高精度和高稳定性半导体激光器恒流驱动电源

High-Accuracy and High-Stability Constant Current Power for Semiconductor Lasers

基于输入电流的微小变化可以引起半导体激光器输出波长和功率显著改变的特征,研制了一种高精度、高稳定性半导体激光器恒流驱动电源。该电源利用运算放大器和场效应管组成恒流源电路,消除了供电电源对输出电流特性的影响,使输出电流仅受调谐电压的变化而改变,提高了输出电流的稳定度;采用高精度基准电压源使调谐电压具有极高的输出精度和稳定度,增强了输出电流的精度;电源慢启动电路避免了浪涌及高压静电等对激光器的损坏,限流保护电路使流过激光器的正向电流不超过允许最大电流值,启停控制电路可根据实验需求随时关闭激光器而不影响电路的其他功能,实现了对激光器的可靠保护。测试结果表明,该电源在输出电流0～200 mA范围内连续可调,输出电流精度为0.01 mA,长期稳定度约为0.004%,具有恒流特性好、纹波小、保护电路可靠、抗干扰能力强、成本低、易实现等特点。

The output power and wavelength of semiconductor lasers are affected by the input current whose tiny change may lead to significant changes in the lasers’ wavelength and optical power. In this paper, a high-accuracy and high-stability constant current power is developed. Field effect tube and operational amplifier are used to improve the stability of current, and high stability reference power is used to enhance the accuracy of current. High reliability is achieved by slow-start of power, current limiting protection and start-stop control circuit. The results show that this power supply is able to continuously adjust the output current from 0 mA to 200 mA, with a current accuracy of 0.01 mA and long-term stability of about 0.004%, and the protection circuit is highly reliable.