高速近红外1 550 nm单光子探测器采用半导体制冷和热管风冷混合技术,雪崩二极管工作于盖革模式下,使用交流耦合方式提供门脉冲信号,通过延迟补偿和采样边沿锁存方式消除尖脉冲干扰,采用反馈门控减小后脉冲的影响。采用了ECL(Emitter Couple Logic)与TTL(Transistor-TransistorLogic)混合电子技术提高单光子探测系统的运行频率,其频率可大于10 MHz;另外,通过对雪崩信号的放大来提高信号的动态范围,进一步优化探测器的性能。实验测试与分析表明,探测器在时钟频率10 MHz、温度-62℃、门脉冲宽度8 ns的条件下的最优性能参数为:量子探测效率12.8%,暗计数率3.76×10-6ns-1,噪声等效功率8.68×10-19W/Hz1/2。
A single photon detector operating in the Geiger mode was cooled to a moderate temperature by using Peltier cooling and heat pipe technology,and a gate pulse signal was coupled to the avalanche diode by a capacity.A moderate delay and edge trigger flip flop were used to avoid the positive and negative transient pulses from influencing the detection of true photon avalanche,a dead time modulation feedback control circuit was used to decrease the after-pulsing,and the working frequency of the detector was improved by ECL(Emitter Couple Logic) and TTL(Transistor-Transistor Logic) technologies which was greatly larger than 10 MHz.In addition,the signal dynamic range was improved through amplifying avalanche signal and the detector performance was further optimized.On the condition that the temperature is-62 ℃,the minimum gate pulse width is 8 ns,and the clock frequency is 10 MHz,it is found that at the optimum operation point the quantum efficiency is about 12.8%,the dark count rate is 3.76×10-6 ns-1 and the noise-equivalent power is 8.68×10-19 W/Hz1/2 from the performance test and analysis.