为准确测量近红外波段单光子探测器量子效率, 搭建了基于自发参量下转换效应的测量系统.系统利用中心波长为518 nm的脉冲激光泵浦周期极化磷酸氧钛钾晶体, 通过自发参量下转换过程产生相关光子对, 分别测量了Si和InGaAs雪崩光电二极管单光子探测器在778 nm和1 550 nm波长点的量子效率, 并对测量不确定度进行了分析.实验表明, 该装置可以测量近红外单光子探测器量子效率参量, 测量不确定度均优于1%.

The measurement facility based on parametric down-conversion technique was established to measure the quantum efficiency of the near-infrared band single-photon detector. The correlated photons were generated via spontaneous parametric down-conversion in a periodically poled potassium titanyl phosphate crystal pumped by a 518 nm picosecond laser. The detection efficiency of Si-avalanche photodiode and InGaAs-avalanche photodiode single-photon detectors were measured via correlated photon pairs at 778 nm and 1 550 nm, respectively, and the measrement uncertainty was analyzed. The experiment results indicated that the facility can measuer near inferad single-photon detectors quantum efficiency with 1% measrement uncertainty.