A fully packaged 4/spl times/4 integrated optical switch matrix

This paper describes a packaged and fiber array coupled 4/spl times/4 optical crosspoint switch designed for optical packet switching. Alignment and fixation techniques of two perpendicular fiber arrays to the integrated InP-based switch chip have been developed. Thermal management is also included in the packaging. The packaged devices demonstrate long-term stability and have been used in switch modules, including the packaged device and electronic interfaces.     

电压切换回路的隐患分析

双母线接线方式下的主变和线路操作箱中都设有电压切换回路。电压切换继电器同时动作将会引起PT二次并列并烧毁PT二次保险,从而使全站保护装置失压的现象;双重故障下,甚至造成全站失压,扩大事故范围的严重后果。针对电压切换回路中存在的这种隐患,本文进行了详细的分析探讨,并提出了一些相应措施,以提高电压切换回路的可靠性以及变电站运行的可靠性。     

Intimate monolithic integration of chip-scale photonic circuits

In this paper, we introduce a robust monolithic integration technique for fabricating photonic integrated circuits comprising optoelectronic devices (e.g., surface-illuminated photodetectors, waveguide quantum-well modulators, etc.) that are made of completely separate epitaxial structures and possibly reside at different locations across the wafer as necessary. Our technique is based on the combination of multiple crystal growth steps, judicious placement of epitaxial etch-stop layers, a carefully designed etch sequence, and self-planarization and passivation steps to compactly integrate optoelectronic devices. This multigrowth integration technique is broadly applicable to most III-V materials and can be exploited to fabricate sophisticated, highly integrated, multifunctional photonic integrated circuits on a single substrate. As a successful demonstration of this technique, we describe integrated photonic switches that consume only a 300 /spl times/300 /spl mu/m footprint and incorporate InGaAs photodetector mesas and InGaAsP/InP quantum-well modulator waveguides separated by 50 /spl mu/m on an InP substrate. These switches perform electrically-reconfigurable optically-controlled wavelength conversion at multi-Gb/s data rates over the entire center telecommunication wavelength band.     

Micromechanical optoelectronic switch and amplifier (MIMOSA)

We report for the first time the monolithic integration of a micromechanical modulator and a p-n photodiode on a silicon substrate yielding a versatile optoelectronic device. Because both devices are monolithically integrated on a silicon substrate, the combination is compact with minimal parasitic elements. We demonstrate that such a device combination fields a transistor-like element with positive and negative small-signal voltage amplification. The maximum small-signal voltage gain achieved is 500 while the modulated current of the device exhibits a maximum ON-OFF ratio of 3:1. In addition, while the theoretical current gain of the device is infinite, a 10-pA noise level limited the measured dc current gain to 10⁶     

220kV断路器压力闭锁回路分析应用

220 kV断路器要求有两组独立的操作回路,这就要求与之配合的断路器SF6压力闭锁、液压操作机构压力闭锁回路也应有两组独立的才行,但由于一些早期断路器只能提供一组相关压力闭锁接点,这就要求怎样将一组接点转换成两组接点供两组操作回路用而又能互相不受影响;对于新期投运的断路器,断路器自身就有两组闭锁回路分别供两组操作回路用,但如何正确接线,才能保证其真正的独立性。对此,文章根据目前的断路器现状进行了分析,提出了相关注意事项,防止了错误接线的产生。     

A silicon MEMS optical switch attenuator and its use in lightwavesubsystems

A single-mode fiber connectorized microelectromechanical systems (MEMS) reflective optical switch attenuator operating in the 1550-nm wavelength region is described. The device consists of an electrostatically actuated gold-coated silicon vane interposed in a fiber gap yielding 0.81-dB minimum insertion loss in the transmit state and high transmission isolation in the reflection state with 2.15-dB minimum return loss. The switch attenuators also work as continuously variable optical attenuators capable of greater than 50-dB dynamic range and can be accurately regulated with a simple feedback control circuit. Switching voltages were in the range of 5-40 V and a switching time of 64 μs was achieved. The MEMS switch can be used in optical subsystems within a wavelength-division-multiplexed (WDM) optical network such as optical power regulators, crossconnects, and add/drop multiplexers. We used a discrete array of 16 switch attenuators to implement a reconfigurable 16-channel 100-GHz spacing WDM drop module of an add/drop multiplexer. Thru-channel extinction was greater than 40 dB and average insertion loss was 21 dB. Both drop-and-transmit of multiple channels (11-18-dB contrast, 14-19-dB insertion loss) and drop-and-detect of single channels (>20-dB adjacent channel rejection, 10-14-dB insertion loss) were demonstrated     

一种矩阵开关MA模块的设计

介绍了一种矩阵开关MA模块,详细阐述了M/MA接口及驱动电路的设计思想,并使用FPGA完成M/MA接口的时序设计和继电器开关的控制逻辑,同时采用HL和LL双层软件架构实现模块的驱动程序.测试结果表明,模块可稳定工作在四种模式下,能够完成开关连续快速动作,并可对单个开关切换次数进行记录,保证了信号实时可靠的切换.     

Compact evanescent optical switch and attenuator withelectromechanical actuation

We report the design and the realization of an out-of-plane bending structure supporting a waveguide that is used as an optical attenuator and an optical switch. Both devices are based on evanescent field interaction induced by spatial confinement either between two waveguides or between one waveguide and an absorbing medium. The attenuator exhibits typical attenuation of 65 dB/cm. Even if the bad quality of the waveguide has prevented the correct operation of the switch, we show that the attenuation figure establishes the feasibility of a compact evanescent optical coupler with mechanical drive featuring a total length below 1 mm     

Applications of PSPICE simulation software to the study ofoptoelectronic integrated circuits and devices

Software models for Si and GaAs pin photodetectors are described, for use in the simulation of optoelectronic integrated circuits (OEICs). These preliminary models, which include the effects of dark current and lumped internal impedance, are completely integrable with PSPICE software, and may be used to study the operating characteristics of independent devices and cascaded components in complex OEICs. Parametric device dependence on applied bias, doping density, and wavelength of incident light are also established. The simulation of more advanced OEICs can be implemented with the subsequent modeling of other passive and active components, including waveguide modulators and light emitting sources. The use of PSPICE simulation software in the study of optoelectronic devices and circuits described should find wide application in upper division core or elective optical electronic courses and laboratories     

Hybrid integration of smart pixels by using polyimide bonding:demonstration of a GaAs p-i-n photodiode/CMOS receiver

The fabrication procedure of smart pixels based on a hybrid integration of compound semiconductor photonic devices with silicon CMOS circuits is described. According to the 0.8-μm design rule, CMOS receiver/transmitter circuits are designed for use in vertical-cavity surface-emitting laser (VCSEL)-based smart pixels, and 16×16 and 2×2 Banyan-switch smart-pixel chips are also designed. By using our polyimide bonding technique, we integrated GaAs pin-photodiodes hybridly on the CMOS circuits. The photodetector (PD)/CMOS hybrid receiver operated error free at up to 800 Mb/s. Successful optical/optical (O/O) operation (a bit rate up to 311 Mbit/s) of the 2×2 Banyan-switch smart-pixel chip implemented with another VCSEL chip is also demonstrated     

Circuits simulation of switch devices furnished with gain cell combined to FeRAM

Abstract

This paper has described a new concept on programmable switch device furnished with gain cell combined to FeRAM. Compared with memories but ferroelectric memories under many aspects, they have even been favorably labeled the ideal memory because of their non-volatility, ease of programming and operation by low voltage. As the programming switch, which is very attractive for logic application, SRAM, anti-fuse, flash type devices are well known. They have been required that satisfy non-volatility and low-voltage programming simultaneously. Some structures with ferroelectric material have been proposed and studied as solution of these problems. However, it seemed hard that these type devices are realized now from a viewpoint of fabrication process and low voltage operation. Therefore, we propose a new switch device furnished with gain cell combined to FeRAM. We have studied and simulated this switch device by SPICE. This basic circuit is composed of two blocks. One is switching block that includes gain cell, and the other is memory block that is FeRAM. Circuits, which we designed, amplify bit line's voltage up to Vdd or ground at sense amplification according to FeRAM data. The bit line voltage determines the logic state for gate electrode of switch transistor. The way to read is destructive read out. However, we can transfer information of bit line voltage during plate line is low-level voltage. The way to write FeRAM is similar to conventional way. It is revealed that the basic circuit with FeRAM connected gain cell could work correctly in simulation. In addition, this kind of device is hopeful of many logic applications.     

Computation of the I/V characteristic of a molecular switch

We report on the study of a molecular torsional switch made up of two distinct aromatic moieties bound by an acetynil group. The mechanism of operation is based on the action of a static electric field perpendicular to the ring–ring bond which modifies the torsional angle and, as a consequence, the inter-ring conjugation. The current is computed with a method based on the molecular Green’s function, in which the electrodes are taken into account in an effective way. The current/voltage profile at several dihedral angles shows that the current is maximum for the planar conformation and decreases by a factor ∼1000 for the orthogonal conformation, suggesting the potential applicability of the proposed switching function in devices at the molecular scale.     

Optical receivers for optoelectronic VLSI

We describe our work on the design and testing of optical receivers for use in optoelectronic VLSI. The local nature of the optoelectronic VLSI system permits novel receiver designs, incorporating multiple optical beams and/or synchronous operation, while the requirement of realizing large numbers of receivers on a single chip severely constrains area and power consumption. We describe four different receiver designs, and their different operating modes. Results include 1-Gb/s high-impedance, two-beam diode-clamped FET-SEED receivers, single and dual-beam transimpedance receivers realized with a hybrid attachment of multiple-quantum well devices to 0.8-μm linewidth CMOS operating to 1 Gb/s, and synchronous sense-amplifier-based optical receivers with low (~1 mW) power consumption. Finally, we introduce a measure of receiver performance that includes area and power consumption     

开关柜中电快速瞬变脉冲群耦合途径的研究及电磁隔离

为了抑制高压开关柜中的电快速瞬变脉冲群在微机保护装置的外壳上感应出骚扰电压和骚扰电流,在电磁场有限元仿真软件ANSOFT中根据开关柜的结构建立开关柜模型,分别仿真研究电快速瞬变脉冲群电压和电快速瞬变脉冲群电流形成的瞬态电磁场对微机保护装置外壳的耦合过程,并采取电磁屏蔽和空间隔离等措施切断其耦合途径.仿真结果表明,通过研究开关柜中电快速瞬变脉冲群的耦合过程而制定的电磁隔离措施可以有效减弱耦合到微机保护装置外壳的电快速瞬变脉冲群.     

Characterization and snubbing of a bidirectional MCT switch in aresonant AC link converter

The MOS-controlled thyristor (MCT) is emerging as a powerful switch that combines the characteristics of existing power devices. This paper presents a study of switching stresses on the MCT under zero voltage resonant switching. Two MCTs and two diodes are connected to form a bidirectional switch which was used in an AC/AC resonant link inverter. Current and voltage spikes are observed and analyzed with variations in the timing of the MCT switching. Different snubber circuit configurations are investigated to minimize the effect of these transients. Some failure modes of the device are also presented     

EMTDC异步电动机模型及起动过程仿真

详细介绍了EMTDC中三相异步电动机模型 ,尤其是机械部分模型 ,给出了机械部分与电气部分的接口以及暂态求解过程。基于EMTDC对正常情况、定子匝间短路及转子断条故障时的起动转速—转矩关系进行了仿真研究 ,得出了仿真曲线 ,分析结果证明利用EMTDC可为内部故障诊断提供一个仿真环境     

Polymeric electrooptic 2×2 switch consisting of bifurcationoptical active waveguides and a Mach-Zehnder interferometer

We interpret the modified bifurcation optically active waveguide switch structure for a polymeric electrooptic (EO) 2×2 switch. PEI-DR1, UFC150, and Resole HM2 were used as the core EO material, the lower clad material, and the upper clad material, respectively. We present the optical and electrical properties on this material system for high-performance devices. We fabricate the electrically and optically packaged polymeric EO 2×2 switch for high-speed optical communications. At an operating voltage of 8.5 V, the crosstalk of the cross-arm is -18.1 dB, and that of the straight arm is -18.5 dB. The measured optical loss is 14 dB at λ=1.3 μm. The 6-dB attenuation in radio-frequency transmission corresponds to about 17 GHz     

A new efficient dcvs circuit synthesis technique used for an improved implementation of a serial/parallel multiplier

This paper describes an efficient technique for the design of fault-secure VLSI circuits based on differential cascode voltage switch (DCVS) logic. We propose a new synthesis method for constructing DCVS circuits with a near-optimal transistor count based on binary decision diagrams (BDDs). the time and memory resources required are very low, making the technique practical even for PC-based synthesis tools. This method is the basis for a CAD tool that allows automatic synthesis of fault-secure circuits based on the DCVS technology. We finally present an improved design and implementation of a 2's complement serial/parallel multiplier as an application of the proposed technique and algorithm.     

Photonics for switching and routing

The ongoing growth of data traffic from existing and new applications poses a challenge to the packet-switched network infrastructure. High-capacity transport can be achieved in such networks by using dense wavelength-division-multiplexed systems, and reconfigurable optical add-drop multiplexers allow the optical layer to provision wavelength-based circuits between routing nodes. However, construction of the high-capacity packet routers provides significant scaling issues due to complexity, interconnect, and thermal limits. In this paper we will not seek to cover all aspects of optical packet switching and routing but outline some of the challenges facing the construction of such future routers and describe the role photonics can have in overcoming some of these issues. We will discuss how photonics' primary role will be to provide interconnection between racks of electronic routing elements and describe how fast wavelength switching can provide a high-capacity distributed switch fabric that will allow these packet routers to scale to higher capacities. The fast wavelength switching can be seen as the packet analog of wavelength-based circuit switching of today's transparent optical networks.