可调谐半导体激光器的精密控制系统设计

Design of precision control systems for tunable semiconductor lasers

为了满足高精密测量领域对半导体激光器高稳定度的要求,设计了一种高稳定度、低噪声的半导体激光器控制系统。该控制系统由电流驱动和温度控制两部分组成,电流控制部分采用负反馈控制保持电流稳定,温度控制部分采用高度集成的MAX1978作为主控芯片,驱动半导体制冷器进行温度补偿。经过实验验证,电流在200m A范围内连续可调,电流控制精度高达1μA,在3k Hz^100k Hz带宽内交流噪声有效值小于300n A,长期温度漂移小于2m℃。结果表明,该系统可用于驱动分布式反馈外腔半导体激光器和分布式布喇格反射半导体激光器。

In order to meet the requirements of high stability of semiconductor laser in high precision measurement field,a semiconductor laser control system with high stability and low noise was proposed. The control system consists of a current driver and temperature controller. A negative feedback was used to maintain the current stability. A highly integrated MAX1978,as main control chip,was used to drive the thermoelectric cooler for temperature compensation. After the experiment verification,current was adjustable in the range of 200 m A,current control accuracy was less than 1μA. The effective value of alternating current noise voltage within 3kHz - 100 kHz bandwidth was less than 300 nA and long-term temperature drift was less than 2m℃. The results show that the system can be used to drive distribibuted feedback external cavity LD lasers and distributed Bragg reflector LD lasers.