分析了单光子雪崩光电二极管(SPAD)探测器雪崩电压的温度特性,得出SPAD的雪崩电压随温度变化约为0.7 V/°C, 需要设计恒温控制电路保证SPAD的正常工作。从最优温度控制策略的角度,选用MAX1978温度控制芯片 进行电路设计实现SPAD的温度恒定。简要介绍了恒温控制系统的工作原理及各个组成部分。通过恒温 控制电路实验验证了电路的可行性,恒温控制电路可以在1 min内使SPAD的工作环境温度恒定 在0.06°C内,温度控制速度和精度均能满足SPAD温度恒定的要求,确保单光子探测器SPAD正常 工作,使单光子探测器SPAD具有更好的探测性能。

The temperature characteristics of avalanche voltage of single photon detector SPAD were analyzed. It’s concluded that the avalanche voltage of SPAD variation with temperature is about 0.7 V/°C. The constant temperature control circuit was designed to ensure the normal operation of SPAD. From the perspective of the optimal temperature control strategy, MAX1978 temperature control chip design circuit was chosen to realize the SPAD temperature constant. The working principle and main component of constant temperature control system were introduced. Through the experiment of constant temperature control circuit to verify the feasibility of the circuit, constant temperature control circuit can make the SPAD working environment temperature constant at 0.06°C in 1 minute, the speed and accuracy of temperature control can meet the requirement of SPAD temperature constant, and ensure the normal work of the single photon detector SPAD, so that the single photon detector SPAD has better performance.