Improvements in temporal resolution of single-photon detectors enable increased data rates and transmission distances for both classical and quantum optical communication systems, higher spatial resolution in laser ranging, and observation of shorter-lived fluorophores in biomedical imaging. In recent years, superconducting nanowire single-photon detectors (SNSPDs) have emerged as the most efficient time-resolving single-photon-counting detectors available in the near-infrared, but understanding of the fundamental limits of timing resolution in these devices has been limited due to a lack of investigations into the timescales involved in the detection process. We introduce an experimental technique to probe the detection latency in SNSPDs and show that the key to achieving low timing jitter is the use of materials with low latency. By using a specialized niobium nitride SNSPD we demonstrate that the system temporal resolution can be as good as 2.6 ± 0.2 ps for visible wavelengths and 4.3 ± 0.2 ps at 1,550 nm.

单光子探测器的时间分辨率的提高可以提高经典光学通信系统和量子光学通信系统的数据速率和传输距离，提高激光测距的空间分辨率，并在生物医学成像中观察寿命较短的荧光团。近年来，超导纳米线单光子检测器（SNSPD）成为近红外中最有效的时间分辨单光子计数检测器，但是对这些设备中的定时分辨率的基本限制的理解受到限制由于缺乏对检测过程中涉及的时间尺度的调查。我们引入了一种实验技术来探测SNSPD中的检测延迟，并表明实现低时序抖动的关键是使用低延迟的材料。