【摘要】 提出一种单光子探测器量子效率的绝对自身标定方案 ,利用光参量下转换过程中产生的光子对在时间上的相关性 ,先将参量光束分为两路 ,然后引入相对延时 ,使同时产生的孪生光子先后进入单光子探测器 ,然后将探测器之后的电路分为三路 ,其中一路直接进入计数器得到探测器所探测到的光子的总计数率 ,另两路用电路方法引入和光路相当的相对延时 ,经符合电路后进入计数器 ,得到前后到达探测器的光子对之间的符合计数率 .这样 ,从符合计数率与总光子计数率之比即可在不需要任何其他探测器或者参照标准的情况下获得探测器的量子效率 .文中给出两种方案 ,分别适合连续激光器和高重复频率脉冲激光器更多还原

【Abstract】 An absolute self-calibration method is proposed for determining the quantum efficiency of a single photon detector which does not require any standard reference or a second detector. The method is based on the time correlation of photon pairs generated in parametric downconversion. A beam of frequency downconverted photons is split at a polarizing beamsplitter then recombined at a second beamsplitter, but with a time delay introduced between them so that the two photons of an original pair enter the detector one by one. The photoelectric pulses from the detector are split into three paths; a compensating delay is introduced into two of the paths so that the two signals arrive simultaneously at a coincidence counter; the third path goes directly to a photon counter. From the ratio of the readings of the two counters we can derive the quantum efficiency of the detector. Two methods are given, one for continuous wave lasers and another for high repetition rate pulsed lasers.更多还原