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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Lossless Scalable Optical Switch Design in a SiP/InP Hybrid Platform
摘要： Lossless and distortion-free experimental operation of an 8×8 SiP/InP hybrid optical switch is demonstrated. The design employs an 8-channel InP gain block added to a SiP switch to compensate for its high insertion loss.
关键词： photonic integrated circuits,optical switches,indium phosphide,silicon photonics,hybrid integrated circuits,Optical interconnects
更新于2025-09-16 10:30:52
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1.6-kV 1.5-kA GaAs Avalanche Semiconductor Switch Triggered by 4 ??J Laser Diode
摘要： A current of 1.54 kA was obtained under a bias voltage of only 1.6 kV by employing a single photoconductive semiconductor switch (PCSS) excited by a laser diode (LD) with energy of 4 μJ. In this work, an opposed contact structure PCSS was used instead of a lateral structure one. We show that a avalanche multiplication rate of PCSS as high as 258 has been obtained. The effects of the electric field strength and of the capacitance on the current waveform were investigated. Moreover, the damping degree was calculated in combination with the current waveform. The calculation indicates that the current attenuation degree increases upon the increase of the capacitance for a fixed value of the electric field strength, whereas the current attenuation degree decreases upon the increase of electric field strength for a fixed charging capacitance. The results obtained in this work show that, by employing opposed contact structure PCSSs in combination with a relatively low bias voltage and laser pulse energy, high-current and long pulse power devices based on inexpensive and compact sources can be produced.
关键词： Photoconductive semiconductor switches (PCSS),laser diode (LD),nonlinear mode
更新于2025-09-16 10:30:52
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An azimuthally-modified linear phase grating: Generation of varied radial carpet beams over different diffraction orders with controlled intensity sharing among the generated beams
摘要： Diffraction gratings are important optical components and are used in many areas of optics such as in spectroscopy. A diffraction grating is a periodic structure that splits and diffracts the impinging light beam into several beams travelling in different directions. The diffracted beams from a grating are commonly called diffraction orders. The directions of the diffraction orders depend on the grating period and the wavelength of the impinging light beam so that a grating can be used as a dispersive element. In the diffraction of a plane wave from a conventional grating, the intensities of diffracted beams decrease with increasing order of diffraction. Here, we introduce a new type of grating where in the diffraction of a plane wave, the intensity of a given higher order diffracted beam can be higher than the intensity of the lower orders. We construct these gratings by adding an azimuthal periodic dependency to the argument of the transmission function of a linear phase grating that has a sinusoidal profile and we call them azimuthally-modified linear phase gratings (AMLPGs). In this work, in addition to introducing AMLPGs, we present the generation of varied radial carpet beams over different diffraction orders of an AMLPG with controlled intensity sharing among the generated beams. A radial carpet beam is generated in the diffraction of a plane wave from a radial phase grating. We show that for a given value of the phase amplitude over the host linear phase grating, one of the diffraction orders is predominant and by increasing the value of the phase amplitude, the intensity sharing changes in favor of the higher orders. The theory of the work and experimental results are presented. In comparison with the diffraction of a plane wave from radial phase gratings, the use of AMLPGs provides high contrast diffraction patterns and presents varied radial carpet beams over the different diffraction orders of the host linear phase grating. The resulting patterns over different diffraction orders are specified and their differences are determined. The diffraction grating introduced with controlled intensity sharing among different diffraction orders might find wide applications in many areas of optics such as optical switches. We show that AMLPG-based radial carpet beams can be engineered in which they acquire sheet-like spokes. This feature nominates them for potential applications in light sheet microscopy. In addition, a detailed analysis of the multiplication of the diffraction pattern of an AMLPG by the 2D structure of a spatial light modulator is presented. The presented theory is confirmed by respective experiments.
关键词： radial carpet beams,diffraction gratings,optical switches,light sheet microscopy,azimuthally-modified linear phase gratings
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Optical Cavity-Less 40-GHz Picosecond Pulse Generator in the Visible Wavelength Range
摘要： A method combined ensemble empirical mode decomposition, Volterra model and decision acyclic graph support vector machine was proposed to improve adaptability, feature resolution, and identification accuracy when diagnosing mechanical faults in an on-load tap changer of a transformer. In detail, the ensemble empirical mode decomposition algorithm was applied to decompose the multi-channel vibration signals in the switchover process of the on-load tap changer. Then, a Volterra model for the mechanical state of the on-load tap changer was established based on time-frequency characteristics obtained through the use of the ensemble empirical mode decomposition algorithm. Moreover, a matrix of coefficient vectors was also used in the Volterra model. This method will not only reduce the aliasing effect of empirical mode decomposition but also obtain high-resolution characteristics of nonstationary vibration signals. Furthermore, taking the singular values of the Volterra coefficient matrix as the fault characteristic, the data states of the model for diagnosing the on-load tap changer were automatically classified and identified by establishing a rapid, multi-classification decision acyclic graph support vector machine model with a low misjudgment rate. Finally, based on a certain on-load tap changer, the test platform for simulating mechanical faults was built. On this basis, by using the proposed method, the vibration signals generated due to typical mechanical faults, such as loosening of moving contacts, lessening of transition contact, and motor jam were acquired and analyzed, thus validating the effectiveness of the method through case studies. Compared with other methods, the new method could overcome many defects in existing methods and it has higher fault identification accuracy.
关键词： signal processing algorithms,Mechanical variables measurement,power transformers,fault diagnosis,electromechanical devices,time series analysis,support vector machines,switches
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Bi-Junction Carrier Depletion Type Electro-Optic Phase-Shifters
摘要： Silicon photonic integrated circuits (PICs) combine dense optical system integration with industrial scalability by adopting well-established CMOS fabrication processes. An electro-optic phaseshifter (EOP) represents a basic building unit of several PICs applications, including datacom optical switches, PIC-FPGAs, and beam steering. In-situ resistive-heaters in close vicinity of waveguides, or free-carrier injection/depletion in doped junctions, are common methods to build EOPs. Literature reports thermal shifters consuming 24.7 mW to achieve DC large signal π-phaseshift, power consumption of injection PIN implementations and depletion PN modulators of 10 mW and ≈ 0 mW respectively. A thermal EOP naturally avoids carrier-induced optical insertion losses (IL), in contrast to a PIN/PN modulator. Thus, thermal and PIN/PN methods trade-off IL with electrical power rather than minimizing both. An EOP of low optical losses and low electrical power is highly desired in large-signal, and low-speed applications.
关键词： electro-optic phaseshifter,datacom optical switches,PIC-FPGAs,beam steering,CMOS fabrication,Silicon photonic integrated circuits
更新于2025-09-11 14:15:04
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[IEEE 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fukuoka, Japan (2019.7.7-2019.7.11)] 2019 24th OptoElectronics and Communications Conference (OECC) and 2019 International Conference on Photonics in Switching and Computing (PSC) - Fast Dynamic Control of Optical Data Center Networks Based on Nanoseconds WDM Photonics Integrated Switches
摘要： We demonstrate a fast and dynamic control of photonic switches based DCN by a distributed optical-flow control. Results show error-free 10 Gb/s switching with < 2dB penalty, no packet-loss at switch and 260.66ns end-to-end latency.
关键词： Data Center Network and Subsystem,Optoelectronic and all-optical switches
更新于2025-09-11 14:15:04
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Handbook of Graphene || Graphene Plasmonic: Switching Applications
摘要： This chapter focuses on the graphene plasmonic-based optical switching devices operating in the infrared to terahertz spectrum. Graphene plasmonic due to high strong light–matter interaction and nanoscale size has received significant attention in recent years, as they have found an important role in many areas of optical science and engineering by offering schemes to control electromagnetic fields. Another area of science that has been under the spotlight for the last few years relates to graphene plasmonic metasurface, which is formed of graphene layer packed into a structure. This material exhibits exceptional electronic and optical properties, intriguing many research groups across the world including us. However, our interest is specifically in studying the interaction between electromagnetic waves with surface modes of graphene in multilayer configuration (such as Otto configuration) and switching applications that might follow. In this chapter, relying on theoretical models and numerical simulations, we show that by designing and manipulating optical and electrical properties of graphene such as chemical potential, temperature, scattering rate, as well as incident beam characteristics such as beam width, one can have the structures based on graphene as a good platform for not only infrared optical switching devices but also terahertz switching devices.
关键词： Otto configuration,Graphene plasmonic,graphene conductivity,optical switches,terahertz,metasurface
更新于2025-09-11 14:15:04
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A NOVEL RECONFIGURABLE UWB FILTERING-ANTENNA WITH DUAL SHARP BAND NOTCHES USING DOUBLE SPLIT RING RESONATORS
摘要： This study presents a novel technique for designing an ultra-wideband (UWB) filtering-antenna with dual sharp band notches. This design is composed of a modified monopole antenna integrated with resonant structures. The monopole antenna is modified using microstrip transition between the feedline and the patch. In addition, block with a triangle-shaped slot is loaded on each side of the ordinary circular patch to produce wide bandwidth with better return loss and higher frequency skirt selectivity. The resonant structures are constructed using two double split ring resonators (DSRR) loaded above the ground plane of the antenna to produce dual band notches and filter out WiMAX (3.3–3.7 GHz) and HiperLAN2 (5.4–5.7 GHz) frequencies. The band notch position is controlled by varying the length of the DSRR. The reconfigurability feature is achieved by using two PIN diode switches employed in the two DSRR. The measured results show that the proposed filtering-antenna provides wide impedance bandwidth from 2.58 to 15.5 GHz with controllable dual sharp band notches for WiMAX and HiperLAN, peak realized gain of 4.96 dB and omnidirectional radiation pattern.
关键词： double split ring resonators (DSRR),dual sharp band notches,filtering-antenna,PIN diode switches,WiMAX,HiperLAN2,Ultra-wideband (UWB)
更新于2025-09-10 09:29:36
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Nonlinear manipulation of surface plasmons on graphene-TMDC Bragg reflectors
摘要： In this study, we benefit from the nonlinear optical tunability of the graphene-transition metal dichalcogenide (G-TMDC) heterostructure and the strong confinement of the electromagnetic fields of surface plasmon polaritons (SPPs) on graphene in order to propose a highly tunable nonlinear optical Bragg reflector. Recently, two-dimensional (2D) TMDCs are the subject of intense researches because of their nonlinear optical properties at near infrared wavelengths which are very intriguing for various optical applications. We choose two kinds of 2D-TMDCs, MoSe2 and WSe2, with the strongest second order optical nonlinearity at near infrared range to properly design the periodic variation of the propagating SPP waves on the graphene layer. We utilize theoretical method of quantum electrostatic heterostructure to compute the dielectric function of graphene-TMDCs. Different nonlinearities of two TMDCs lead to noticeable tuning of the full width at half maximum (FWHM) and the central Bragg wavelength of the reflector which let design various optical devices. We design an add/drop filter, a nonlinear switch, and an AND/OR optical logic gate based on our proposed Bragg reflector. Our finite difference time domain numerical and transfer matrix analytical results reveal that by increment of the optical intensity up to 6 MW/cm2 which is below the pulse damage threshold of graphene, due to the second order nonlinearity, a 10-nm red-shift in central Bragg wavelength is observed and the 20-nm FWHM at linear regime decreases to 1.5 nm. The SPP intensities of 0.8 MW/cm2 and 1.53 MW/cm2 fulfill the requirements for AND and OR logical operations with 57 and 66.51 dB extinction ratios, respectively.
关键词： Nonlinear optical materials and devices,Surface plasmons,Nonlinear optics,Optical switches,Bragg grating
更新于2025-09-10 09:29:36
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Recent advances in optical technologies for data centers: a review
摘要： Modern data centers increasingly rely on interconnects for delivering critical communications connectivity among numerous servers, memory, and computation resources. Data center interconnects turned to optical communications almost a decade ago, and the recent acceleration in data center requirements is expected to further drive photonic interconnect technologies deeper into the systems architecture. This review paper analyzes optical technologies that will enable next-generation data center optical interconnects. Recent progress addressing the challenges of terabit/s links and networks at the laser, modulator, photodiode, and switch levels is reported and summarized.
关键词： data centers,photonic technologies,terabit/s links,optical interconnects,optical switches
更新于2025-09-10 09:29:36