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Optimizing up-conversion single-photon detectors for quantum key distribution
DOI:10.1364/OE.397767.png)
Abstract
En 中文
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. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Keywords:
INGAAS/INP AVALANCHE PHOTODIODES
TAPERED OPTICAL-FIBERS
LOW-NOISE
1550 NM
MU-M
EFFICIENT
PERFORMANCE
WAVELENGTHS
DIAMETER
LONG
Journal
IF:
3.3
Papers:
6.1W
Citations:
14.3W

