Open AccessOptimizing up-conversion single-photon detectors for quantum key distribution
Author(s) -
Yang Ni,
Quan Yao,
Xiaozhu Xie,
Yang Liu,
Peizhen Xu,
Wei Fang,
Ming-Yang Zheng,
Jingyun Fan,
Qiang Zhang,
Limin Tong,
Jian-Wei Pan
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.397767
Subject(s) - quantum key distribution , optics , detector , lithium niobate , single mode optical fiber , photon , materials science , optoelectronics , waveguide , optical fiber , physics
High-performance single-photon detectors (SPDs) at 1550-nm band are critical for fiber-based quantum communications. Among many types of SPDs, the up-conversion SPDs based on periodically poled lithium niobate waveguides are of great interest. Combined with a strong pump laser, the telecom single-photons are converted into short wavelength ones and detected by silicon-based SPDs. However, due to the difficulty of precise controlling waveguide profile, the direct coupling between a single-mode fiber and the waveguide is not efficient. Here by utilizing fiber taper with proper diameter, optimal mode-matching is achieved and coupling efficiency up to 93% is measured. With an optimized design, a system detection efficiency of 36% and noise counting rate of 90 cps are realized. The maximum detection efficiency is characterized as 40% with a noise counting rate of 200 cps. Numerical simulation results indicate that our device can significantly improve the performance of QKD and extend the communication distance longer than 200 km.