基于SiPM的高性能光子数可分辨探究

High-Performance Photon Number Resolution Research Based on SiPM

摘要: 硅光电倍增管(SiPM)光子数分辨性能受限于暗计数、光学串扰及高频信号堆积等，无法满足高速光子检测的需求。我们基于被动淬灭SiPM，采用了高通滤波放大与低噪声射频放大结合的方案，增强信号幅度的同时抑制基线漂移，在保障信号完整性的前提下提升多光子雪崩事件的分辨率，实现了雪崩信号的大动态范围线性提取。高通滤波后，雪崩信号的下降时间从50.4 ns减小到3.7 ns，减少了雪崩的堆叠效应，拓宽了器件的响应带宽。在激光重复频率为10 MHz的条件下，实现了最多25个光子的光子数分辨。此外，SiPM输出信号的有效采集对其分辨性能至关重要，我们通过调节示波器垂直采样分辨率，确定了最适合信号采样的区间，为后续SiPM光子数可分辨探测器的集成设计以及动态范围优化提供支持。

Abstract: The photon-number-resolving capability of silicon photomultipliers (SiPM) is constrained by dark counts, optical crosstalk, and high-frequency signal pile-up, limiting their application in high-speed photon detection. In this study, we developed a solution for passive quenching SiPM by integrating high-pass filter amplification with low-noise radiofrequency amplification. This approach enhances signal amplitude while suppressing baseline drift, achieving high-resolution discrimination of multi-photon avalanche events and enabling linear extraction of avalanche signals across a wide dynamic range. After high-pass filter, the avalanche signal fall time was reduced from 50.4 ns to 3.7 ns, effectively mitigating avalanche pile-up effects and expanding the device bandwidth. Under 10 MHz laser repetition rate excitation, the system demonstrated photon-number resolution for up to 25 photons. Furthermore, the effective acquisition of the SiPM output signal is crucial to its resolution performance. We optimized signal acquisition by adjusting the vertical resolution of the oscilloscope to determine the optimal sampling parameters, providing critical guidance for the integrated design and dynamic range optimization of photon-number-resolving SiPM detectors.