Towards On-Demand Heralded Single-Photon Sources via Photon Blockade

TL;DR

This paper proposes a cavity-enhanced SPDC scheme utilizing photon blockade to produce high-purity, high-yield single photons on demand, advancing quantum information applications.

Contribution

It introduces a novel method to suppress multi-photon events in SPDC using photon blockade, improving yield without sacrificing purity.

Findings

Single-photon yield exceeds 90%

Photon purity maintained at 99%

Potential for on-demand single-photon generation

Abstract

Spontaneous parametric down-conversion (SPDC) in a laser pumped optical nonlinear medium can produce heralded single photons with a high purity but a very low yield. Improving the yield by increasing the pump power in SPDC inevitably reduces the purity due to excitation of multi-photon events. We propose a scheme to overcome this purity-yield trade-off by suppressing multi-photon events in a cavity-enhanced SPDC via the photon blockade effect. By introducing a strong photon-photon interaction into the intracavity medium and increasing the pump power, we can improve the available single-photon yield to larger than $90\%$, while maintaining a high purity of $99\%$, towards on-demand generation of single photons through the SPDC process. Our quasi-on-demand SPDC sources may boost single-photon-based quantum information technology.