利用单光子计数技术对微弱光进行探测具有与其他模拟法相比的多个优势, 如有好的抗漂移性、高的信噪比、较宽的线性区等。线性性能是探测器的基本性能之一, 利用叠加法和距离平方反比法测量单光子计数探测系统的线性范围, 当非线性因子为0.05时, 利用叠加法实验测得系统线性响应计数率为3.9×105Counts/s, 利用距离平方反比法实验测得系统线性响应计数率为5×105Counts/s。结果表明, 两种方法测得响应线性度一致性较好。分析了电子学系统的漏计误差对探测器系统线性范围的影响。实验表明, 通过缩短电子学系统中甄别器的死区时间(td)可以提高系统的线性范围。

Using single photon counting technology for weak light detection has many advantages compared with other simulation method,such as good anti-drift,high SNR,wide linear range,etc.Linear performance is one of the basic performance of the detector.By using the superposition method,when the nonlinearity is 5%,the single photon counting detection system achieves a count rate of 3.9×105Counts/s,while the system achieves a count rate of 5×105Counts/s by using the inverse distance square method.The results show that this two methods achieve high consistency in the measurement of the system’s linearity.The influence of the omission counting error of the electronics system on the linearity is analyzed. The test result shows that the linearity of the single photon counting system can be improved by shortening the dead time(td) of the discriminator which is one part of the electronics system.