半导体光电子器件的研究进展

文章综述ＣＬＥＯ’９４及ＩＱＥＣ’９４会议报道的有关光电子器件的发展状况，叙述了大功率ＬＤ、蓝绿光ＬＤ、垂直腔面发射半导体激光器、可调谐ＬＤ及ＯＥＩＣ的最新研究进展。     

射线法研究外腔半导体激光器的调谐范围

利用由射线法导出的广义两段式半导体激光器的输出光谱的表达式，讨论了外腔式半导体激光器（ＥＣＬＤ）的调谐范围，当ＥＣＬＤ调谐到半导体激光二极管的共振波长附近振荡时，可以重到ＥＣＬＤ的最大调谐范围；当激光器调谐到半导体激光二极管的反共振波长附近振荡时，可以获得ＥＣＬＤ的准连续调谐范围；同时，还求得了实现准连续调谐所需的面向外腔的半导体二极管端面的反射率。     

解析式表示外腔半导体激光器的特征参量

用射线法研究了强反馈可调谐外腔式半导体激光器的阈值行为，导出了ＥＣＬＤ被财在不同波长振荡所需的阈值载流子数密度外腔长度及阈值电流的解析表达式，也得到了不同电流ＥＣＬＤ的调谐输出功率及载流子密度的表达式。     

减反射膜与外腔半导体激光器调谐范围

由于镀了减反射膜的半导体激光二极管端面的反射曲线的谱宽有限，而且，增益峰值波长随载流子密度的变化，因而实际上起作用的反射率通常都比能测到的最低反射率高，在腔内可建立的载流子密度的上限比预期的低。在考虑了这些因素后，计算了用这种管子作外腔半导体激光器（ＥＣＬＤ）的增益介质时，ＥＣＬＤ的调谐范围。     

增大ECLD调谐输出曲线双稳环宽度的研究

利用导出的描述外腔半导体激光器（ＥＣＬＤ）双稳特性的阈值载流子密度与振荡频率之间的关系的基本方程求得了跳变点处的载流子密度及的解析表达式,并由此分析了双稳环宽度随ＥＣＬＤ几个关键参量的大小而变化的情况。     

长外腔半导体激光器的调谐连续性

可调谐外腔半导体激光器（ＥＣＬＤ）中的波长选择元件（如光栅，Ｆ－Ｐ标准具等）所选择的波长函数具有一定的频谱宽度，为实现连续调谐该宽度就应足够小，作为首次尝试，在研究了确保ＥＣＬＤ能在激光二极管的以共振长振荡所需的条件后，我们导出该谱宽不能超过的上限值。     

长波长量子阱LD的实用化研究

长波长量子阱ＬＤ的实用化研究李同宁，刘涛，金锦炎，丁国庆，郭建委，胡常炎，吴桐，李明娟，赵俊英，魏泽民（武汉电信器件公司）近十年来，ＭＢＥ、ＭＯＣＶＤ、ＣＢＥ工艺研究在半导体超薄层材料制备行业中非常活跃。国际上长波长多量子阱激光器件多采用ＭＯＣＶＤ工...     

外腔半导体激光器的宏模型

本文给出了外腔半导体激光器大信号宏模型。该模型可以作为光电集成ＥＣＬＤ的计算机辅助设计模型,亦可作为考察光反馈对单模ＬＤ影响的分析模型,模型可以用通用电路分析软件进行分析,分析结果与已报导的理论和实验基本一致。     

光盘系统用半导体激光器

半导体激光器（ＬＤ）作为读取光盘信息的光源,是ＣＤ、ＤＶＤ播放机／ＲＯＭ等光盘系统的重要器件,它的性能往往决定系统的整体性能。文中叙述了光盘用ＬＤ的发展历程及特点,并着重介绍了近红外、红光、紫光、ＬＤ及双工ＬＤ的开发现状。     

多量子阱垂直腔面发射半导体激光器的速率方程分析

依据多量子阱垂直腔面发射半导体激光器（ＶＣＳＥＬＳ）的结构特点,并考虑到腔量子电动力学中自发辐射增强效应,建立了多量子阱ＶＣＳＥＬＳ的速率方程,并给出了其方程的严格解析解,在此基础之上,讨论了ＶＣＳＥＬＳ的稳态特性,并与普通开腔和三维封闭腔中的结果进行了比较,给出了Ｖ     

Lipid droplets: size matters

The lipid droplet (LD), an organelle that exists ubiquitously in various organisms, from bacteria to mammals, has attracted much attention from both medical and cell biology fields. The LD in white adipocytes is often treated as the prototype LD, but is rather a special example, considering that its size, intracellular localization and molecular composition are vastly different from those of non-adipocyte LDs. These differences confer distinct properties on adipocyte and non-adipocyte LDs. In this article, we address the current understanding of LDs by discussing the differences between adipocyte and non-adipocyte LDs.     

Frequency separation locking and synchronization for FDM opticalsources using widely frequency tunable laser diodes

A laser diode (LD) frequency separation locking method (called the reference pulse method) is proposed. This method has advantageous features for frequency division multiplexing (FDM) networks from the viewpoint of frequency separation stability with a strict frequency separation standard, modulation format independence, controllability over a large number of LDs, and frequency synchronization capability. Frequency locking experiments, using four and ten controlled LDs, confirmed that the control system using the method can stabilize frequency spacing for more than 100 LDs. The frequency fluctuation is suppressed to less than 10 MHz. Frequency synchronization, utilizing the reference pulse method, is proposed and demonstrated experimentally for two controlled LD groups, each consisting of three LDs. Frequency discrepancy between two LD groups was only 2.7% of the frequency separation. Required frequency-swept light power and controlled LD power at the detector input for frequency synchronization indicate that more than 50000 LD groups within a 10 km area, each having 100 LDs, can be synchronized simultaneously     

半导体激光器辐照损伤效应实验研究进展

半导体激光器(LD)工作在空间辐射或核辐射环境中时,会受到辐照损伤的影响而导致器件性能退化。文章回顾了不同时期研制的LD(从早期的GaAs LD到量子阱LD和量子点LD)在辐照效应实验方面的研究进展,梳理了国际上开展不同辐射粒子或射线(质子、中子、电子、伽马射线)诱发LD辐射敏感参数退化的实验规律,分析总结了当前LD辐照效应实验方法研究中亟待解决的关键技术问题,为今后深入开展LD的辐照效应实验方法、退化规律、损伤机理及抗辐射加固技术研究提供理论指导和实验技术支持。     

半导体激光器加速寿命测试系统研制

介绍了半导体激光器(LD)加速寿命测试的理论依据,给出了寿命测试的数学模型,并据此研制了新型LD寿命测试系统。该系统在密封抽真空充氮环境下,通过采集恒功工作LD的工作电流随时间变化的信息及所处环境的温度,绘制出LD的老化曲线,即恒功条件下的“I-t曲线”,然后推断LD的使用寿命。     

窄线宽可调谐外腔半导体激光器阵列

介绍一种半导体激光器(LDs)阵列的外腔可调谐系统。腔体是Littrow结构,2个透镜将光栅选取的锁模光信号形成颠倒阵列像反馈回各个LD中。系统容易调整,对中心波长810nm、输出功率20W的单排24管LDs阵列,在光学元件参数均非最佳的情况下,获得线宽0．5nm(230GHz)、可调范围近30nm和输出功率为LDs阵列自由运行时的60％。实验结果表明,阵列中单个LD接收到的锁模信号并不必是自己发出的光,而可以来自阵列中其它LDs;此外,只要阵列中部分LDs获得锁模信号,即可达到全阵列锁模的目的。     

642-nm AlGaInP laser diodes with a triple tensile strain barriercladding layer

For the first time, tensile strain barrier cladding (TSBC) layers were used in AlGaInP laser diodes (LDs). It was found that the TSBC layers can provide a better optical confinement and a better carrier confinement. AlGaInP LDs with and without the TSBC layers were both fabricated. It was found that the 48-mA threshold current of the 5 μm×800 μm gain-guided triple TSBC AlGaInP LD is lower than the 56-mA threshold current of the conventional AlGaInP LD with the same physical size. The characteristic temperature T₀ of the triple TSBC AlGaInP LD (i.e., 117 K) is also higher than the conventional AlGaInP LD (i.e., 99 K)     

GaInAsP/InP lasers with monolithically integrated monitoring photodiodes fabricated by inclined reactive ion etching

Monolithic fabrication of a GaInAsP/InP laser (LD) with a monitoring photodiode (PD) is described. LDs and PDs have etched facets fabricated by inclined reactive ion etching (RIE). The etched LD facing facet PD is perpendicular to the junction plane and the etched PD facet facing LD is inclined by 55 degrees to the plane by the 'windward-leeward effect' of the inclined RIE. Therefore, coupling efficiencies between LDs and PDs are uniform because the multireflection effect of double mirrors does not exist for the LD-PD devices with inclined PD facets. Typical CW threshold current ranges from 20 to 30 mA and light output power from a single facet exceeds 15 mW at 25 degrees C. A PD can detect about 2% of the light beam emitted from an LD facing it.<>     

Fabrication of room temperature continuous-wave operation GaN-based ultraviolet laser diodes

Two kinds of continuous-wave GaN-based ultraviolet laser diodes (LDs) operated at room temperature and with different emission wavelengths are demonstrated.The LDs epitaxial layers are grown on GaN substrate by metalorganic chemical vapor deposition,with a 10×600 μm2 ridge waveguide structure.The electrical and optical characteristics of the ultraviolet LDs are investigated under direct-current injection at room temperature. The stimulated emission peak wavelength of first LD is 392.9 nm,the threshold current density and voltage is 1.5 kA/cm² and 5.0 V,respectively.The output light power is 80 mW under the 4.0 kA/cm² injection current density. The stimulated emission peak wavelength of second LD is 381.9 nm,the threshold current density the voltage is 2.8 kA/cm² and 5.5 V,respectively.The output light power is 14 mW under a 4.0 kA/cm² injection current density.     

半导体激光的多光束耦合、整形及反馈隔离

本文给出一种实现半导体激光的多光束藕合及整形的新方法——界面耦合法,具有结构简单、实现光束耦合数目多及同时实现多光束的整形的特点。本文还结合半导体激光的反馈噪声,分析了常用的偏振隔离系统并给出了实用的设计、加工和装配要求,对实际工作具有指导意义。     

Integrated AlGaAs two-beam LD-PD array fabricated by reactive ion beam etching

Monolitically integrated AlGaAs two-beam laser diode (LD)- photodiode (PD) arrays are described. LDs and PDs have etched facets fabricated by reactive ion beam etching (RIBE). LDs in the array exhibit threshold currents as low as 18 mA and external quantum efficiencies of more than 30% per facet. A PD can detect more than 20% of a light beam emitted from an LD facing it. Crosstalk between the two LD-PD columns (separated by 50 ?m), on the other hand, is suppressed to less than ?20 dB by an AlGaAs optical barrier (5 ?m thick) fabricated between them.