Satellite-ground quantum communication requires single-photon detectors of 850-nm wavelength with both high detection efficiency and large sensitive area. We developed superconducting nanowire single-photon detectors (SNSPDs) on one-dimensional photonic crystals, which acted as optical cavities to enhance the optical absorption, with a sensitive-area diameter of 50 um. The fabricated multimode fiber coupled NbN SNSPDs exhibited a maximum system detection efficiency (DE) of up to 82% and a DE of 78% at a dark count rate of 100 Hz at 850-nm wavelength as well as a system jitter of 105 ps.
@article{arxiv.1506.07922,
title = {Large-sensitive-area superconducting nanowire single-photon detector at 850 nm with high detection efficiency},
author = {Hao Li and Lu Zhang and Lixing You and Xiaoyan Yang and Weijun Zhang and Xiaoyu Liu and Sijing Chen and Zhen Wang and Xiaoming Xie},
journal= {arXiv preprint arXiv:1506.07922},
year = {2023}
}