【作者】 赵玲；

【导师】 石家纬；

【作者基本信息】 吉林大学 ， 微电子学与固体电子学， 2004， 硕士

【摘要】 二十世纪六十年代研制的半导体激光器给光电子领域带来了勃勃生机，随着应用领域的扩大，半导体激光器的研究和开发以突飞猛进的速度发展。目前，半导体激光器已广泛的应用于光纤通信、光盘、激光打印、信息存储、医疗、测量、泵浦固体激光器、集成光学等领域，在高新技术领域中起到越来越重要的作用。因此，如何正确、方便的检测半导体激光器的性能、质量并对其可靠性进行评价具有重要的意义。目前半导体激光器通常采用电老化方法进行可靠性评价和筛选。在电老化过程中，好的器件也要经受考验，受到热、电冲击，因此使器件寿命缩短。如果在长时间电老化的过程中遇到系统失控或停电等意外情况，会使器件成批的损坏，损失将是严重的。而且电老化对器件中的潜在缺陷不敏感，具体表现为电老化筛选认为合格的器件在使用过程中也会发生快速失效。因此如何分析影响器件可靠性的因素以及如何把不合格器件（包括具有潜在缺陷的器件）快速、无损、方便地筛选出去是亟待解决的问题。 半导体激光器噪声包括光噪声和电噪声，其中光噪声包括相位噪声和强度噪声，电噪声包括热噪声、散弹噪声、1/f 噪声和 g－r 噪声等。电噪声反映了材料和器件的不完整性，与器件和材料的质量息息相关，在评价器件质量和可靠性方面近年来引起了人们的极大兴趣。在半导体激光器问世不久，人们就开始了对其噪声特性的研]，特别是近年来，随着半导体激光器在各个领域的广泛应用，器件的噪声问题更是引起了人们的普遍关注，对噪声的研究也更加深入和全面。 半导体激光器的低频电噪声测试需要频谱分析仪，但其造价很高，因此本论文提出了能对半导体激光器的噪声进行测试的系统，即基于PC 机的半导体激光器噪声测试虚拟系统，该系统以“虚拟仪器”来取代造价高的频谱分析仪，把仪器软件化，降低了系统的成本。本系统能对噪声进行时域显示、功率谱、功率谱密度、互功率谱、频率响应等测试，并且可以根据信号的特点选择窗函数、数据平均的方法，以期用此系统对半导体激光器进行低频电噪声测试和可靠性评估。 67<WP=75>吉林大学硕士学位论文 本文首先介绍了半导体激光器的噪声特性，特别是对激光器电噪声作了重点的论述，包括电噪声的种类、特点、产生机制、主要应用等。然后介绍了半导体激光器噪声测量的几种常用方法，其中基于 PC 机的数字测量方法是本人在论文期间重点研究内容。该测试系统包括硬件部分和软件部分：硬件部分主要采用了四种电路，它们是前置放大电路、第二级放大电路、滤波电路和采集卡保护电路。该系统主要是测量半导体激光器及其它半导体器件的电噪声，由于这些噪声电压是及其微弱的，通常在几 nV 到几十 nV 之间。因此需要对他们进行放大，以满足数据采集卡的分辨范围，同时放大器的本底噪声要低于这些噪声电压。由于整个系统的本底噪声主要取决于前置放大器，所以本论文采用了英国EG&G 公司生产的 Model 5184 放大器作为前置级放大器，其噪声电压为0.8nV/Hz1/2，固定放大倍数为 1000，基本满足了测量要求。第二级放大电路我们采用了 AD 公司生产的 AD625 仪器放大器，其噪声电压为5nV/Hz1/2，放大倍数 1－104之间可调。针对该系统的需要，本论文设计了一个二阶低通滤波电路和采集卡保护电路，滤波器主要是起抗混叠滤波的作用，而保护电路主要是避免信号过大烧坏采集卡，并且具有一定的放大作用。最后我们采用了阿尔泰公司生产的 USB2007 数据采集卡，它是 USB 总线兼容的数据采集卡，可经由 USB 电缆接入计算机，卡上装有 14Bit 分辨率的 A/D 转换器，为用户提供了 4 路模拟输入通道，A/D转换器输入信号范围±5V，USB2007 采集卡还具有 16 路开关量输出和测频功能；软件部分是整个测试系统的核心，本论文利用“虚拟仪器”技术模仿日本 ADVANTEST 公司生产的 R9211B/C FFT 分析仪的一些功能设计了一台虚拟的频谱分析仪，主要的功能是频谱分析，其中还包括时域波形显示、谱分析、谱密度分析、互谱分析和频率响应分析。目前正在设计将小波分析和 matlab 嵌入到里面。此外软件也包括滤波、加窗、平均等分析仪必备的功能，使得其具有较完善的分析功能，最大限度的降低了系统成本，增强了系统的功能与灵活性。编写软件所使用的是美国 National Instrument 公司开发的 LabVIEW 6.0 语言，它是专为“虚拟仪器”设计的，是一套专为数据采集与仪器控制、数据分析和数据表达而设计的图形化编程软件。它增强了用户在标准的计算机上配以高效 68<WP=76>吉林大学硕士学位论文经济的硬件设备来构建自己的仪器系统的能力。将 LabVIEW 与一般的数据采集以及仪器设备加以组合，设计出虚拟仪器，它包含各种功能函数，从而使编程的工作方便、快捷，编制出的软件界面美观、类似于实际仪器。数据采集卡的驱动程序采用 Visual C++ 6.0 编写，执行速度较快，与 LabVIEW 之间采用 DLL 连接，使数据的采集与处理达到完美的结合。 整个系统的最大特点就是用虚拟仪器（即 P更多还原

【Abstract】 In the 1960s, semiconductor lasers were devised, which brings thethriving future of the Optoelectronics fields. Along with the rapid extensionof applied fields, the semiconductor lasers’ research and development aregoing forward with a very high speed. By now, the laser diodes have beenwidely used in optical fiber communication, CD, laser printing, informationmemory, medical treatment, pumping solid lasers, measuring, integratedoptics and so on. It becomes more important in advanced technology fields.Then, it is very important to measure the performance of LDs exactly andconveniently and to assess the quality and reliability of LDs. At present, theusual method of screen is electric aging in which all devices are aged with aconstant power or a constant current under high temperature and then theearly failed devices are selected. In the aging, the reliable devices are alsosubject to screening, and the lifetime of devices is affected because of thehot and electric hurt. It can cause batches of devices damage when someaccidence happens, for instance, the out of control system or power cut. Onthe other hand, electric aging is not sensitive for latent defects, for example,some devices after electric aging screening are usually found fail rapidly.Thus, the urgent problems are how to analyses the factors which affect thedevice reliability, and how to select the unqualified devices with a fast,nondestructive and conveniently method. Semiconductor laser noise includes light noise and electric noise ,lightnoise includes phase noise and intensity noise, electric noise includesthermal noise 、shot noise、1/f noise、 g-r noise and so on. Electric noiseindicates the defect of material and device, especially, it is very sensitive forvarious reliability-dependent defects. So the electric noise is becoming auseful tool to characterize device quality and reliability. Of late years, it hasgiven rise to the person much interest. So since the semiconductor laserswere developed, the people have studied its noise characteristics. Especially 70<WP=78>吉林大学硕士学位论文of late years, with the semiconductor lasers’ applying extensively in avariety of domains, the questions of the appliance noise have given rise tothe universal concerns of the people, and the studying about the noise ismore earnester and all-rounder. The low-noise measurement of the semiconductor lasers needsfrequency spectrum analyzer. Because it is very expensive, this paper putforward the noise testing system of semiconductor lasers. The system usesvirtual instruments instead of the analyzer, so the cost of the system isreduced. The system can carry out the function of the time domaindisplaying、the spectral analysis、the spectrum density analysis 、crossspectrum analysis and the frequency response analysis, and select themethods of windowing function and the data averaging according to thesignal feature. We expect the system can carry out the low-noisemeasurements and the reliability evaluation of the semiconductor lasers. First, the article introduces the noise characteristic of semiconductorlasers , especially, the electric noise characteristic is mainly summarized,including the varieties、the features、the generation mechanism and theprincipally applying. Secondly, the measuring methods of noise insemiconductor lasers are introduced, in which the ultralow-noise PC-Basedmeasurement system is especially studied. The system includes thehardware part and the software part: the hardware part adopts four circuits,the preamplifier、the second level amplifying circuit、the filtering circuit andthe acquisition card protection circuit. The system is to measure electricalnoise of semiconductor lasers and the other semiconductor devices, and thevoltage of noise is very small, usually between several nV and several tennV. So they need amplifying, in order to achieve the differentiating range ofthe data acquisition card,更多还原