闭环温度控制的APD光电探测器设计

Design of closed-loop temperature controlled APD photoelectric detector

针对微弱光信号探测系统中雪崩光电二极管(APD)在工作中的温漂特性,提出了一种适合APD的闭环温度控制方法。该方法将APD、热敏电阻器和TEC制冷器集成在同一组件中,采用模拟电路深度负反馈技术实现闭环温度控制,并运用经典的控制理论建立数学模型对PID电路进行优化,保证了APD探测电路的增益稳定性。试验表明:该系统中APD光电探测器温度控制精度为±0.1℃,输出电压波动约为±0.5 m V,很好地抑制了外界温度变化对APD增益的影响。

Aiming at temperature drift characteristics of avalanche photodiode（ APD） in weak optical signal detection system,a closed-loop temperature control method for APD is proposed. In this way,APD,thermistor and TEC are integrated in the same component,deep negative feedback techniques of analog circuit is used to realize closed-loop control of temperature and classical control theory is used to establish mathematical model to optimize PID circuit in ordor to ensure gain stability of APD detection circuit. Experiment show that temperature control precision of APD is within ± 0. 1 ℃,and fluctuation of output voltage is about ± 0. 5 m V,which indicates the design restrains influence of temperature variation on APD gain very well.