APD单光子探测的电路设计

Circuit Design of Single-Photon Detector Based on APD

在气体分析领域,由于分子密度的减小,拉曼技术很难获得足够强的信号,为提高检测灵敏度,利用雪崩光电二极管设计了单光子探测器,来检测微弱的拉曼光。系统围绕APD设计了3个主要模块:偏置/测试电源、温控模块、信号调理。测试了系统的暗计数率,并用标准气校验了系统的准确度。实验结果表明:标准差最大为0.905,按总量程计算可得重复性相对偏差为0.905%,而非线性误差取最大引用误差0.13%。其多次测量结果的线性度很好,能够用于线性检测。

In the field of gas analysis due to the reduced molecular density,Raman technique is difficult to obtain a suf-ficiently strong signal,a single photon detector is designed based on an avalanche photodiode to improve the detectionsensitivity of the weak Raman light. The system has four main modules around APD：offset/test power supply,tempera-ture control module,signal conditioning,pulse output. The dark count rate of the system is tested,and by using the stan-dard gas the accuracy of the system was calibrated. The results showed that standard deviation is up to 0.905,accord-ing to the total process,reproducibility relative standard deviation can be calculated to 0.905%,while the non-linear er-ror to take as maximum reference error is 0.13%. Its good linearity measurements can be used for linear detection.