips. Additionally, VISPR demonstrates applicability in low signal-to-noise ratio scenarios and compatibility with various SMLM microscope modalities. From both simulations and experiments, we verified the superiority and effectiveness of VISPR. We anticipate that VISPR will become a pivotal tool for advancing deep tissue SMLM imaging..
Photonics Research
- Publication Date: Oct. 10, 2024
- Vol. 12, Issue 11, 2447 (2024)
Predictive pixel-wise optical encoding: towards single-shot high dynamic range moving object recognition
Yutong He, Yu Liang, Honghao Huang, Chengyang Hu... and Hongwei Chen|Show fewer author(s)
Conventional low dynamic range (LDR) imaging devices fail to preserve much information for further vision tasks because of the...show moreConventional low dynamic range (LDR) imaging devices fail to preserve much information for further vision tasks because of the saturation effect. Thus, high dynamic range (HDR) imaging is an important imaging technology in extreme illuminance conditions, which enables a wide range of applications, including photography, autonomous driving, and robotics. Mainstream approaches require multi-shot methods because the conventional camera can only control the exposure globally. Although they perform well on static HDR imaging, they face a challenge with real-time HDR imaging for motional scenes because of the artifact and time latency caused by multi-shot and post-processing. To this end, we propose a framework, termed POE-VP, which achieves single-shot HDR imaging via a pixel-wise optical encoder driven by video prediction. We use highlighted motional license plate recognition as a downstream vision task to demonstrate the performance of POE-VP. From the results of simulation and real scene experiments, we validate that POE-VP outperforms conventional LDR cameras by more than 5 times in recognition accuracy and by more than 200% in information entropy. The dynamic range could reach 120 dB, and the captured data size is verified to be lower than mainstream multi-shot methods by 67%. The running time of POE-VP is also validated to satisfy the needs of high-speed HDR imaging..
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2524 (2024)
Multifunctional computational fluorescence self-interference holographic microscopy | Editors' Pick
Wenxue Zhang, Tianlong Man, Minghua Zhang, Hongqiang Zhou... and Yuhong Wan|Show fewer author(s)
Fluorescence microscopy is crucial in various fields such as biology, medicine, and life sciences. Fluorescence self-interference...show moreFluorescence microscopy is crucial in various fields such as biology, medicine, and life sciences. Fluorescence self-interference holographic microscopy has great potential in bio-imaging owing to its unique wavefront coding characteristics; thus, it can be employed as three-dimensional (3D) scanning-free super-resolution microscopy. However, the available approaches are limited to low optical efficiency, complex optical setups, and single imaging functions. The geometric phase lens can efficiently manipulate the optical field’s amplitude, phase, and polarization. Inspired by geometric phase and self-interference holography, a self-interference fluorescent holographic microscope-based geometric phase lens is proposed. This system allows for wide-field, 3D fluorescence holographic imaging, and edge-enhancement from the reconstruction of only one complex-valued hologram. Experiments demonstrate the effectiveness of our method in imaging biological samples, with improved resolution and signal-to-noise ratio. Furthermore, its simplicity and convenience make it easily compatible with existing optical microscope setups, making it a powerful tool for observing biological samples and detecting industrial defects..
Photonics Research
- Publication Date: Nov. 01, 2024
- Vol. 12, Issue 11, 2703 (2024)
Transport-of-intensity differential phase contrast imaging: defying weak object approximation and matched-illumination condition
Jingfan Wang, Xing Zhao, Yan Wang, and Da Li
Quantitative phase imaging (QPI) has emerged as a promising label-free imaging technique with growing importance in biomedical...show moreQuantitative phase imaging (QPI) has emerged as a promising label-free imaging technique with growing importance in biomedical research, optical metrology, materials science, and other fields. Partially coherent illumination provides resolution twice that of the coherent diffraction limit, along with improved robustness and signal-to-noise ratio, making it an increasingly significant area of study in QPI. Partially coherent QPI, represented by differential phase contrast (DPC), linearizes the phase-to-intensity transfer process under the weak object approximation (WOA). However, the nonlinear errors caused by WOA in DPC can lead to phase underestimation. Additionally, DPC requires strict matching of the illumination numerical aperture (NA) to ensure the complete transmission of low-frequency information. This necessitates precise alignment of the optical system and limits the flexible use of objective and illumination. In this study, the applicability of the WOA under different coherence parameters is explored, and a method to defy WOA by reducing the illumination NA is proposed. The proposed method uses the transport-of-intensity equation through an additional defocused intensity image to recover the lost low-frequency information due to illumination mismatch, without requiring any iterative procedure. This method overcomes the limitations of DPC being unable to recover large phase objects and does not require the strict illumination matching conditions. The accurate quantitative morphological characterization of customized artifact and microlens arrays that do not satisfy WOA under non-matched-illumination conditions demonstrated the precise quantitative capability of the proposed method and its excellent performance in the field of measurement. Meanwhile, the phase retrieval of tongue slices and oral epithelial cells demonstrated its application potential in the biomedical field. The ability to accurately recover phase under a concise and implementable optical setup makes it a promising solution for widespread application in various label-free imaging domains..
Photonics Research
- Publication Date: Nov. 01, 2024
- Vol. 12, Issue 11, 2712 (2024)
Instrumentation and Measurements
Reducing statistical noise in frequency ratio measurement between Ca+ and Sr optical clocks with a frequency-synthesized local oscillator from a Sr optical clock
Haosen Shi, Bingkun Lu, Huaqing Zhang, Ruming Hu... and Longsheng Ma|Show fewer author(s)
Optical frequency ratio measurement between optical atomic clocks is essential to precision measurement as well as the redefinition of...show moreOptical frequency ratio measurement between optical atomic clocks is essential to precision measurement as well as the redefinition of the second. Currently, the statistical noise in frequency ratio measurement of most ion clocks is limited by the frequency instability of ion clocks. In this work, we reduce the statistical noise in the frequency ratio measurement between a transportable
Photonics Research
- Publication Date: Nov. 01, 2024
- Vol. 12, Issue 11, 2741 (2024)
Integrated Optics
Integrated photonic modular arithmetic processor
Yuepeng Wu, Hongxiang Guo, Bowen Zhang, Jifang Qiu... and Jian Wu|Show fewer author(s)
Integrated photonic computing has emerged as a promising approach to overcome the limitations of electronic processors in the post...show moreIntegrated photonic computing has emerged as a promising approach to overcome the limitations of electronic processors in the post-Moore era. However, present integrated photonic computing systems face challenges in achieving high-precision calculations, consequently limiting their potential applications, and their heavy reliance on analog-to-digital (AD) and digital-to-analog (DA) conversion interfaces undermines their performance. Here we propose an innovative photonic computing architecture featuring scalable calculation precision and, to our knowledge, a novel photonic conversion interface. By leveraging the residue number system (RNS) theory, the high-precision calculation is decomposed into multiple low-precision modular arithmetic operations executed through optical phase manipulation. Those operations directly interact with the digital system via our proposed optical digital-to-phase converter (ODPC) and phase-to-digital converter (OPDC). Through experimental demonstrations, we showcase a calculation precision of 9 bits and verify the feasibility of the ODPC/OPDC photonic interface. This approach paves the path towards liberating photonic computing from the constraints imposed by limited precision and AD/DA converters..
Photonics Research
- Publication Date: Nov. 01, 2024
- Vol. 12, Issue 11, 2676 (2024)
Interview
Lan Yang
This interview article features Professor Yidong Huang, a pioneering scientist and exceptional community leader in optoelectronics, whose...show moreThis interview article features Professor Yidong Huang, a pioneering scientist and exceptional community leader in optoelectronics, whose contributions extend beyond academia into entrepreneurship and leadership. As part of a new series launched by Photonics Research, this interview aims to highlight the journeys and achievements of prominent women in optics and photonics. Through insightful reflections, Professor Huang discusses her scientific journey, including the challenges she encountered, her proudest achievements, and her vision for the future of optoelectronics. She also shares advice for young researchers, strategies for maintaining work–life balance, and experiences with technology transfer from academia to industry..
Photonics Research
- Publication Date: Oct. 30, 2024
- Vol. 12, Issue 11, 2521 (2024)
Lasers and Laser Optics
III-V-on-Si3N4 widely tunable narrow-linewidth laser based on micro-transfer printing | Spotlight on Optics
Biwei Pan, Jerome Bourderionnet, Vincent Billault, Guenole Dande... and Gunther Roelkens|Show fewer author(s)
Leveraging its superior waveguide properties, silicon-nitride (Si3N4) photonics is emerging to expand the applications of photonic...show moreLeveraging its superior waveguide properties, silicon-nitride (
Photonics Research
- Publication Date: Oct. 30, 2024
- Vol. 12, Issue 11, 2508 (2024)
Monolithic dispersion engineered mid-infrared quantum cascade laser frequency comb
Dapeng Wu, Yu Ma, Yongqiang Sun, Ruixin Huang... and Quanyong Lu|Show fewer author(s)
The high-power quantum cascade laser (QCL) frequency comb capable of room temperature operation is of great interest to high-precision...show moreThe high-power quantum cascade laser (QCL) frequency comb capable of room temperature operation is of great interest to high-precision measurement and low-noise molecular spectroscopy. While a significant amount of research is devoted to the longwave spectral range, shortwave 3–5 μm QCL combs are still relatively underdeveloped due to the excessive material dispersion. In this work, we propose a monolithic integrated multimode waveguide scheme for effective dispersion engineering and high-power-efficiency operation. Over watt-level output power at room temperature with a wall plug efficiency of 7% and robust dispersion reduction is achieved from a quantum cascade laser frequency comb at a wavelength approximately
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2566 (2024)
Nanophotonics and Photonic Crystals
Tailoring directional chiral emission from molecules coupled to extrinsic chiral quasi-bound states in the continuum | Editors' Pick
Minpeng Liang, Lucio Claudio Andreani, Anton Matthijs Berghuis, José Luis Pura... and Jaime Gómez Rivas|Show fewer author(s)
We investigate the chiral emission from non-chiral molecules coupled to metasurfaces with a unit cell formed by dimers of detuned and...show moreWe investigate the chiral emission from non-chiral molecules coupled to metasurfaces with a unit cell formed by dimers of detuned and displaced Si nanodisks. The detuning and displacement lead to the formation of narrow modes, known as quasi-bound states in the continuum (Q-BICs), with different electric and magnetic characteristics. The dispersion and character of the modes are explained by using the guided-mode expansion method and finite-element simulations. The coupling between these modes leads to an extrinsic chiral response with large circular dichroism for defined energies and wavevectors. When the lattice constant of the metasurface is changed, the dispersion of the extrinsic chiral Q-BICs can be tuned and the emission properties of a thin film of dye molecules on top of the metasurface are modified. In particular, we observe strongly directional and circularly polarized emission from the achiral dye molecules with a degree of circular polarization reaching 0.8 at the wavelengths defined by the dispersion of the Q-BICs. These results could enable the realization of compact light sources with a large degree of circular polarization for applications in displays, optical recording, or optical communication..
Photonics Research
- Publication Date: Oct. 11, 2024
- Vol. 12, Issue 11, 2462 (2024)
Sensitivity enhancement of guided mode resonance sensors under oblique incidence
Liang Guo, Lei Xu, and Liying Liu
The sensitivity of guided mode resonance (GMR) sensors is significantly enhanced under oblique incidence. Here in this work, we developed a...show moreThe sensitivity of guided mode resonance (GMR) sensors is significantly enhanced under oblique incidence. Here in this work, we developed a simplified theoretical model to provide analytical solutions and reveal the mechanism of sensitivity enhancement. We found that the sensitivity under oblique incidence consists of two contributions, the grating sensitivity and waveguide sensitivity, while under normal incidence, only waveguide sensitivity exists. When the two contributions are constructively superposed, as in the case of positive first order diffraction of the grating, the total sensitivity is enhanced. On the other hand, when the two parts are destructively superposed, as in the case of negative first order diffraction, the total sensitivity decreases. The findings are further supported by FDTD numerical calculations and proof-of-concept experiments..
Photonics Research
- Publication Date: Nov. 01, 2024
- Vol. 12, Issue 11, 2667 (2024)
Nonlinear Optics
Trans-spectral transfer of spatio-temporal optical Ferris wheel with nonlinear wave mixing | On the Cover
Sandan Wang, Jinpeng Yuan, Lirong Wang, Liantuan Xiao, and Suotang Jia
The trans-spectral manipulation of spatio-temporal structured light, characterized by dynamic inhomogeneous trajectories and a unique...show moreThe trans-spectral manipulation of spatio-temporal structured light, characterized by dynamic inhomogeneous trajectories and a unique nature in the space–time domain, opens myriad possibilities for high-dimensional optical communication in the ultraviolet band. Here, we experimentally demonstrate the high-performance transfer of the spatio-temporal optical Ferris wheel beam from near-infrared to blue–violet wavelengths. Owing to the energy conservation and momentum conservation mechanism, the 420 nm output signal beam accurately retains the spatio-temporal characteristics of the 776 nm input probe optical Ferris wheel beam, facilitated by the 780 nm Gaussian pump beam. The identical multi-petal intensity profiles confirm the successful transfer of spatial characteristics from the input probe to the output signal beams. The fully synchronized rotation velocities and directions of the probe and signal beams demonstrate the precise transfer of temporal characteristics, achieving approximately 98% conversion accuracy. This work enables efficient information transfer across different wavelength bands and offers a promising approach for achieving high-dimensional quantum communication..
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2559 (2024)
Linear and nonlinear coupling of light in twin-resonators with Kerr nonlinearity
Arghadeep Pal, Alekhya Ghosh, Shuangyou Zhang, Lewis Hill... and Pascal Del’Haye|Show fewer author(s)
Nonlinear effects in microresonators are efficient building blocks for all-optical computing and telecom systems. With the latest...show moreNonlinear effects in microresonators are efficient building blocks for all-optical computing and telecom systems. With the latest advances in microfabrication, coupled microresonators are used in a rapidly growing number of applications. In this work, we investigate the coupling between twin-resonators in the presence of Kerr nonlinearity. We use an experimental setup with controllable coupling between two high-Q resonators and discuss the effects caused by the simultaneous presence of linear and nonlinear coupling between the optical fields. Linear-coupling-induced mode splitting is observed at low input powers, with the controllable coupling leading to a tunable mode splitting. At high input powers, the hybridized resonances show spontaneous symmetry breaking (SSB) effects, in which the optical power is unevenly distributed between the resonators. Our experimental results are supported by a detailed theoretical model of nonlinear twin-resonators. With the recent interest in coupled resonator systems for neuromorphic computing, quantum systems, and optical frequency comb generation, our work provides important insights into the behavior of these systems at high circulating powers..
Photonics Research
- Publication Date: Nov. 01, 2024
- Vol. 12, Issue 11, 2733 (2024)
Optical and Photonic Materials
Para-phenylenediamine Schiff base: highly fluorescent photostable solid-state organic dye
Hani Barhum, Mohammad Attrash, Inga Brice, Vyacheslav V. Kim... and Pavel Ginzburg|Show fewer author(s)
Schiff bases derived from the condensation of primary amines with aldehydes, such as para-phenylenediamine with salicylaldehyde, exhibit...show moreSchiff bases derived from the condensation of primary amines with aldehydes, such as para-phenylenediamine with salicylaldehyde, exhibit unique optical and structural properties ideal for photonic applications. This study synthesizes such a Schiff base, revealing its properties through detailed
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2639 (2024)
Optical Devices
Metamaterial-inspired infrared electrochromic devices with wideband microwave absorption for multispectral camouflage
Zhen Meng, Dongqing Liu, Jiafu Wang, Yongqiang Pang... and Haifeng Cheng|Show fewer author(s)
Infrared (IR) electrochromic devices, capable of dynamically controlling thermal radiation, hold promising applications in adaptive...show moreInfrared (IR) electrochromic devices, capable of dynamically controlling thermal radiation, hold promising applications in adaptive camouflage. However, the strong microwave reflective properties inherent in the device’s electrodes present a significant challenge, rendering them susceptible to radar detection and weakening their camouflage effect. Inspired by the remarkable electromagnetic control capabilities of metamaterials, the integration of frequency selective surfaces into IR electrochromic devices is proposed to address this multispectral compatibility challenge. The designed integrated metadevices simultaneously exhibit large and reversible IR emissivity tunability (
Photonics Research
- Publication Date: Oct. 10, 2024
- Vol. 12, Issue 11, 2435 (2024)
Formation of quasi-bound states in the continuum in a single deformed microcavity
Shuai Liu, Bo-Han Wu, Jeffrey Huang, and Zheshen Zhang
Bound states in the continuum (BICs) hold significant promise in manipulating electromagnetic fields and reducing losses in optical...show moreBound states in the continuum (BICs) hold significant promise in manipulating electromagnetic fields and reducing losses in optical structures, leading to advancements in fundamental research and practical applications. Despite their observation in various optical systems, the behavior of BIC in whispering-gallery-modes (WGMs) optical microcavities, essential components of photonic integrated chips, has yet to be thoroughly explored. In this study, we propose and experimentally identify a robust mechanism for generating quasi-BIC in a single deformed microcavity. By introducing boundary deformations, we construct stable unidirectional radiation channels as leaking continuum shared by different resonant modes and experimentally verify their external strong mode coupling. This results in drastically suppressed leaking loss of one originally long-lived resonance, manifested as more than a threefold enhancement of its quality (
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2651 (2024)
Anisotropic programmable metasurfaces with individually controllable 2-bit elements
Xin Ge Zhang, Qiu Cen Hu, Qi Yang Li, Zhixiang Huang... and Wei Xiang Jiang|Show fewer author(s)
Programmable metasurfaces capable of manipulating electromagnetic (EM) waves in real time provide new opportunities for...show moreProgrammable metasurfaces capable of manipulating electromagnetic (EM) waves in real time provide new opportunities for various exciting applications. However, most previous programmable metasurfaces only work in a single polarization mode and their elements are controlled in a whole or one-dimensional way, which limits functionality and adaptability to complex environments. Here, an anisotropic programmable metasurface with individually controllable elements is proposed to realize real-time and independent dual-polarized EM control in the two-dimension direction. The anisotropic metasurface element is designed using the ingenious cross-over resonant structure integrated with two sets of varactors to achieve 2-bit phase modulation in the respective polarization direction. As a demonstration, an anisotropic programmable metasurface prototype with
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2660 (2024)
Physical Optics
Low-gain generalized PT symmetry for electromagnetic impurity-immunity via non-Hermitian doped zero-index materials
Cuiping Liu, Dongyang Yan, Baoyin Sun, Yadong Xu... and Jie Luo|Show fewer author(s)
Parity-time-symmetric (PT-symmetric) metasurfaces exhibit a plethora of fascinating exceptional-point-induced phenomena, including...show moreParity-time-symmetric (PT-symmetric) metasurfaces exhibit a plethora of fascinating exceptional-point-induced phenomena, including unidirectional negative refraction and electromagnetic impurity-immunity. However, practical realization of these effects is often impeded by the high demand for gain metasurfaces (gain tangent
Photonics Research
- Publication Date: Oct. 10, 2024
- Vol. 12, Issue 11, 2424 (2024)
Dynamic phase transition region in electrically injected PT-symmetric lasers
Yang Chen, Yufei Wang, Jingxuan Chen, Ting Fu... and Wanhua Zheng|Show fewer author(s)
Research on parity-time (PT) symmetry and exceptional points in non-Hermitian laser systems has been extensively conducted....show moreResearch on parity-time (PT) symmetry and exceptional points in non-Hermitian laser systems has been extensively conducted. However, in practical electrically injected PT-symmetric lasers, the frequency detuning and linewidth enhancement factor of the laser can influence the symmetry breaking of the system in another dimension. We find that the previous exceptional point now transforms into a dynamic phase transition region, where the states are temporally unstable, indicating the occurrence of multimode oscillation. The relative phase and field amplitude ratio in this region also exhibit many novel phenomena indicating its instability. This region can be manipulated by adjusting the coupling strength between adjacent waveguides and the pumping intensity in the loss waveguide. Experimentally, we characterize the near-field, far-field, and spectrum of several structures, and the results validate our theoretical model. This work elucidates the dynamic process and phase transition process of electrically injected PT-symmetric lasers, providing support for the practical application of PT-symmetric lasers..
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2539 (2024)
Measuring the OAM spectrum of a fractional helical beam in a single shot
Tushar Sarkar, Jiapeng Cai, Xiang Peng, and Wenqi He
We propose and experimentally demonstrate a new technique, to our knowledge, to precisely measure the orbital angular momentum (OAM)...show moreWe propose and experimentally demonstrate a new technique, to our knowledge, to precisely measure the orbital angular momentum (OAM) spectrum of the fractional helical beam in a single shot. This is realized using a single-path interferometer scheme combined with space division multiplexing and polarization phase-shifting. Such a combination enables the single-shot recording of multiple phase-shifted interferograms, which leads to extracting the phase profile of the incident fractional helical beam. Furthermore, by adopting an orthogonal projection method, this measured phase is utilized to evaluate the corresponding OAM spectrum. To test the efficacy, a set of simulations and experiments for different fractional helical beams is demonstrated. The proposed method shows enormous potential to characterize the OAM spectrum in real time..
Photonics Research
- Publication Date: Nov. 01, 2024
- Vol. 12, Issue 11, 2726 (2024)
Quantum Optics
Robust continuous-variable quantum key distribution in the finite-size regime
Yuehan Xu, Tao Wang, Xiaojuan Liao, Yingming Zhou... and Guihua Zeng|Show fewer author(s)
Quantum key distribution (QKD) has been proven to be theoretically unconditionally secure. However, any theoretical security proof...show moreQuantum key distribution (QKD) has been proven to be theoretically unconditionally secure. However, any theoretical security proof relies on certain assumptions. In QKD, the assumption in the theoretical proof is that the security of the protocol is considered under the asymptotic case where Alice and Bob exchange an infinite number of signals. In the continuous-variable QKD (CV-QKD), the finite-size effect imposes higher requirements on block size and excess noise control. However, the local local oscillator (LLO) CV-QKD system cannot be considered time-invariant under long blocks, especially in cases of environmental disturbances. Thus, we propose an LLO CV-QKD scheme with time-variant parameter estimation and compensation. We first establish an LLO CV-QKD theoretical model under the temporal modes of continuous-mode states. Then, a robust method is used to compensate for arbitrary frequency shift and arbitrary phase drift in CV-QKD systems with longer blocks, which cannot be achieved under traditional time-invariant parameter estimation. Besides, the digital signal processing method predicated on high-speed reference pilots can achieve a time complexity of
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2549 (2024)
Silicon Photonics
112 Gbps CMOS-compatible waveguide germanium photodetector for the 2 μ m wavelength band with a 3.64 A/W response
Yupeng Zhu, Zhi Liu, Zhipeng Liu, Yiling Hu... and Buwen Cheng|Show fewer author(s)
The 2 μm wavelength band emerges as a promising candidate for the next communication window to enhance the transmission capacity of...show moreThe 2 μm wavelength band emerges as a promising candidate for the next communication window to enhance the transmission capacity of data. A high-responsivity and high-speed photodetector operating at 2 μm is crucial for the 2-μm-wavelength-band communication system. Here, we present an on-chip waveguide-coupled germanium photodetector with remarkably high responsivity and data-receiving rate, employing subbandgap light absorption and avalanche multiplication. The device is designed with an ingenious and simple asymmetric lateral p-i-n junction structure and fabricated through a standard CMOS process by a commercial factory. It has a responsivity of 3.64 A/W and a maximum bandwidth of 50 GHz at 2 μm wavelength. For the first time, to the best of our knowledge, an optical receiving rate of up to 112 Gbps is demonstrated at 2 μm, verifying its feasibility in a high-speed 2-μm-band communication system. To the best of our knowledge, the proposed device stands out as the fastest photodiode with the highest responsivity among all group III-V and group IV photodetectors working in the 2 μm wavelength band..
Photonics Research
- Publication Date: Oct. 31, 2024
- Vol. 12, Issue 11, 2633 (2024)
Scalable parallel photonic processing unit for various neural network accelerations
Shiyin Du, Jun Zhang, Hao Ouyang, Zilong Tao... and Tian Jiang|Show fewer author(s)
In recent years, integrated optical processing units (IOPUs) have demonstrated advantages in energy efficiency and computational speed for...show moreIn recent years, integrated optical processing units (IOPUs) have demonstrated advantages in energy efficiency and computational speed for neural network inference applications. However, limited by optical integration technology, the practicality and versatility of IOPU face serious challenges. In this work, a scalable parallel photonic processing unit (SPPU) for various neural network accelerations based on high-speed phase modulation is proposed and implemented on a silicon-on-insulator platform, which supports parallel processing and can switch between multiple computational paradigms simply and without latency to infer different neural network structures, enabling to maximize the utility of on-chip components. The SPPU adopts a scalable and process-friendly architecture design, with a preeminent photonic-core energy efficiency of 0.83 TOPS/W, two to ten times higher than existing integrated solutions. In the proof-of-concept experiment, a convolutional neural network (CNN), a residual CNN, and a recurrent neural network (RNN) are all implemented on our photonic processor to handle multiple tasks of handwritten digit classification, signal modulation format recognition, and review emotion recognition. The SPPU achieves multi-task parallel processing capability, serving as a promising and attractive research route to maximize the utility of on-chip components under the constraints of integrated technology, which helps to make IOPU more practical and universal..
Photonics Research
- Publication Date: Nov. 01, 2024
- Vol. 12, Issue 11, 2691 (2024)
Surface Optics and Plasmonics
High-efficiency terahertz surface plasmon metacoupler empowered by bilayer bright–dark mode coupling
Zhibo Yao, Xinyao Yuan, Yuanhao Lang, Fu Li... and Jiaguang Han|Show fewer author(s)
Conversion from free-space waves to surface plasmons has been well studied as a key aspect of plasmonics. In particular, efficient...show moreConversion from free-space waves to surface plasmons has been well studied as a key aspect of plasmonics. In particular, efficient coupling and propagation of surface plasmons via phase gradient metasurfaces are of great current research interest. Hereby, we demonstrate a terahertz metacoupler based on a bilayer bright–dark mode coupling structure attaining near-perfect conversion efficiency (exceeding 95%) without considering absorption loss of the materials and maintaining a high conversion level even when the area of the excitation region changes. To validate our design, a fabricated metacoupler was assessed by scanning near-field terahertz microscopy. Our findings could pave the way for developing high-performance plasmonic devices encompassing ultra-thin and compact functional devices for a diverse range of applications, especially within the realm of high-speed terahertz communications..
Photonics Research
- Publication Date: Oct. 30, 2024
- Vol. 12, Issue 11, 2495 (2024)
About the Cover
The image illustrates the principle of the high-performance transfer of the spatio-temporal structured light from near-infrared to blue-violet wavelengths through nonlinear wave mixing in atomic vapor. It has the potential to drive significant advancements in high-dimensional quantum communication and super-resolution imaging. See Sandan Wang et al., pp. 2559.
© Copyright 2018-2021 | Chinese Laser Press. All Rights Reserved 沪ICP备15018463号-20