- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Analyzing the effect of higher order nonlinearity on dispersion relation and optical multistability generation in oppositely directed coupler
摘要： We report the influence of higher order nonlinearity on dispersion relation and multistability in oppositely directed coupler with negative index material channel. The study shows that the high intensity electric field shifts the photonic bandgap down in energy. When the positive index material channel of the coupler is influenced by quintic nonlinearity the group velocity of upper branch of dispersion curve (δ–q curve) falls to zero in positive q region and the loop in the lower branch shifts to positive q region. But the minima in upper branch and loop in the lower branch are observed at negative q region when the negative index material channel is influenced by χ(5) nonlinearity. As the curvature of the dispersion relation determines the group velocity dispersion the study report the possibility for dispersion engineering in oppositely directed coupler. Also we observed that the quintic nonlinearity enhances formation of multi stable states.
关键词： Oppositely directed coupler,Multistability,Optical switching,Negative index materials
更新于2025-09-23 15:23:52
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - Wavelength and Space Division Packet Super-Channel Switching System for Future Data Center Optical Networks with a Switching Capacity of 53.3 Tb/s/port
摘要： Data center (DC) traffic is expected to grow at a staggering annual rate over the next years. However, current DC networks, making use of point-to-point optical links and electronical switching systems, may be unable to meet this traffic demand with a reasonable energy consumption. Moreover, DC network traffic, characterized by dense matrices and bursty hot-spots, constitutes an additional challenge for DC networks designers. To address the capacity and energy bottlenecks and meet the traffic demands in future DC networks, this paper proposes a novel high-capacity optical switching system that employs time division multiplexing (TDM), wavelength division multiplexing (WDM), and space division multiplexing (SDM) to realize coherently modulated packet spatial super-channels (pSSCs). This optical switching system is based on three newly developed core-joint switching subsystems: an electro-absorption (EA)-based joint switch with ns switching speed, an acousto optical modulator (AOM)-based joint switch with μs switching speed, and a free-space mirror-based joint switch with ms switching speed. These switching subsystems are used in a network testbed to experimentally demonstrate a 2×2 switching node with 64 wavelength channels, 7-core pSSCs modulated at 32 GBd. The results confirm a record switching capacity of 53.3 Tb/s/port and network protection in case of a multi-core fiber (MFC) failure in less than 10 ms.
关键词： spatial division multiplexing,spatial switching,data center networking,coherent optical switching
更新于2025-09-23 15:22:29
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[IEEE 2018 Iranian Conference on Electrical Engineering (ICEE) - Mashhad (2018.5.8-2018.5.10)] Electrical Engineering (ICEE), Iranian Conference on - The Proposal of New Fano Structure for Optical Switching Applications
摘要： In this paper, an improved Fano device for optical switching purposes is designed. Proposed structure has better transmission characteristics in terms of quality factor, loss and switching contrast than previous structures announced in the literature. Results show that the Q contrast of the cavities leads to the better performance of the Fano switch.
关键词： Optical Communications,Photonic Crystal,All optical switching,Fano shape spectrume,Fano Structure
更新于2025-09-23 15:22:29
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Micromagnetic Modeling of All-Optical Switching
摘要： The control of the magnetization at the microscale by pure optical means is fundamentally interesting and promises faster speeds for data storage devices. Although several experiments have shown that it is possible to locally reverse the magnetization of a ferromagnetic system by means of laser pulses, a completely theoretical description of these all-optical switching (AOS) processes is still lacking. Here, we develop an advanced micromagnetic solver that is applied to the numerical study of the AOS. The solver is based on the Landau–Lifshitz–Bloch equation that governs the dynamics of the magnetization coupled the microscopic three-temperature model, which describes the temporal evolution of the temperatures of the subsystems as caused by laser heating. The helicity-dependent magnetization switching is evaluated by a magnetooptical effective field caused by the inverse Faraday effect when a circularly polarized laser is applied to the sample. All the other usual terms of a full micromagnetic model are included (exchange, anisotropy, and Dzyaloshinskii–Moriya interaction). As a test, the model is used to describe the local magnetization switching of thin-film samples with high perpendicular anisotropy. The results are in a good agreement with available experimental observations.
关键词： Landau–Lifshitz–Bloch (LLB) equation,three temperatures model (3TM),inverse Faraday effect (IFE),micromagnetism,All-optical switching (AOS)
更新于2025-09-23 15:22:29
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Converged Inter/Intradata Center Optical Network with Packet Super-channels and 83.33 Tb/s/port
摘要： We experimentally demonstrate a novel time-slotted, converged inter/intra data center optical network that employs multi-core fibers (MFCs), packet spatial super-channels (pSSCs) and core-joint optical switches. The fundamental switching subsystem is the high-granularity core-joint electro-absorption optical switch, based on an array of electro-absorption 1x4 switching gates with a switching time of approximately 10 ns, and able to jointly switch all the wavelength and spatial channels of the pSSCs simultaneously. Lower granularity core-joint switches may be used in the pSSC switching nodes for other tasks such as network protection or bypass. Previously, we experimentally demonstrated a 2x2 pSSC switching system with a capacity of 53.3 Tb/s/port in a testbed with pSSCs composed of 64 wavelength channels, 7 spatial channels and PDM-QPSK-modulated payloads. In this work, we enhance our testbed experimental setup to demonstrate a record switching capacity of 83.33 Tb/s/port with pSSCs composed of 64 wavelength channels, 8 spatial channels and PDM-8PSK-modulated payloads. We also demonstrate the transparency of the core-joint electro-absorption switch by comparing the new results with the previous PDM-QPSK results in terms of the error-vector magnitude.
关键词： spatial division multiplexing,time division multiplexing,spatial switching,Data center networking,coherent optical switching
更新于2025-09-23 15:21:21
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Broadly Tunable Plasmons in Doped Oxide Nanoparticles for Ultrafast and Broadband Mid-Infrared All-Optical Switching
摘要： Plasmons in conducting nanostructures offer the means to efficiently manipulate light at the nanoscale with subpicosecond speed in an all-optical operation fashion, thus allowing for constructing high performance all-optical signal-processing devices. Here, by exploiting the ultrafast nonlinear optical properties of broadly tunable mid-infrared (MIR) plasmons in solution-processed, degenerately doped oxide nanoparticles, we demonstrate ultrafast all-optical switching in the MIR region, which features with subpicosecond response speed (with recovery time constant of ?400 fs) as well as ultrabroadband response spectral range (covering 3.0-5.0 μm). Furthermore, with the degenerately doped nanoparticles as Q-switch, pulsed fiber lasers covering 2.0-3.5 μm were constructed, of which a watt-level fiber laser at 3.0 μm band show superior overall performance among ever-reported passively Q-switched fiber lasers at the same band. Notably, the degenerately doped nanoparticles show great potential to work in the spectral range over 3.0 μm that is beyond the accessibility of commercially available but expensive semiconducting saturable absorber mirror (SESAM). Our work demonstrates a versatile while cost-effective material solution to ultrafast photonics in the technologically important MIR region.
关键词： tunable plasmons,ultrafast photonics,all-optical switching,doped oxide nanoparticles,mid-infrared
更新于2025-09-23 15:21:21
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Dielectric and electro-optic studies of a ferroelectric liquid crystal dispersed with different sizes of silica nanoparticles
摘要： The impact of the size of silica nanoparticles (SNPs) on the properties of ferroelectric liquid crystals (KCFLC 10R) has been investigated by electro-optical and dielectric techniques. We have found that the doping of silica nanoparticles in the host ferroelectric liquid crystal strongly affects the various properties of doped systems. Doping of silica nanoparticles shows a small decrease in spontaneous polarisation and faster switching time. An improvement in permittivity and conductivity with the temperature at a constant frequency was also noticed after dispersion. This dependence is stronger for large size particles (,40 nm) and weaker for small size particles (~12 nm). The Goldstone mode (GM) shifts towards the higher relaxation frequency. These results would be useful to manufacture better optical and electronic devices for display, switching and beam steering applications.
关键词： relaxation frequency,Ferroelectric liquid crystals,spontaneous polarisation,silica nanoparticles,goldstone mode,electro-optical,switching time
更新于2025-09-23 15:21:01
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Externally controlled Lotka-Volterra dynamics in a linearly polarized polariton fluid
摘要： Spontaneous formation of transverse patterns is ubiquitous in nonlinear dynamical systems of all kinds. An aspect of particular interest is the active control of such patterns. In nonlinear optical systems this can be used for all-optical switching with transistorlike performance, for example, realized with polaritons in a planar quantum-well semiconductor microcavity. Here we focus on a specific configuration which takes advantage of the intricate polarization dependencies in the interacting optically driven polariton system. Besides detailed numerical simulations of the coupled light-field exciton dynamics, in the present paper we focus on the derivation of a simplified population competition model giving detailed insight into the underlying mechanisms from a nonlinear dynamical systems perspective. We show that such a model takes the form of a generalized Lotka-Volterra system for two competing populations explicitly including a source term that enables external control. We present a comprehensive analysis of both the existence and stability of stationary states in the parameter space spanned by spatial anisotropy and external control strength. We also construct phase boundaries in nontrivial regions and characterize emerging bifurcations. The population competition model reproduces all key features of the switching observed in full numerical simulations of the rather complex semiconductor system and at the same time is simple enough for a fully analytical understanding.
关键词： all-optical switching,population competition model,nonlinear optical systems,transverse patterns,Lotka-Volterra system,polaritons,semiconductor microcavity
更新于2025-09-23 15:19:57
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Nonlinear Optics in Dielectric Guided-Mode Resonant Structures and Resonant Metasurfaces
摘要： Nonlinear optics is an important area of photonics research for realizing active optical functionalities such as light emission, frequency conversion, and ultrafast optical switching for applications in optical communication, material processing, precision measurements, spectroscopic sensing and label-free biological imaging. An emerging topic in nonlinear optics research is to realize high efficiency optical functionalities in ultra-small, sub-wavelength length scale structures by leveraging interesting optical resonances in surface relief metasurfaces. Such artificial surfaces can be engineered to support high quality factor resonances for enhanced nonlinear optical interaction by leveraging interesting physical mechanisms. The aim of this review article is to give an overview of the emerging field of nonlinear optics in dielectric based sub-wavelength periodic structures to realize efficient harmonic generators, wavelength mixers, optical switches etc. Dielectric metasurfaces support the realization of high quality-factor resonances with electric field concentrated either inside or in the vicinity of the dielectric media, while at the same time operate at high optical intensities without damage. The periodic dielectric structures considered here are broadly classified into guided-mode resonant structures and resonant metasurfaces. The basic physical mechanisms behind guided-mode resonances, electromagnetically-induced transparency like resonances and bound-states in continuum resonances in periodic photonic structures are discussed. Various nonlinear optical processes studied in such structures with example implementations are also reviewed. Finally, some future directions of interest in terms of realizing large-area metasurfaces, techniques for enhancing the efficiency of the nonlinear processes, heterogenous integration, and extension to non-conventional wavelength ranges in the ultra-violet and infrared region are discussed.
关键词： harmonic generation,guided-mode resonance,four-wave mixing,Mie scattering,optical resonances,nonlinear optics,sub-wavelength gratings,Fano resonances,optical switching
更新于2025-09-23 15:19:57
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[IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Fast switching via frustrated total internal reflection in silicon photonics MEMS-actuated waveguides
摘要： We present a switching concept based on total internal reflection (TIR) and frustrated-TIR (F-TIR) using a MEMS movable waveguide fully compatible with silicon photonics technology. The switching element allows implementing large-scale photonic switches.
关键词： MEMS switch,silicon photonics,Optical Switching,data center networking
更新于2025-09-23 15:19:57