紫外光通信作为新型通信方式，在短距离通信领域具有潜在的应用前景。紫外光通信的探测电路可分为线性模式和盖革模式，盖革模式探测电路在系统带宽和探测灵敏度等方面具有显著优点。本文研究了基于盖革模式雪崩光电二极管（ Avalanche Photodiode，APD）的单光子探测电路，实现对微弱紫外光信号的探测。采用主动淬灭快恢复电路，通过淬灭信号和恢复信号控制 APD阳极电位，从而减小死时间，提高系统的计数上限。实验发现，对于主动淬灭电路而言，当死时间过小时，淬灭时间和恢复时间除了受到淬灭信号和恢复信号控制外，还会受到电路中电容充放电时间的影响。本文从理论和实验两方面研究了电路中电容和电阻对死时间的影响，为进一步缩短死时间提供了理论指导。

Ultraviolet (UV) communication has several potential applications in the field of short-distance communication. The detection circuit of ultraviolet communication can be sorted into linear and Geiger modes. The Geiger mode detection circuit has significant advantages with regard to system bandwidth and detection sensitivity. A single photon detection circuit based on the Geiger mode avalanche photodiode (APD) is studied to detect weak ultraviolet signals. The active quenching circuit is used to control the APD anode potential through the quenching and recovery signals, thereby reducing the dead time and increasing the upper limit of counting. For the active quenching circuit, when the dead time is too small, the quenching and the recovery time are not only controlled by the quenching and recovery signals, but they are also affected by the charging and discharging time of capacitors in the circuit. In this study, the influence of capacitance and resistance on the dead time is investigated both theoretically and experimentally, which provides theoretical guidance for further shortening the dead time.