量子阱半导体激光器P—I特性曲线扭折的研究

小功率窄条形半导体激光器注入电流超过阈值后，其P－I特性曲线可能偏离理想的线性区，出现扭折现象，从而会严重影响激光器与光纤的耦合。本文分析讨论了出现扭折现象与器件结构的关系。通过优化激光器纵向结构设计，采用较窄的有源区，在MOCVD结构生长中用碳作P型掺杂，制造出来的未镀膜激光器在100mA注入电流下输出光功率50mW未出现P－I特性的扭折。     

谈谈光孤子通信

１８４４年，苏格兰海军工程师约翰·斯科特·亚瑟对船在河道中运动而形成水的波峰进行观察，发现当船突然停止时，原来在船前被推起的水波依然维护原来的形状、幅度和速度向前运动，经过相当长的时间才消失。这就是著名的孤立波现象。孤立波是一种特殊形态的波，它仅有一个波峰，波长为无限，在很长的传输距离内可保持波形不变。人们从孤立波现象得到启发，引出了孤子的概念，而以光纤为传输媒介，将信息调制到孤子上进行通信的系统则称作光孤子传输系统。 一、光孤子传输原理 光脉冲在光纤中传播，当光强密度足够大时会引起光脉冲变窄，脉…     

Fabrication of Alq3／PBD OMQW Structures and Its Photoluminescence Characteristics

Organic multiple quantum well(OMQW)structures consisting of alternating layers of tris(8-quinolinolato)aluminum(Ⅲ）（Alq3)an 2-(4-biphenylyl)-5-(4-ter-butylphenyl)-(1,3,3-oxadiazole)(PBD)have been fabricated by organic molecular beam deposition(OMBD).The individual layer thickness in the multilayer samples was varied from 6 nm tp 20nm.The multiple quantum well structures were determined by low angle X-ray diffraction,optical absorption and photoluminescence(PL).The PL spectra narrow and the emission energy has been observed to shift to higher energy compared with that in the monolayer structure,suggesting a quantum size effect.     

NONDESTRUCTIVE BAND—GAP PROFILE DETERMINATION OF HgCdTe LPE CROWN LAYERS

ＩｎｔｒｏｄｕｃｔｉｏｎＭｏｓｔｏｆｍｏｄｅｒｎＨｇ1-ｘＣｄｘＴｅｔｅｒｎａｒｙｃｏｍｐｏｕｎｄＩＲｐｈｏｔｏｄｅｔｅｃｔｏｒｓａｒｅｍａｎｕｆａｃｔｕｒｅｄｆｒｏｍＬＰＥｆｉｌｍｓｇｒｏｗｎｏｎＣｄＴｅａｎｄＣｄＺｎＴｅｓｕｂｓｔｒａｔｅｓ[1～ 4 ] .Ｃｏｍｐｏ ｓｉｔｉｏｎａｌｄｅｐｔｈｎｏｎｕｎｉｆｏｒｍｉｔｙｓｅｅｍｓｔｏｂｅａｎｉｎｈｅｒｅｎｔｆｅａｔｕｒｅｏｆｔｈｅｓｅｆｉｌｍｓ[5,6 ] .Ｉｔｃａｕｓｅｓｔｈｅｖａｒｉａｔｉｏｎｓｏｆｂａｎｄ ｇａｐｗｉｔｈｔｈｅｄｅｐｔｈ ,ｔｈｕｓａｆｆ…     

保偏双光纤准直器的研究与设计

从理论分析了光在自聚焦透镜中的传播性质，进而提出了保偏双光纤准直器的设计和研制，实验结果表明。该保偏双光纤准直器具有良好的插损，回损等性能，并且能成功的运用于偏振光合束器中。     

Atomic Magnetic Lattices and Their Applications

We propose a novel scheme to construct one-,two- or three-dimensional (1D,2D or 3D) atomic magnetic lattices by using various arrays of microscopic magnetic traps,which are composed of some arrays of current-carrying wires.The magnetic field distributions from 1D,2D and 3D arrays of the current-carrying wires are calculated,and some interesting and periodic magnetic microstructures are found.Our study shows that these magnetic lattices may be used to prepare 1D,2D or 3D photonic crystals and so on.     

The Inorganic—free Organic Conductor α′—（ET）2C6H4（SO3）2：Its Synthesis,Structure,and Conductivity

A new ET based cation radical salt,α′-(ET)2C6H4(SO3)2(ET=bis(ethylenedithio) tetrathiafulvalene) has been synthesized by oxidative electro-crystallization and the crystal structure determined to be in monoclinic system, P2/n space group. Its resistivity-temperature curve shows a semi-conductive behavior with a discontinuation at about 150K.