Large-sensitive-area superconducting nanowire single-photon detector at 850 nm with high detection efficiency

TL;DR

This paper reports the development of large-area superconducting nanowire single-photon detectors at 850 nm with high detection efficiency, low dark counts, and fast response, suitable for satellite-ground quantum communication.

Contribution

The authors fabricated NbN SNSPDs with a 50 um sensitive area using photonic crystal cavities, achieving high efficiency and low dark counts at 850 nm.

Findings

Maximum detection efficiency of 82%

Detection efficiency of 78% at 100 Hz dark count rate

System jitter of 105 ps

Abstract

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.