A Time-Multiplexed Heralded Single-Photon Source

TL;DR

This paper demonstrates a time-multiplexed heralded single-photon source that significantly increases photon generation efficiency using an optical storage cavity, advancing scalable quantum information processing.

Contribution

It introduces a novel time multiplexing method with a low-loss cavity to enhance heralded single-photon source efficiency without increasing multi-photon noise.

Findings

Achieved a 38.6% single-photon probability in output windows.

Realized a sixfold increase in photon generation compared to non-multiplexed sources.

Maintained low multi-photon contribution despite increased efficiency.

Abstract

Photons have proven to be excellent carriers of quantum information, and play essential roles in numerous quantum information processing (QIP) applications. In particular, heralded single- photon sources via spontaneous parametric-down conversion (SPDC) have been a key technology for demonstrating small-scale QIP, yet their low generation efficiency is a critical limitation for further scaling up optical QIP technology. In order to efficiently overcome the probabilistic nature of SPDC, here we demonstrate time multiplexing for up to 30 time slots of a periodically pumped heralded single-photon source, using a switchable low-loss optical storage cavity. We observe a maximum single-photon probability of 38.6% in periodic output time windows, corresponding to 6 times enhancement over a non-multiplexed source, but with no increase in the contribution of unwanted multi-photon events. Combining this time-multiplexing technique with a heralded source producing pure single-photon states should enable larger scale optical QIP systems than ever realized.