Superconducting nanowire single-photon detectors at a wavelength of 940 nm
W. J. Zhang, Hao Li, Lixing You, Y. H. He, Lingsun Zhang, Xiaoyu Liu, Xuezhi Yang, Junjie Wu, Qi Guo, Shijian Chen, Z. Wang, Xiaohui Xie · AIP Advances · 2015
We develop single-photon detectors comprising single-mode fiber-coupled superconducting nanowires, with high system detection efficiencies at a wavelength of 940 nm. The detector comprises a 6.5-nm-thick, 110-nm-wide NbN nanowire meander fabricated onto a Si substrate with a distributed Bragg reflector for enhancing the optical absorptance. We demonstrate that, via the design of a low filling factor (1/3) and active area (Φ = 10 μm), the system reaches a detection efficiency of ∼60% with a dark count rate of 10 Hz, a recovery time <12 ns, and a timing jitter of ∼50 ps.