Active Temporal Multiplexing of Indistinguishable Heralded Single Photons

TL;DR

This paper demonstrates a scalable method for actively multiplexing indistinguishable single photons from multiple temporal modes using fiber optics and electronics, significantly enhancing photon output probability while maintaining high indistinguishability.

Contribution

It introduces a resource-efficient, fiber-based active multiplexing technique that achieves near-deterministic single photon generation with high indistinguishability.

Findings

100% enhancement in single photon output probability

Photon indistinguishability confirmed by 91% Hong-Ou-Mandel visibility

Scalable multiplexing approach using off-the-shelf components

Abstract

It is a fundamental challenge in quantum optics to deterministically generate indistinguishable single photons through non-deterministic nonlinear optical processes, due to the intrinsic coupling of single- and multi-photon generation probabilities in these processes. Actively multiplexing photons generated in many temporal modes can decouple these probabilities, but key issues are to minimize resource requirements to allow scalability, and to ensure indistinguishability of the generated photons. We demonstrate the multiplexing of photons from four temporal modes solely using fiber-integrated optics and off-the-shelf electronic circuits. We show a 100% enhancement to the single photon output probability without introducing additional multi-photon noise. Photon indistinguishability is confirmed by a four-fold Hong-Ou-Mandel quantum interference with a 91% visibility. Our demonstration paves the way for scalable multiplexing of many non-deterministic photon sources to a single near-deterministic source, which will be of benefit to future quantum photonic technologies.