An extremely low-noise heralded single-photon source: a breakthrough for quantum technologies

TL;DR

This paper introduces an ultra-low-noise heralded single-photon source with record low residual background photons, achieved through advanced detectors, electronics, and a custom optical switch, significantly advancing quantum technology applications.

Contribution

The authors develop and demonstrate a heralded single-photon source with unprecedented low noise levels, surpassing previous performance benchmarks in quantum photonics.

Findings

Second-order autocorrelation g^{(2)}(0)=0.005(7)

Output Noise Factor of 0.25(1)%

Achieved record low residual background photons

Abstract

Low noise single-photon sources are a critical element for quantum technologies. We present a heralded single-photon source with an extremely low level of residual background photons, by implementing low-jitter detectors and electronics and a fast custom-made pulse generator controlling an optical shutter (a LiNbO3 waveguide optical switch) on the output of the source. This source has a second-order autocorrelation g^{(2)}(0)=0.005(7), and an "Output Noise Factor" (defined as the ratio of the number of noise photons to total photons at the source output channel) of 0.25(1)%. These are the best performance characteristics reported to date.