Semiconductor optical fibres: progress and opportunities

This paper reviews recent progress in the nascent field of semiconductor optical fibres, from the fundamentals through to device demonstration. The incorporation of semiconductor materials into both the step‐index and microstructured fibre geometries provides a route to introducing new optoelectronic functionality into existing glass fibre technologies. Herein, the various fabrication methods that have been developed as of to date are described, and their compatibility with the different semiconductor materials and fibre designs discussed. Results will be presented on the optical transmission properties of several fibre types, with particular attention being paid to the observation of nonlinear propagation in silicon core fibres. Finally, some speculation regarding the future prospects and applications of this new class of fibre will be provided.     

Design of an ultrafast all-optical NOR logic gate based on Mach-Zehnder interferometer using quantum-dot SOA

This paper proposes a design for all-optical NOR logic gate, based on Mach-Zehnder interferometer (MZI) using quantum-dot semiconductor optical amplifier (QD-SOA). In this regard, a theoretical model for an ultrafast all-optical signal processor is developed using QD-SOA to achieve high bit rate operation. We have demonstrated the NOR gate operation in two cases of with and without an optical control pulse. Simulations have been carried out at data bit rates 160 Gb/s, 200 Gb/s, and 250 Gb/s for the case that control pulse is not applied, and also at data bit rates 1 Tb/s and 2 Tb/s in presence of control pulse which leads to improvement of gain recovery time and ultrafast NOR logic operation. In addition, quality factors of the output signals in presence and without the control pulse at different bit rates with different bias currents have been investigated for pseudo-random binary sequence (PRBS) of word length 2⁸–1.     

Polaron effect dependence of thermopower in organic semiconductors

A unified physical model for thermopower was presented in organic semiconductors, based on the Marcus theory and variable-range hopping theory. According to the proposed model, the characteristic of charge carrier thermoelectric transport in organic semiconductors has been investigated. In particular, polaron effects, energetic disorder, and carrier density dependence of the thermopower have been discussed in detailed. The calculation also shows a good agreement with the experimental data in organic semiconductors.     

高增益双层组合GaAs光电导开关设计与实验研究

设计制备了一种由双层半绝缘GaAs:EL2晶体组成的新型超快光电导功率开关.由于触发状态下双层GaAs晶体之间满足动态分压关系,使该开关在强电场偏置下触发时,双层GaAs晶体既能先后发生高增益过程,又能相互抑制对方进入锁定状态,开关输出为近似方波的双峰脉冲.因此,这种开关的工作方式既具有非线性模式特有的所需触发光能小、上升速度快等优点,又具有线性模式特有的重复工作频率高、使用寿命长等优点.偏压6500V时用脉宽8ns、能量3mJ的1064nm激光触发,输出电脉冲的上升沿为13.2ns,下降沿为54.6ns 关键词： 光电半导体开关 高增益 锁定效应     

Electrical properties of metal-oxide semiconductor nano-particle device

We have studied the electrical transport properties of two types of devices utilizing metal-oxide semiconductor nano-particles, Cu₂O and Fe₂O₃. The metal-oxide nano-particles are embedded in a polyimide matrix through chemical reaction between the metal thin film and polyamic acid as a precursor of polyimide. To test the electron tunneling via nano-particles, Au nano-electrodes are fabricated on a SiO₂/Si substrate with a 30 nm gap by electron-beam lithography. A single electron tunneling behavior was apparent in the devices with Cu₂O nano-particle inserted into the nano-gap electrodes. Also, a memory effect was measured in a floating-gated memory device structure with Fe₂O₃ nano-particles embedded in a polyimide matrix.     

泽贝克/佩尔捷效应演示实验

应用半导体温差发电模块制作了半导体温差发电演示装置,该装置可直观演示泽贝克效应及佩尔捷效应,同时还具有测量泽贝克系数等功能.     

UPWIND FINITE VOLUME SCHEMES FOR SEMICONDUCTOR DEVICE

The mathematical model of semiconductor devices is described by the initial boundary value problem of a system of three nonlinear partial differential equations. One equation in elliptic form is for the electrostatic potential; two equations of convection-dominated diffusion type are for the electron and hole concentrations. Finite volume element procedure are put forward for the electrostatic potential, while upwind     

非晶态硒化镉薄膜瞬态光电特性

本文报道用真空热蒸发法淀积的非晶态硒化镉薄膜作光敏介质制备超快光电导探测器。用对撞脉冲锁模Nd:YAG激光器产生的超短光脉冲序列对探测器的响应时间进行检测,结果表明a-CdSe薄膜对皮秒(10^-12秒)级的超短光脉冲作用具有良好的瞬态响应光电特性,探讨a-CdSe薄膜快速弛豫过程的内在机理。     

kHz激光器在武汉卫星观测站的测距实验

高重复频率激光器是kHz卫星激光测距系统的重要组成部分,提高激光发射频率可以有效地获得更多的观测数据,这是当今卫星激光测距领域的发展方向.针对武汉卫星观测站进行的kHz激光测距实验,介绍了kHz激光器的工作过程和原理,分析了影响高重复频率回波探测的因素.实验结果表明:对实验过程中所观测到的中低轨卫星,观测数据量提高了1...     

915 nm宽条形半导体激光器输出特性

为了研究温升对915 nm宽条形应变量子阱半导体激光器输出特性的影响,搭建了基于半导体制冷片(TEC)的双向温控平台对其进行了测试。首先,改变激光器的外表面温度,测量其在不同注入电流时的光功率和波长,并利用CCD相机测量其慢轴发散角。然后,利用计算机仿真软件对激光器的工作状态进行稳态模拟,从而获得了其对应的热分布情况,通过将模拟得到的数据与实验测量的结果进行比较,获得了两者趋于一致的结论:当热功率从2.1 W升高至20.0 W时,慢轴发散角从2.6°增大至5.0°,同时波长发生红移,热透镜焦距减小;激光器波长随温度变化关系的系数约为0.4 nm/℃,器件热阻为1.5 K/W。因此,为了同时获得高的输出功率和稳定的输出波长,有必要将激光器外表面温度精确控制在某一数值,否则波长将会发生漂移;此外,在设计制作高功率半导体激光器时,通过适当增加条宽并采用散热良好的封装结构,可以减小对慢轴发散角的影响。