Optics Express
Polarization-insensitive high-efficiency superconducting nanowire single-photon detector
xin xu, Yue Fei, Qi Chen, Hao Wang, Liang Ma, Mengfan Zhang, Zhuolin Yang, Yanqiu Guan, Huipeng Xia, Xiaoqing Jia, Lin Kang, Labao Zhang, Peiheng Wu
Abstract
Superconducting nanowire single-photon detectors (SNSPDs) struggle to balance high system detection efficiency (SDE) and low polarization dependence. This work proposes a co-design of the NbN films, α -Si anti-reflection coating (ARC), and SiO 2 /Ta 2 O 5 distributed Bragg reflector (DBR) to reduce the polarization-dependent optical response of the nanowires. Simulations based on rigorous coupled-wave analysis (RCWA) and the finite-element method show absorptance above 99% for both transverse-electric (TE) and transverse-magnetic (TM) polarizations and absorptance above 90% over the wavelength range from 1530 to 1640 nm. Experimentally, the device achieves 97% SDE at 1530 nm (polarization sensitivity, PS = 1.1), PS < 1.3 over 1490–1640 nm, 39.5 ns recovery time, and 63.5 ps timing jitter. Retaining a conventional single-layer meander nanowire geometry, this design unifies high efficiency and polarization insensitivity, advancing SNSPD applications in quantum communications, free-space links, and single-photon imaging.