用于气体浓度检测的VCSELs温度控制电路设计

在利用可调谐半导体激光器吸收光谱（TDLAS）技术对气体浓度进行检测时，检测系统对激光器的温度稳定性要求较高。提出了一种基于max1978的VCSEL激光器自动温度控制（ATC）方案，建立了热电制冷器（TEC）的数学模型，对TEC的热惯性进行了测试，以热惯性测试结果为基础对比例积分微分控制（PID）电路参数进行了整定，设计出了具有较高控制性能的温度控制电路。电路采用闭环负反馈自动控制方案，采用PID电路产生控制信号，驱动TEC，实现了对VCSEL激光器工作温度的有效控制。实验测试结果表明，电路的温度控制精度达到+0.03℃,较好地实现了激光器工作温度稳定性的控制。

Design of Temperature Control Circuit for VCSELs Used in Gas Concentration Measurement

In the gas concentration measurement based on tunable diode laser absorption spectroscopy (TDLAS), higher temperature stability of laser is required. To meet this requirement, an automatic temperature control (ATC) proposal is put forward. A mathematical model of the thermoelectric cooler (TEC) is derived. The thermal inertia of TEC is tested and the proportional-integral-derivative (PID) control circuit parameters are determined. Finally, a temperature control circuit with high control performance is designed. The closed negative feedback loop was adopted for the circuit. PID circuit is used to generate control signal and drive the TEC. High accuracy controlling of VCSELs working temperature is realized. The results show that the temperature stability is up to +0.03℃. The temperature control circuit could effectively keep the laser working stable.