Superconducting series nanowire single-photon detectors (SNDs) have been used for resolving photon numbers. But it can also exhibit a higher counting rate than a single superconducting nanowire single-photon detector (SNSPD), because the serial architecture allows multiple detectors working in parallel and the inductance of each pixel is reduced. In this paper, we found each pixel of the SND could reset fast although the whole detector took a much longer time for recovering. Therefore, the speed of an SND with a large kinetic inductance of 1.25 μH was characterized and compared to a standard SNSPD with the same total inductance. By measuring the detected photon rate over the input photon rate, we obtained a photon counting rate enhancement by 7.5 times. Meanwhile, the timing jitter of the SND was 63 ps at single photon detection regime. Our results show that the series structure and the readout scheme are quite practical in realizing high speed single-photon detectors besides resolving photon numbers.

中文翻译：

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表征光子数分辨超导纳米线探测器的速度

超导系列纳米线单光子探测器 (SND) 已用于解析光子数。但它也可以表现出比单个超导纳米线单光子探测器 (SNSPD) 更高的计数率，因为串行架构允许多个探测器并行工作，并且每个像素的电感都降低了。在本文中，我们发现 SND 的每个像素都可以快速重置，尽管整个检测器需要更长的时间来恢复。因此，表征了具有 1.25 μH 大动态电感的 SND 的速度，并将其与具有相同总电感的标准 SNSPD 进行了比较。通过测量检测到的光子速率超过输入光子速率，我们获得了 7.5 倍的光子计数率增强。同时，在单光子检测机制下，SND 的时序抖动为 63 ps。