基于PD的半导体激光器温度控制系统设计方法

Design method of a PD-based temperature control system for laser diode

半导体激光器常用于抽运与检测激光光源用于原子物理实验与量子科学仪器的研究,而半导体激光器的各特性参数,如阈值电流、峰值波长、输出功率、使用寿命等,均与温度相关,因此对其进行温度控制很重要.根据激光器输出功率与温度之间的关系,提出一种基于光电二极管(PD)的激光器温度控制系统,通过激光管内部集成的PD所获得的激光器光功率,进而得出激光器发光芯片温度,与热敏电阻相结合,以半导体制冷芯片为执行器,构成双闭环控制系统,可实现高精度长期稳定激光器温度控制,稳定度优于±5 m K,能够满足原子物理实验与研究对半导体激光器的要求.

Semiconductor lasers are widely used as pump and probe laser light source in atomic physics and quantum science equipment researches. The characteristics of the laser diodes,such as threshold current,wavelength,output power,lifetime,are temperature dependent,therefore it is vitally important to control the temperature of semiconductor lasers. Based on the relation between laser temperature and the output power,a photodiode（ PD） based laser temperature control system was proposed. The light power of lasers can be acquired by the monitor photodiode in the laser package and then the laser junction temperature can be obtained by the relation between the power and the temperature. A double close loop control system was designed using the photodiode integrated with the temperature sensor and the thermoelectric coolers as the actuator. The test result indicates that the long-term stability of the photodiode-baserd laser diode temperature control system can realize better than ± 5 mK and meet the requirement of semiconductor lasers for the experiment and study of atomic physics.