Contents
2023
Volume: 11 Issue 5
24 Article(s)
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OPTICAL METASURFACES: FUNDAMENTALS AND APPLICATIONS
Optical metasurfaces: fundamentals and applications
Thomas Pertsch, Shumin Xiao, Arka Majumdar, and Guixin Li
Optical metasurfaces are currently an important research area all around the world because of their wide application opportunities in imaging, wavefront engineering, nonlinear optics, quantum information processing, just to name a few. The feature issue “Optical Metasurfaces: Fundamentals and Applications” in Photonics Research allows for archival publication of the most recent works in optical metasurface and provides for broad dissemination in the photonics community.Optical metasurfaces are currently an important research area all around the world because of their wide application opportunities in imaging, wavefront engineering, nonlinear optics, quantum information processing, just to name a few. The feature issue “Optical Metasurfaces: Fundamentals and Applications” in Photonics Research allows for archival publication of the most recent works in optical metasurface and provides for broad dissemination in the photonics community..
Photonics Research
- Publication Date: Apr. 21, 2023
- Vol. 11, Issue 5, OMFA1 (2023)
Cascaded parametric amplification based on spatiotemporal modulations
Qianru Yang, Hao Hu, Xiaofeng Li, and Yu Luo
Active devices have drawn considerable attention owing to their powerful capabilities to manipulate electromagnetic waves. Fast and periodic modulation of material properties is one of the key obstacles to the practical impleshow moreActive devices have drawn considerable attention owing to their powerful capabilities to manipulate electromagnetic waves. Fast and periodic modulation of material properties is one of the key obstacles to the practical implementation of active metamaterials and metasurfaces. In this study, to circumvent this limitation, we employ a cascaded phase-matching mechanism to amplify signals through spatiotemporal modulation of permittivity. Our results show that the energy of the amplified fundamental mode can be efficiently transferred to that of the high harmonic components if the spatiotemporal modulation travels at the same speed as the signals. This outstanding benefit enables a low-frequency pump to excite parametric amplification. The realization of cascaded parametric amplification is demonstrated by finite-difference time-domain (FDTD) simulations and analytical calculations based on the Bloch–Floquet theory. We find that the same lasing state can always be excited by an incidence at different harmonic frequencies. The spectral and temporal responses of the space-time modulated slab strongly depend on the modulation length, modulation strength, and modulation velocity. Furthermore, the cascaded parametric oscillators composed of a cavity formed by photonic crystals are presented. The lasing threshold is significantly reduced by the cavity resonance. Finally, the excitation of cascaded parametric amplification relying on the Si-waveguide platform is demonstrated. We believed that the proposed mechanism provides a promising opportunity for the practical implementation of intense amplification and coherent radiation based on active metamaterials..
Photonics Research
- Publication Date: Apr. 21, 2023
- Vol. 11, Issue 5, B125 (2023)
Reviews
Optoelectronics
Review on metal halide perovskite-based optoelectronic synapses
Xitong Hong, Xingqiang Liu, Lei Liao, and Xuming Zou
With the progress of both photonics and electronics, optoelectronic synapses are considered potential candidates to challenge the von Neumann bottleneck and the field of visual bionics in the era of big data. They are also reshow moreWith the progress of both photonics and electronics, optoelectronic synapses are considered potential candidates to challenge the von Neumann bottleneck and the field of visual bionics in the era of big data. They are also regarded as the basis for integrated artificial neural networks (ANNs) owing to their flexible optoelectronic tunable properties such as high bandwidth, low power consumption, and high-density integration. Over the recent years, following the emergence of metal halide perovskite (MHP) materials possessing fascinating optoelectronic properties, novel MHP-based optoelectronic synaptic devices have been exploited for numerous applications ranging from artificial vision systems (AVSs) to neuromorphic computing. Herein, we briefly review the application prospects and current status of MHP-based optoelectronic synapses, discuss the basic synaptic behaviors capable of being implemented, and assess their feasibility to mimic biological synapses. Then, we focus on the two-terminal optoelectronic synaptic memristors and three-terminal transistor synaptic phototransistors (SPTs), the two essential apparatus structures for optoelectronic synapses, expounding their basic features and operating mechanisms. Finally, we summarize the recent applications of optoelectronic synapses in neuromorphic systems, including neuromorphic computing, high-order learning behaviors, and neuromorphic vision systems, outlining their potential opportunities and future development directions as neuromorphic devices in the field of artificial intelligence (AI)..
Photonics Research
- Publication Date: Apr. 28, 2023
- Vol. 11, Issue 5, 787 (2023)
Research Articles
Editorials
Lan Yang
The editor-in-chief of Photonics Research announces the journal’s 10-year anniversary, which takes place in 2023 and reports on new initiatives for the journal.
The editor-in-chief of
Photonics Research
- Publication Date: Apr. 28, 2023
- Vol. 11, Issue 5, ED1 (2023)
Imaging Systems, Microscopy, and Displays
Structured illumination-based super-resolution live-cell quantitative FRET imaging
Zewei Luo, Ge Wu, Mengting Kong, Zhi Chen... and Tongsheng Chen|Show fewer author(s)
Förster resonance energy transfer (FRET) microscopy provides unique insight into the functionality of biological systems via imaging the spatiotemporal interactions and functional state of proteins. Distinguishing FRET signalshow moreFörster resonance energy transfer (FRET) microscopy provides unique insight into the functionality of biological systems via imaging the spatiotemporal interactions and functional state of proteins. Distinguishing FRET signals from sub-diffraction regions requires super-resolution (SR) FRET imaging, yet is challenging to achieve from living cells. Here, we present an SR FRET method named SIM-FRET that combines SR structured illumination microscopy (SIM) imaging and acceptor sensitized emission FRET imaging for live-cell quantitative SR FRET imaging. Leveraging the robust co-localization prior of donor and accepter during FRET, we devised a mask filtering approach to mitigate the impact of SIM reconstruction artifacts on quantitative FRET analysis. Compared to wide-field FRET imaging, SIM-FRET provides nearly twofold spatial resolution enhancement of FRET imaging at sub-second timescales and maintains the advantages of quantitative FRET analysis in vivo. We validate the resolution enhancement and quantitative analysis fidelity of SIM-FRET signals in both simulated FRET models and live-cell FRET-standard construct samples. Our method reveals the intricate structure of FRET signals, which are commonly distorted in conventional wide-field FRET imaging..
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 887 (2023)
Integrated Optics
Photon propagation control on laser-written photonic chips enabled by composite waveguides
Ze-Zheng Li, Zhen-Nan Tian, Zhong-Tian Li, Yang Ouyang... and Hong-Bo Sun|Show fewer author(s)
Femtosecond laser direct writing (FsLDW) three-dimensional (3D) photonic integrated circuits (PICs) can realize arbitrary arrangement of waveguide arrays and coupling devices. Thus, they are capable of directly constructing ashow moreFemtosecond laser direct writing (FsLDW) three-dimensional (3D) photonic integrated circuits (PICs) can realize arbitrary arrangement of waveguide arrays and coupling devices. Thus, they are capable of directly constructing arbitrary Hamiltonians and performing specific computing tasks crucial in quantum simulation and computation. However, the propagation constant
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 829 (2023)
Lasers and Laser Optics
Widely tunable continuous-wave visible and mid-infrared light generation based on a dual-wavelength switchable and tunable random Raman fiber laser | Editors' Pick
Han Wu, Weizhe Wang, Bo Hu, Yang Li... and Houkun Liang|Show fewer author(s)
Nonlinear frequency conversion of wavelength agile and high-power random fiber lasers can provide a promising way to generate continuous-wave (CW) visible and mid-infrared (MIR) light with unique properties such as the continshow moreNonlinear frequency conversion of wavelength agile and high-power random fiber lasers can provide a promising way to generate continuous-wave (CW) visible and mid-infrared (MIR) light with unique properties such as the continuous modeless spectrum, low temporal/spatial coherence, and high temporal stability. Here, we report a dual-wavelength switchable and tunable random Raman fiber laser (RRFL) based on a phosphosilicate fiber that has two Raman gain peaks for the first time and demonstrate its superior capability to generate widely tunable CW visible and mid-infrared light via nonlinear frequency conversions. By using the combination of a tunable pump and two tunable gratings in Littrow configuration that can provide separated point feedback for the two Stokes wavelengths corresponding to silica- and phosphorus-related Raman peaks, the spectrum of an RRFL can be flexibly manipulated for the aim of nonlinear frequency conversions, including single-wavelength tunable emission at the 1.1 μm or 1.2 μm band for second-harmonic generation (SHG), dual-wavelength simultaneously tunable emission at the 1.1 μm and 1.2 μm bands for the sum-frequency generation (SFG), and dual-wavelength separation tunable emission for difference-frequency generation (DFG). As a result, with the combination of SHG and SFG in a periodically poled lithium niobate crystal array, we experimentally demonstrate the broadest tuning range (560–630 nm) of visible light generated from an RRFL, to the best of our knowledge. The tunable MIR light in the range of 10.7–12.3 μm is also demonstrated through DFG of an RRFL operating in separation tunable dual-wavelength emission mode in a
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 808 (2023)
Medical Optics and Biotechnology
Two-beam phase correlation spectroscopy: a label-free holographic method to quantify particle flow in biofluids | On the Cover
Lan Yu, Yu Wang, Yang Wang, Kequn Zhuo... and Peng Gao|Show fewer author(s)
We introduce two-beam phase correlation spectroscopy (2B-ΦCS) as a label-free technique to measure the dynamics of flowing particles; e.g., in vitro or in vivo blood flow. 2B-ΦCS combines phase imaging with correlation spectrshow moreWe introduce two-beam phase correlation spectroscopy (
Photonics Research
- Publication Date: Apr. 28, 2023
- Vol. 11, Issue 5, 757 (2023)
Collagen fiber anisotropy characterization by polarized photoacoustic imaging for just-in-time quantitative evaluation of burn severity
Zhenhui Zhang, Wei Chen, Dandan Cui, Jie Mi... and Yujiao Shi|Show fewer author(s)
Just-in-time burn severity assessment plays a vital role in burn treatment and care. However, it is still difficult to quantitatively and promptly evaluate burn severity by existing medical imaging methods via initial burn deshow moreJust-in-time burn severity assessment plays a vital role in burn treatment and care. However, it is still difficult to quantitatively and promptly evaluate burn severity by existing medical imaging methods via initial burn depth measurement since burn wounds are usually dynamically developed. As an elastic skeleton of skin, the degree of conformational changes of collagen fibers caused by overheating can reflect the burn severity in a timelier manner. Herein, the polarized photoacoustic technique (PPAT) for just-in-time quantitative evaluation of burn severity via collagen fiber anisotropy assessment is proposed. First, phantom experiments demonstrate the ability of PPAT for deep imaging in a transport mean free path and accurately quantify changes in microstructural order by thermal damage. Then, the Pearson correlation coefficient of the PPAT in assessing burn severity is shown to be up to 0.95, validated by burn skin samples. The PPAT provides a just-in-time quantitative strategy for burn severity evaluation..
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 817 (2023)
Nanophotonics and Photonic Crystals
Self-design of arbitrary polarization-control waveplates via deep neural networks | Spotlight on Optics
Zhengchang Liu, Zhibo Dang, Zhixin Liu, Yu Li... and Zheyu Fang|Show fewer author(s)
The manipulation of polarization states beyond the optical limit presents advantages in various applications. Considerable progress has been made in the design of meta-waveplates for on-demand polarization transformation, reashow moreThe manipulation of polarization states beyond the optical limit presents advantages in various applications. Considerable progress has been made in the design of meta-waveplates for on-demand polarization transformation, realized by numerical simulations and parameter sweep methodologies. However, due to the limited freedom in these classical strategies, particular challenges arise from the emerging requirement for multiplex optical devices and multidimensional manipulation of light, which urge for a large number of different nanostructures with great polarization control capability. Here, we demonstrate a set of self-designed arbitrary wave plates with a high polarization conversion efficiency. We combine Bayesian optimization and deep neural networks to design perfect half- and quarter-waveplates based on metallic nanostructures, which experimentally demonstrate excellent polarization control functionalities with the conversion ratios of 85% and 90%. More broadly, we develop a comprehensive wave plate database consisting of various metallic nanostructures with high polarization conversion efficiency, accompanying a flexible tuning of phase shifts (
Photonics Research
- Publication Date: Apr. 12, 2023
- Vol. 11, Issue 5, 695 (2023)
Nonlinear Optics
Spatiotemporal mode decomposition of ultrashort pulses in linear and nonlinear graded-index multimode fibers | Editors' Pick
Mario Zitelli, Vincent Couderc, Mario Ferraro, Fabio Mangini... and Stefan Wabnitz|Show fewer author(s)
We develop a spatiotemporal mode decomposition technique to study the spatial and temporal mode power distribution of ultrashort pulses in long spans of graded-index multimode fiber, for different input laser conditions. We find that the beam mode power content in the dispersive pulse propagation regime can be described by the Bose–Einstein law, as a result of the process of power diffusion from linear and nonlinear mode coupling among nondegenerate mode groups. In the soliton regime, the output mode power distribution approaches the Rayleigh–Jeans law.We develop a spatiotemporal mode decomposition technique to study the spatial and temporal mode power distribution of ultrashort pulses in long spans of graded-index multimode fiber, for different input laser conditions. We find that the beam mode power content in the dispersive pulse propagation regime can be described by the Bose–Einstein law, as a result of the process of power diffusion from linear and nonlinear mode coupling among nondegenerate mode groups. In the soliton regime, the output mode power distribution approaches the Rayleigh–Jeans law..
Photonics Research
- Publication Date: Apr. 25, 2023
- Vol. 11, Issue 5, 750 (2023)
Optical and Photonic Materials
Multiband camouflage design with thermal management
Lehong Huang, Haochuan Li, Zhiguo Li, Wenbo Zhang... and Shiping Guo|Show fewer author(s)
Although the effective “stealth” of space vehicles is important, current camouflage designs are inadequate in meeting all application requirements. Here, a multilayer wavelength-selective emitter is demonstrated. It can realize visible light and dual-band mid-infrared camouflage with thermal control management in two application scenarios, with better effect and stronger radiation cooling capability, which can significantly improve the stealth and survivability of space vehicles in different environments. The selective emitter demonstrated in this paper has the advantages of simple structure, scalability, and ease of large-area fabrication, and has made a major breakthrough in driving multiband stealth technology from simulation research to physical verification and even practical application.Although the effective “stealth” of space vehicles is important, current camouflage designs are inadequate in meeting all application requirements. Here, a multilayer wavelength-selective emitter is demonstrated. It can realize visible light and dual-band mid-infrared camouflage with thermal control management in two application scenarios, with better effect and stronger radiation cooling capability, which can significantly improve the stealth and survivability of space vehicles in different environments. The selective emitter demonstrated in this paper has the advantages of simple structure, scalability, and ease of large-area fabrication, and has made a major breakthrough in driving multiband stealth technology from simulation research to physical verification and even practical application..
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 839 (2023)
Pseudospin-2 in photonic chiral borophene | Editors' Pick
Philip Menz, Haissam Hanafi, Daniel Leykam, Jörg Imbrock, and Cornelia Denz
Pseudospin is an angular momentum degree of freedom introduced in analogy to the real electron spin in the effective massless Dirac-like equation used to describe wave evolution at conical intersections such as the Dirac cones of graphene. Here, we study a photonic implementation of a chiral borophene allotrope hosting a pseudospin-2 conical intersection in its energy–momentum spectrum. The presence of this fivefold spectral degeneracy gives rise to quasiparticles with pseudospin up to ±2. We report on conical diffraction and pseudospin–orbit interaction of light in photonic chiral borophene, which, as a result of topological charge conversion, leads to the generation of highly charged optical phase vortices.Pseudospin is an angular momentum degree of freedom introduced in analogy to the real electron spin in the effective massless Dirac-like equation used to describe wave evolution at conical intersections such as the Dirac cones of graphene. Here, we study a photonic implementation of a chiral borophene allotrope hosting a pseudospin-2 conical intersection in its energy–momentum spectrum. The presence of this fivefold spectral degeneracy gives rise to quasiparticles with pseudospin up to
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 869 (2023)
Optical Devices
Biosensing with free space whispering gallery mode microlasers
Angela Capocefalo, Silvia Gentilini, Lorenzo Barolo, Paola Baiocco... and Neda Ghofraniha|Show fewer author(s)
Highly accurate biosensors for few or single molecule detection play a central role in numerous key fields, such as healthcare and environmental monitoring. In the last decade, laser biosensors have been investigated as proofshow moreHighly accurate biosensors for few or single molecule detection play a central role in numerous key fields, such as healthcare and environmental monitoring. In the last decade, laser biosensors have been investigated as proofs of concept, and several technologies have been proposed. We here propose a demonstration of polymeric whispering gallery microlasers as biosensors for detecting small amounts of proteins, down to 400 pg. They have the advantage of working in free space without any need for waveguiding for input excitation or output signal detection. The photonic microsensors can be easily patterned on microscope slides and operate in air and solution. We estimate the limit of detection up to 148 nm/RIU for three different protein dispersions. In addition, the sensing ability of passive spherical resonators in the presence of dielectric nanoparticles that mimic proteins is described by massive ab initio numerical simulations..
Photonics Research
- Publication Date: Apr. 25, 2023
- Vol. 11, Issue 5, 732 (2023)
Electromagnetically induced transparency-like effect in a lithium niobate resonator via electronic control
Liu Yang, Yongyong Zhuang, Yifan Zhang, Yaojing Zhang... and Xiaoyong Wei|Show fewer author(s)
In this study, we theoretically proposed a method to achieve an electromagnetically induced transparency (EIT)-like effect in a whispering gallery mode resonator (WGMR) and experimentally validated the method in a lithium nioshow moreIn this study, we theoretically proposed a method to achieve an electromagnetically induced transparency (EIT)-like effect in a whispering gallery mode resonator (WGMR) and experimentally validated the method in a lithium niobate (LN) device. Benefitting from the electro-optic and inverse piezoelectric effects of the LN material, two modes of the LN WGMR that are close in frequency can be tuned at different tuning rates, resulting in EIT-like resonance lineshapes. By varying the electric field applied to the LN WGMR, the full dynamic of the EIT-like phenomenon can be precisely controlled. The experimental results agreed well with the calculations based on the coupled mode theory. Moreover, we observed a hysteresis resulting from the photorefractive effect of LN. We believe our proposed method and demonstrated devices offer a way to control an EIT-like effect, which could have potential applications in light storage, quantum information processing, and enhanced sensing techniques..
Photonics Research
- Publication Date: Apr. 28, 2023
- Vol. 11, Issue 5, 773 (2023)
Two-photon 3D printed spring-based Fabry–Pérot cavity resonator for acoustic wave detection and imaging
Heming Wei, Zhangli Wu, Kexuan Sun, Haiyan Zhang... and Sridhar Krishnaswamy|Show fewer author(s)
Optical fiber microresonators have attracted considerable interest for acoustic detection because of their compact size and high optical quality. Here, we have proposed, designed, and fabricated a spring-based Fabry–Pérot cavshow moreOptical fiber microresonators have attracted considerable interest for acoustic detection because of their compact size and high optical quality. Here, we have proposed, designed, and fabricated a spring-based Fabry–Pérot cavity microresonator for highly sensitive acoustic detection. We observed two resonator vibration modes: one relating to the spring vibration state and the other determined by the point-clamped circular plate vibration mode. We found that the vibration modes can be coupled and optimized by changing the structure size. The proposed resonator is directly 3D printed on an optical fiber tip through two-photon polymerization and is used for acoustic detection and imaging. The experiments show that the device exhibits a high sensitivity and low noise equivalent acoustic signal level of
Photonics Research
- Publication Date: Apr. 28, 2023
- Vol. 11, Issue 5, 780 (2023)
Hybrid metasurface using graphene/graphitic carbon nitride heterojunctions for ultrasensitive terahertz biosensors with tunable energy band structure
Haiyun Yao, Zhaoqing Sun, Lanju Liang, Xin Yan... and Jianquan Yao|Show fewer author(s)
Integrating novel materials is critical for the ultrasensitive, multi-dimensional detection of biomolecules in the terahertz (THz) range. Few studies on THz biosensors have used semiconductive active layers with tunable energshow moreIntegrating novel materials is critical for the ultrasensitive, multi-dimensional detection of biomolecules in the terahertz (THz) range. Few studies on THz biosensors have used semiconductive active layers with tunable energy band structures. In this study, we demonstrate three THz biosensors for detecting casein molecules based on the hybridization of the metasurface with graphitic carbon nitride, graphene, and heterojunction. We achieved low-concentration detection of casein molecules with a 3.54 ng/mL limit and multi-dimensional sensing by observing three degrees of variations (frequency shift, transmission difference, and phase difference). The favorable effect of casein on the conductivity of the semiconductive active layer can be used to explain the internal sensing mechanism. The incorporation of protein molecules changes the carrier concentration on the surface of the semiconductor active layer via the electrostatic doping effect as the concentration of positively charged casein grows, which alters the energy band structure and the conductivity of the active layer. The measured results indicate that any casein concentration can be distinguished directly by observing variations in resonance frequency, transmission value, and phase difference. With the heterojunction, the biosensor showed the highest response to the protein among the three biosensors. The Silvaco Atlas package was used to simulate the three samples’ energy band structure and carrier transport to demonstrate the benefits of the heterojunction for the sensor. The simulation results validated our proposed theoretical mechanism model. Our proposed biosensors could provide a novel approach for THz metasurface-based ultrasensitive biosensing technologies..
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 858 (2023)
Physical Optics
Nonreciprocal amplification transition in a topological photonic network
Mingsheng Tian, Fengxiao Sun, Kaiye Shi, Haitan Xu... and Wei Zhang|Show fewer author(s)
We studied the transport properties of a driven-dissipative photonic network, where multiple photonic cavities are coupled through a nonreciprocal bus with unidirectional transmission. For short-range coupling between the cavshow moreWe studied the transport properties of a driven-dissipative photonic network, where multiple photonic cavities are coupled through a nonreciprocal bus with unidirectional transmission. For short-range coupling between the cavities, the occurrence of nonreciprocal amplification can be linked to a topological phase transition of the underlying dynamic Hamiltonian. However, for long-range coupling, we show that the correspondence between the nonreciprocal amplification transition and the topological phase transition breaks down as the transition conditions deviate significantly from each other. We found the exact transition condition for nonreciprocal amplification, supported by analytical calculation and numerical simulation. We also investigated the stability, the crossover from short- to long-range coupling, and the bandwidth of the nonreciprocal amplification. Our work has potential applications in signal transmission and amplification, and also paves the way to study other topological and non-Hermitian systems with long-range coupling and nontrivial boundary effects..
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 852 (2023)
Silicon Photonics
Highly reconfigurable silicon integrated microwave photonic filter towards next-generation wireless communication
Zihan Tao, Yuansheng Tao, Ming Jin, Jun Qin... and Xingjun Wang|Show fewer author(s)
Integrated microwave photonic filters (IMPFs) are capable of offering unparalleled performances in terms of superb spectral fineness, broadband, and more importantly, the reconfigurability, which encounter the trend of the neshow moreIntegrated microwave photonic filters (IMPFs) are capable of offering unparalleled performances in terms of superb spectral fineness, broadband, and more importantly, the reconfigurability, which encounter the trend of the next-generation wireless communication. However, to achieve high reconfigurability, previous works should adopt complicated system structures and modulation formats, which put great pressure on power consumption and controlment, and, therefore, impede the massive deployment of IMPF. Here, we propose a streamlined architecture for a wideband and highly reconfigurable IMPF on the silicon photonics platform. For various practical filter responses, to avoid complex auxiliary devices and bias drift problems, a phase-modulated flexible sideband cancellation method is employed based on the intensity-consistent single-stage-adjustable cascaded-microring (ICSSA-CM). The IMPF exhibits an operation band extending to millimeter-wave (
Photonics Research
- Publication Date: Apr. 10, 2023
- Vol. 11, Issue 5, 682 (2023)
Ultra-low-loss multi-layer 8 × 8 microring optical switch
Xin Li, Wei Gao, Liangjun Lu, Jianping Chen, and Linjie Zhou
Microring-based optical switches are promising for wavelength-selective switching with the merits of compact size and low power consumption. However, the large insertion loss, the high fabrication, and the temperature sensitishow moreMicroring-based optical switches are promising for wavelength-selective switching with the merits of compact size and low power consumption. However, the large insertion loss, the high fabrication, and the temperature sensitivity hinder the scalability of silicon microring optical switch fabrics. In this paper, we utilize a three-dimensional (3D) microring-based optical switch element (SE) on a multi-layer
Photonics Research
- Publication Date: Apr. 12, 2023
- Vol. 11, Issue 5, 712 (2023)
Reconfigurable multichannel amplitude equalizer based on cascaded silicon photonic microrings
Changping Zhang, Shujun Liu, Hao Yan, Dajian Liu... and Daoxin Dai|Show fewer author(s)
A compact on-chip reconfigurable multichannel amplitude equalizer based on cascaded elliptical microrings is proposed and demonstrated experimentally. With the optimized structure of the elliptical microring with adiabaticallshow moreA compact on-chip reconfigurable multichannel amplitude equalizer based on cascaded elliptical microrings is proposed and demonstrated experimentally. With the optimized structure of the elliptical microring with adiabatically varied radii/widths, the average excess loss for each channel in the initialized state is measured to be less than 0.5 dB, while the attenuation dynamic range can be over 20 dB. Flexible tunability through the overlapping of the resonance peaks of adjacent wavelength-channels enables even higher attenuation dynamic ranges up to 50 dB. Leveraging the thermo-optic effect and fine wavelength-tuning linearity, precise tuning of the resonance peak can be implemented, enabling dynamic power equalization of each wavelength-channel in wavelength-division-multiplexing (WDM) systems and optical frequency combs. The proposed architecture exhibits excellent scalability, which can facilitate the development of long-haul optical transport networks and high-capacity neuromorphic computing systems, while improving the overall performance of optical signals in WDM-related systems..
Photonics Research
- Publication Date: Apr. 25, 2023
- Vol. 11, Issue 5, 742 (2023)
Equalization of a 10 Gbps IMDD signal by a small silicon photonics time delayed neural network
Emiliano Staffoli, Mattia Mancinelli, Paolo Bettotti, and Lorenzo Pavesi
A small 4-channel time-delayed complex perceptron is used as a silicon photonic neural network (PNN) device to compensate for chromatic dispersion in optical fiber links. The PNN device is experimentally tested with non-returshow moreA small 4-channel time-delayed complex perceptron is used as a silicon photonic neural network (PNN) device to compensate for chromatic dispersion in optical fiber links. The PNN device is experimentally tested with non-return-to-zero optical signals at 10 Gbps after propagation through up to 125 km optical fiber link. During the learning phase, a separation-loss function is optimized in order to maximally separate the transmitted levels of 0s from the 1s, which implies an optimization of the bit-error-rate. Testing of the PNN device shows that the excess losses introduced by the PNN device are compensated by the gain in the transmitted signal equalization for a link longer than 100 km. The measured data are reproduced by a model that accounts for the optical link and the PNN device. This allows simulating the network performances for higher data rates, where the device shows improvement with respect to the benchmark both in terms of performance and ease of use..
Photonics Research
- Publication Date: May. 01, 2023
- Vol. 11, Issue 5, 878 (2023)
Surface Optics and Plasmonics
Interaction of plasmonic bound states in the continuum
Bound states in continuum (BICs) are believed to have the ability to achieve high quality factor (Q factor) resonances, which is very important for plasmonics. However, the study of plasmonic BICs is not sufficient. Herein, wshow moreBound states in continuum (BICs) are believed to have the ability to achieve high quality factor (
Photonics Research
- Publication Date: Apr. 21, 2023
- Vol. 11, Issue 5, 724 (2023)
Directional surface plasmon polariton scattering by single low-index dielectric nanoparticles: simulation and experiment
Xuqing Sun, Hongyao Liu, Liwen Jiang, Ruxue Wei... and Chengjun Huang|Show fewer author(s)
Directionally scattered surface plasmon polaritons (SPPs) promote the efficiency of plasmonic devices by limiting the energy within a given spatial domain, which is one of the key issues to plasmonic devices. Benefitting fromshow moreDirectionally scattered surface plasmon polaritons (SPPs) promote the efficiency of plasmonic devices by limiting the energy within a given spatial domain, which is one of the key issues to plasmonic devices. Benefitting from the magnetic response induced in high-index dielectric nanoparticles, unidirectionally scattered SPPs have been achieved via interference between electric and magnetic resonances excited in the particles. Yet, as the magnetic response in low-index dielectric nanoparticles is too weak, the directionally scattered SPPs are hard to detect. In this work, we demonstrate forward scattered SPPs in single low-index polystyrene (PS) nanospheres. We numerically illustrate the excitation mechanism of plasmonic induced electric and magnetic multipole modes, as well as their contributions to forward SPP scattering of single PS nanospheres. We also simulate the SPP scattering field distribution obtaining a forward-to-backward scattering intensity ratio of 50.26:1 with 1 μm PS particle. Then the forward scattered SPPs are experimentally visualized by Fourier transforming the real-space plasmonic imaging to
Photonics Research
- Publication Date: Apr. 28, 2023
- Vol. 11, Issue 5, 765 (2023)
About the Cover
Two-beam phase correlation spectroscopy is a label-free technique to quantify the dynamics of flowing particles, such as red blood cells in vessels of live zebrafish, utilizing the intrinsic refractive index contrast of particles against the fluid background in correlation analysis. See Lan Yu et al., pp. 757-764
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