Indistinguishable Single-Photon Sources with Dissipative Emitter Coupled to Cascaded Cavities

TL;DR

This paper demonstrates that a cascaded two-cavity system can produce highly indistinguishable single photons from room-temperature emitters with relaxed cavity quality requirements, using numerical and analytical models.

Contribution

It introduces a cascaded cavity approach that enhances photon indistinguishability and reduces cavity quality factor needs for room-temperature quantum emitters.

Findings

Cascaded cavities improve photon indistinguishability.

Reduced Q-factor requirements are achievable with current nanocavity technology.

The method works effectively despite strong emitter dephasing.

Abstract

Recently, Grange et al. [Phys. Rev. Lett. 114, 193601 (2015)] showed the possibility of single photon generation with high indistinguishability from a quantum emitter, despite strong pure dephasing, by `funneling' emission into a photonic cavity. Here, we show that cascaded two-cavity system can further improve the photon characteristics and greatly reduce the Q-factor requirement to levels achievable with present-day technology. Our approach leverages recent advances in nanocavities with ultrasmall mode volume and does not require ultrafast excitation of the emitter. These results were obtained by numerical and closed-form analytical models with strong emitter dephasing, representing room-temperature quantum emitters.