Mode coupling and photon antibunching in a bimodal cavity containing a dipole-quantum-emitter

TL;DR

This paper demonstrates that mode coupling in a bimodal cavity with a dipole-quantum-emitter enhances photon antibunching and robustness of single-photon devices, even under weak coupling and high dephasing conditions.

Contribution

It reveals that mode coupling significantly improves photon antibunching and device robustness, a novel insight for single-photon source design.

Findings

Strong photon antibunching occurs even with weak DQE-field coupling.

Mode coupling enhances robustness against frequency and coupling mismatches.

Mismatches can be exploited to improve antibunching in weak coupling regimes.

Abstract

We study the effect of mode-coupling on a single-photon device in which a dipole-quantum-emitter (DQE) is embedded in a bimodal whispering-gallery-mode cavity (WGMC). A scatterer is used to induce mode coupling between counter-clockwise and clockwise propagating light fields, which interact with the DQE. In contrast to models for the interaction between a DQE and a (one-mode or two-mode) cavity field, we find that strong photon antibunching can occur even for a weak DQE-field coupling and large dephasing of the DQE, when mode coupling is introduced. We also find that mode coupling can make the device robust against either the frequency mismatch between cavity modes and the DQE or the coupling strength mismatch between the DQE and each mode in the two-mode cavity. Moreover, we find that these mismatches can be used to generate better antibunching in the weak DQE-field coupling regime. Our study shows that mode coupling in a bimodal cavity is very important for the realization of a good single-photon device.