高速大电流脉冲式LIV测试系统的设计与实现

发布时间：2018-01-10 22:11

本文关键词：高速大电流脉冲式LIV测试系统的设计与实现　出处：《武汉理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：为满足激光二极管市场低成本和高可靠性的需求,快速准确的测试激光二极管参数成为其生产和使用过程中的重要环节。激光二极管特性参数通常是采用LIV(光-电流-电压)测试系统获取。传统的LIV测试系统采用直流恒流源测试,测试过程中LD会不断发热,影响其特性曲线的真实性。为解决这个问题,目前国外广泛采用脉冲式LIV测试系统,避免了LD在测试过程中的温升,测试数据可靠性更高。同时考虑到大功率半导体激光器和光纤激光器的测试需求,系统要求能输出大电流。高速大电流脉冲式LIV测试系统设计复杂,国内的相关产品大量依靠进口,为了降低生产成本,本文提出一种新的解决方案。针对目前国内脉冲式LIV测试系统输出电流小精度低、脉冲宽度大的问题,本文将脉冲信号作为宽带模拟信号处理。采用模拟交流恒流源的思路搭建宽带脉冲恒流源,用改进的I-V转换电路实现高速脉冲光功率测量。本文重点研究内容如下:(1)高速大电流脉冲恒流源需要实现脉冲宽度、脉冲幅度的可调,如何保证边沿陡峭和大输出电流是设计关键。系统采用脉冲信号产生、幅度控制、功率驱动的方式实现参数的单独控制。采用宽带压控增益放大器实现幅度的连续可调。利用硬件反馈与软件反馈相结合的恒流控制方式补偿增益放大器的非线性,实现快速高精度电流幅度控制。采用分立器件搭建的AB类MOS推挽电路克服宽带集成功放输出功率小的问题,实现高速信号的功率放大,同时在其前级添加高增益运放校正幅频响应曲线。(2)高灵敏度电流转换电路需要较高的带宽和电流增益。系统采用改进的跨阻放大器实现I-V变换,T型电阻网络作为反馈电阻,提高电流增益和信号带宽。(3)源与测量间的同步可以大幅度减小数据采样压力。系统采用脉冲上升沿延时同步触发的方式,利用RC延时和数字组合逻辑实现复杂的ADC触发时序。在理论分析的基础上,设计实现了各电路子模块,并对关键电路进行仿真分析。设计完成后绘制了PCB板,对系统进行了调试和修改,系统实现了预期目标。本脉冲式LIV测试系统具有脉冲宽度窄(0.5us)、电流大(5A)的突出特点。
[Abstract]:In order to meet the demand of low cost and high reliability in laser diode market. Rapid and accurate measurement of laser diode parameters has become an important part of its production and application. The characteristic parameters of laser diode are usually used in Liv (opto-current-voltage). The traditional LIV test system adopts DC constant current source test. In order to solve this problem, pulse LIV testing system is widely used in foreign countries to avoid the temperature rise in the process of LD testing. The reliability of the test data is higher. Considering the testing requirements of high power semiconductor laser and fiber laser, the system needs to output large current. The design of high speed and high current pulse LIV test system is complex. In order to reduce the production cost, a new solution is put forward to solve the problems of low output current accuracy and large pulse width of pulse LIV test system in China. In this paper, the pulse signal is used as the broadband analog signal, and the idea of analog AC constant current source is adopted to construct the broadband pulse constant current source. The improved I-V conversion circuit is used to realize the measurement of high speed pulsed optical power. The main contents of this paper are as follows: 1) the pulse width and pulse amplitude of the high speed and large current pulse constant-current source need to be adjusted. How to ensure the edge steepness and large output current is the key of the design. The system adopts pulse signal generation and amplitude control. Single parameter control is realized by power drive. The amplitude of gain amplifier is continuously adjustable by wideband voltage-controlled gain amplifier. The nonlinearity of gain amplifier is compensated by constant current control method which combines hardware feedback with software feedback. . Fast and high precision current amplitude control is realized. AB class MOS push-pull circuit with discrete devices is used to overcome the problem of low output power of wideband integrated power amplifier and to realize high speed signal power amplification. At the same time, high gain operational amplifier correction amplitude-frequency response curve. 2) the high sensitivity current conversion circuit needs high bandwidth and current gain. The system uses an improved transresistance amplifier to realize I-V transform. As the feedback resistor, T resistor network can greatly reduce the data sampling pressure by increasing the synchronization between the current gain and the signal bandwidth. The system adopts the pulse rise edge delay synchronization trigger mode. The complex ADC trigger timing is realized by using RC delay and digital combination logic. Based on the theoretical analysis, the sub-modules of each circuit are designed and implemented. After the design is finished, the PCB board is drawn, and the system is debugged and modified. The system has achieved the expected goal. The pulse LIV testing system has the outstanding characteristics of narrow pulse width of 0.5 usu, large current of 5A).
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP274;TN31

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