基于光开关的新型激光探测技术研究

文中针对在浓密介质中进行激光探测时,所遇到的介质后向散射致使探测器饱和及疲 劳接收问题,提出了一种基于光开关的新型激光探测技术,可以去除介质中强后向散射,解决探测器饱和及持续疲劳接收问题,从而实现浓密介质激光目标探测的高灵敏度,为达到更远探测距离提供了新的技术手段。     

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。     

MEMS光开关的研究与进展

光开关是光通信网络的重要功能器件,MEMS光开关是最具发展前景的光开关之一。在简介不同种类光开关原理特点的基础上,详细分析了当前主要的MEMS光开关的分类、结构、工艺与性能特点,并给出这一领域的研究与发展状况。     

光开关技术研究

光开关作为光网络的核心元件,一直是光通信领域研究和发展的热点之一,各种各样的实现方案层出不穷。综述了各种光开关技术,探讨各种光开关技术的原理,并分析它在光网络中的应用情况。     

Low threshold and tunable all-optical switch using two-photon absorption in array of nonlinear ring resonators coupled to MZI

In this paper a novel structure based on Mach-Zehnder Interferometer (MZI) and an array of nonlinear ring resonators for all-optical switching including very low threshold, fast and all-optically tunable is presented. In this proposal, an array including N ring resonators is coupled to one arm of MZI to introduce the required nonlinear phase shift to switching. Also, two-photon absorption phenomenon is used and will be proposed as another alternative for manipulation of optical switching properties. The proposed idea needs small chip area (∝1/Ntraditional cases) for implementation. We show that the switching threshold intensity can be decreased with increase of N, decrease of the coupling coefficient and increase of the two-photon absorption coefficient. In this structure with traditional optical fibers with the low nonlinear index of refractions and using an array including 15 ring resonators with 6 mm diameter for each rings only 3 mW for the switching threshold power is required. Also, using erbium-doped fiber for implementation of the rings with the high nonlinear index of refractions and five ring resonators including 0.3 mm diameter, the switching threshold power can be reduced to μW level. If the nonzero two-photon absorption coefficient is considered, the switching threshold will be very smaller than the above-mentioned values. We show that with changing the optical amplifier gain the switching threshold can be tuned. So, the proposal can be used as a functional block for the integrated optical switch with very small and tunable threshold.     

两级交换机中分组有序到达算法研究

为了提高高性能分组交换机的扩展性,张尚正等人提出了一种称为负载平衡交换机(load-balancedswitch)的交换结构,该交换机分为两级交换结构,每一级都采用一种时序固定的连接方式,具有良好的扩展性;同时可以提供100%吞吐量保证。但是,负载平衡交换机的基本结构会出现分组乱序的情况。本文提出了一种在两级负载平衡交换机中保证分组顺序到达的满帧填充算法,该算法具有良好的交换特性(平均时延及吞吐量),同时也是一种分布式算法,各个端口可以独立地进行操作。     

High photosensitivity and low dark current of photoconductive semiconductor switch based on ZnO single nanobelt

Photoconductive semiconductor switch (PCSS) based on ZnO single nanobelt (NB) was fabricated by controlling the concentration of mixed solution and using the probe technique, and applied into a test circuit to control the circuit state. The current-voltage characteristics and voltage spectra were investigated by system source meter and oscillograph, and the results show that the PCSS is of high photosensitivity of ∼10⁴, low dark current of ∼10⁻³ μA, low power consumption of ∼2.45 μW, typical rise time 0.12 s, and decay time 0.15 s. Within the wavelength range of 280-340 nm, the shorter the wavelength is, the higher the voltage response is. The test circuit state conversion between “1” and “0” is obviously corresponding to UV illumination “on” and “off”. The high photosensitivity and low dark current of PCSS can be reasonably explained by using the view point of light absorption and oxygen chemisorption mechanism.     

使用无Q开关脉冲激光器拍摄全息肖像的研究

通常认为拍摄脉冲全息肖像必须使用带有Ｑ开关运转模式的脉冲激光器，否则是不可能拍摄成功的。本文介绍了我们使用无Ｑ开关的脉冲激光器研制出高质量脉冲质量肖像的工作，以及在此情况下应注意的若干问题。     

利用Bit-Slice技术实现ASON大容量交叉

研究了ASON大容量交叉的实现方法.首先说明了ASON大容量交叉的意义,确定了利用电-光-电的交叉实现方案.随后介绍了两种扩充交叉容量的方法:三级CLOS交叉矩阵与Bit-S1ice交叉矩阵.经比较选择Bit-Slice交叉矩阵实现大容量交叉并给出了方案的构成框图及各部分的功能描述.最后提出了实现更大容量交叉的建议与方法.