相关光子定标的符合测量精度分析

Accuracy Analysis for Coincidence Measurement of Entangled Photons Calibration

采用355nm连续激光泵浦BBO晶体产生参量下转换效应,搭建了相关光子辐射定标实验装置,使用时间数字转换和时间幅度转换两种符合测量方法进行比对测量,定标了不同光子速率下雪崩光电二极管在737nm波段的探测效率,分析了在高光子计数率下死时间和后脉冲等因素对符合测量选取符合门宽和意外符合的影响,比较了不同光子计数速率的测量结果并分析符合测量的修正因素,修正后两种测量结果的相对偏差优于0.25%.采用时间间隔技术测量了不同光子计数率的后脉冲概率,为提高单光子探测器的计数精度和相关光子定标的精度提供依据.

Using a 355 nm CW laser to pump BBO crystal,the measurement device was set up based on spontaneous parametric down conversion.The channel detection efficiency of system at 737 nm was calibrated at different photon rates,with time-to-digital conversion and time-to-amplitude conversion for performing coincidence counts.The influence of death time and afterpulse on the selection of coincidence gate width and accidental coincidence at high photon counting rate is analyzed.The measurement results of different photon counting rates are compared and the correction factors of coincidence measurement are analyzed.The experimental results show that the relative deviations of the two coincidence measurement methods are better than 0.25%.The afterpulse probability at different photon counting rates are measured by time interval analysis,which provides a basis for improving the accuracy of single photon detectors counting and entangled photons photon calibration.