A modified model of the light amplifying optical switch (LAOS)

A new analytical circuit model of the light amplifying optical switch (LAOS) is proposed. The static I-V curve, the switching voltage, and the input-output characteristics can be calculated from this model. The model is based on deriving an expression for the nonlinear current gain of the heterojunction phototransistor (HPT). The switching mechanism and the I-V characteristics of the LAGS is studied in the context of optical and/or electrical feedback. The nonlinear current gain of the HPT, and the Early effect are the main factors which are responsible for the thyristor-like characteristics of the LAOS. An external feedback resistor is also added to achieve the appropriate switching condition and build up the feedback mechanism. A bistable system using a LAGS is also studied as well as the device hysteresis width     

Integrated optical inverter using light amplifying optical switch (LAOS)

An integrated optical inverter is demonstrated. Experimental results show good static input/output characteristics and an on/off ratio suitable for integrated optical logic. The simplicity of this circuit allows compact integration.<>     

Vertical microcavity optical amplifying switch

Optical amplification by stimulated emission is achieved in a vertical microcavity. A fast response of 20 ps and a gain of 2.5 dB point to an optical switch with a modulation width >10 GHz, capable of handling 2 THz signals. The sample studied is composed of an active medium of 130 period GaAs-Al/sub 0.3/Ga/sub 0.7/As multiquantum wells with 10 nm/10 nm nominal layer thickness sandwiched between a pair of Bragg reflector mirrors.<>     

光分组交换网中的一种新模型

目前常用的网络理论模型如曼哈顿网络、洗牌网等均不能适应光分组网络研究的需要.文章提出了一种新的光网络模型———自相似环流网状网.该模型特别适合于光分组网络的研究.文章还研究了该模型的许多特性.     

皮秒级光控光开关研究现状

介绍了目前常用的几种光控光开关(M-Z型、平面反射型、光克尔型、NOLM型、频移型等)的工作原理、性能和应用;介绍了几类对全光开关研究有十分重要意义的新材料;最后探讨了关于如何能够更好的研究光控光开关的一些思路。     

Reflective digital optical switch (RDOS) for DWDM optical networkapplications

A novel, high-performance, reflective digital optical switch for use in dense wavelength-division-multiplexed (WDM) network applications is presented. Highly reliable Ti-LiNbO₃ devices show high-speed polarization-independent reflection modulation with 30-dB ON-OFF ratios over a wavelength range from 1520 to 1570 nm     

A Markov chain model for an optical shared-memory packet switch

This paper first presents a Markov chain that exactly models an optical shared-memory packet switch. Without loss in model accuracy, this Markov chain state size is greatly reduced to form a reduced Markov chain (RMC). A simplified construction method is given to make the RMC tractable. Throughput and probability of packet loss derived using the RMC are also presented     

A new analytical model for the dual-banyan ATM switch throughputcalculation

Dual-banyan is a buffered banyan asynchronous transfer mode (ATM) switch encompassing multiple input-queueing (bifurcated queueing) as its buffering strategy. This paper describes a new analytical model for a throughput evaluation of the dual-banyan switch under different traffic patterns. the model developed and presented enables the computation of buffer state probability and the switch normalized throughput by iterative calculations. The efficiency of the given model is verified through a comparison with simulation results     

A new MOS Type metal tunnel-oxide silicon switch (MOSMISS)

A new MISS device with MOSFET gating is described. The MISS structure employs the thin tunnel oxide to produce the reverse biased field induced drain junction. The quantum mechanical tunneling allows the passage of current and the device to switch to on or off state.     

A silicon-based moving-mirror optical switch

A multimode 2×2 optical switch made from chemically micro-machined silicon piece parts is described. This switch uses microlenses, aligned to fibers by a silicon base, to expand the optical beam and relax alignment tolerances and a pivoting silicon mirrors as the switching mechanism. The moving mirror switch meets or exceeds all the requirements for FDDI applications. The switch loss is typically 0.7 dB and operates at 5 V and 30 mA. The switch insertion/deinsertion time is less than 10 ms, and the optical interruption time is less than 1 ms. The switch design, which minimizes alignments in fabrication and provides for z-axis assembly and the low cost of the high precision piece parts contribute to making this a low-cost switch to manufacture     

A new electrothermal average model of the diode–transistor switch

In the paper a new electrothermal average model of the diode–transistor switch operating in any dc–dc converter is proposed. With the use of this model the non-isothermal characteristics of dc–dc converters in the steady-state can be obtained. The method of formulation of such a model and its structure are described in detail. The correctness of the elaborated model was verified by comparing the SPICE simulated characteristics of the buck and boost converters operating both in the continuous and discontinuous conducting mode, obtained by the electrothermal dc analysis with the proposed model and by the electrothermal transient analysis with the physical models of the diode and the transistor.     

A high-power gate-controlled switch (GCS) using new lifetime control method

A high-power gate-controlled switch (GCS) with high switching speed was developed using a new method for controlling minority-carrier lifetime where both iron and gold were doped into the device. An improved temperature dependence of the forward voltage drop of the device was obtained because each of the forward voltage drops determined by iron and gold has opposite temperature dependence. The lifetime was controlled reproducibly by two-step diffusion of lifetime killers, that is, iron diffusion at high temperature and gold diffusion at lower temperatures afterwards. The relation between the forward voltage drop and the lifetime was theoretically analyzed and the agreement between the theory and experimental results was fairly good. The GCS of 0.15-cm²active area has the ratings of blocking voltage of 1500 V, available turn-off current of 160 A, forward voltage drop of 3 V at anode current of 100 A, and turn-off gain of 9. The turnoff time and turn-on time of less than 2 µs could be obtained. Thedv/dtanddi/dtare 1000 V/µs and 500 A/µs, respectively. The operation of 50 kHz at 100 A/1000 V could be realized with the inductive load of 50 µH by the GCS. The SIPOS (SemiInsulating POlycrystalline-Silicon) passivation was applied to the GCS in order to obtain the high reliability.     

光开关和光开关阵列技术的发展研究

光开关与光开关阵列是DWDM光网络的关键器件，主要用来实现光层的路由选择、波长选择和光交叉连接等功能。文中全面论述比较了光开关和光开关阵列技术。     

光开关和光开关阵列技术的发展研究

光开关与光开关阵列是DWDM光网络的关键器件,主要用来实现光层的路由选择、波长选择和淆交叉连接等功能,文中全面论述比较了光开关和光开关阵列技术。     

Transfer matrix model for evaluation of optical switch structures

A transfer matrix model is proposed as a means to generate switching networks, consisting of 2*2 elementary optical switches with different specifications and any possible state, in a number of ways, and to evaluate the switching network signal/crosstalk ratio and path loss.<>     

A novel twin-ridge-waveguide optical amplifier switch

A novel twin ridge-waveguide optical amplifier switch is reported. The technique of hydrogen passivation of acceptors has been applied to decrease the current spreading in the region between the ridges. The incorporation of a passive waveguide below the active waveguide leads to the result that using 1.53 μm TE polarized light, through and cross states, each with only 1 dB insertion loss, fiber-to-fiber, can be selected in a device of 360 μm length by varying the currents to each ridge with a total current of 140 mA. A minimum crosstalk of less than -33 dB was achieved when the cross state was selected. This is the first report of a twin ridge-waveguide amplifier switch with such a low-loss, low-polarization sensitivity, and low crosstalk     

A survey of new bipolar amplifying and negative-resistance devices

A basic concept of bipolar amplifying devices as well as of negative-resistance devices is formulated. With the aid of this scheme a systematic survey is given for already reported and for possible new amplifying and negative-resistance devices, starting from five basic effects: the pn junction, the metal-(tunnel oxide)-semiconductor diode, the Schottky barrier, the bulk-barrier and the avalanche multiplication. Selecting two of these mechanisms and combining them into a feedback loop, a wide variety of negative-resistance devices can be constructed. Structures with more than two amplifying mechanisms are also briefly considered.     

非线性光学新晶体——二溴三丙烯基硫脲合镉(ATCB)

本文首次报道了一种非线性光学新材料——二溴三丙烯基硫脲合镉(化学式:Cd(C_4H_8N_2S)_3Br_2,简称ATCB)晶体。介绍了采用降温法自水溶液中生长的过程。已生长出的单晶尺寸为20×20×20mm。研究了ATCB单晶的性质。     

一种新型光交换技术:光码标签突发包交换

一种新型光交换技术-光码标签突发包交换技术。该技术是光突发包交换与光码标签交换的结合体，具有两者的共同优点，是一种性能优良的光交换技术。本文首先介绍了该技术的原理，然后给出了网络节点功能结构的设计，最后讨论了该技术的性能。     

A new analytical model for the CQ switch throughput calculation under the bursty traffic

In this paper we propose a new analytical iterative method for the throughput calculation of the Crosspoint Queued (CQ) switch with a random scheduling algorithm under the bursty traffic model. This method is verified by comparing it with the simulation results, which shows a very good match. To the authors’ knowledge, this is the first analytical method for the throughput calculation of such a switch for the bursty traffic model.