Shen Lijiong, Lee Jianwei, Hartanto Antony Winata, Tan Pengkian, Kurtsiefer Christian
Opt Express. 2021 Feb 1;29(3):3415-3424. doi: 10.1364/OE.409532.
The temporal response of single-photon detectors is usually obtained by measuring their impulse response to short-pulsed laser sources. In this work, we present an alternative approach using time-correlated photon pairs generated in spontaneous parametric down-conversion (SPDC). By measuring the cross-correlation between the detection times recorded with an unknown and a reference photodetector, the temporal response function of the unknown detector can be extracted. Changing the critical phase-matching conditions of the SPDC process provides a wavelength-tunable source of photon pairs. We demonstrate a continuous wavelength-tunability from 526 nm to 661 nm for one photon of the pair, and 1050 nm to 1760 nm for the other photon. The source allows, in principle, to access an even wider wavelength range by simply changing the pump laser of the SPDC-based source. As an initial demonstration, we characterize single-photon avalance detectors sensitive to the two distinct wavelength bands, one based on Silicon, the other based on Indium Gallium Arsenide.
单光子探测器的时间响应通常是通过测量其对短脉冲激光源的脉冲响应来获得的。在这项工作中，我们提出了一种替代方法，使用在自发参量下转换（SPDC）中产生的时间相关光子对。通过测量用未知探测器和参考探测器记录的探测时间之间的互相关，可以提取未知探测器的时间响应函数。改变SPDC过程的临界相位匹配条件可提供波长可调的光子对源。我们展示了该对中一个光子从526nm到661nm以及另一个光子从1050nm到1760nm的连续波长可调性。原则上，通过简单地改变基于SPDC的源的泵浦激光，该源可以访问甚至更宽的波长范围。作为初步演示，我们表征了对两个不同波长带敏感的单光子雪崩探测器，一个基于硅，另一个基于铟镓砷。
