甲烷气体检测中半导体激光器的温度控制

采用可调谐半导体激光吸收光谱技术（TDLAS）的气体浓度检测系统,其半导体激光器（LD）的输出波长在注入电流恒定的情况下受温度影响很大。高精度的LD温度控制能够保证光源输出光谱的中心波长位于待测气体吸收峰。针对LD温度控制技术的特点,采用两级温度控制的思想,一级保证LD外部工作环境温度稳定在一个小的区间内,另一级是以LD组件热电制冷器（TEC）和热敏电阻（RT）结合模拟的比例—积分（PI）环节来实现温度稳定。实验结果表明,设计的温度控制系统具有良好的稳定性,检测精度可达0.01℃,满足实验的要求。

Semiconductor laser temperature control in methane gas detection system

In the gas concentration detection system adopting tunable diode laser absorption spectroscopy（TDLAS）,the output wavelength of the diode laser（LD） is subjected to great impact by temperature under a constant injection current,and high-precision temperature control can ensure that the center wavelength can be located on the gas absorption peak.This paper introduces the use of two-stage temperature control,as required by the characteristics of LD temperature control,one capable of allowing the external environmental temperature of LD to be stabilized at a small interval,and the other capable of achieving temperature stability based on LD components of thermoelectric cooler（TEC） and thermistor（RT） combined with proportion-integral（PI） links.Experimental results show that the temperature control system with a better stability and measurement accuracy up to 0.01 ℃ is up to the test requirements.