Cavity-enhanced single photon source based on the silicon vacancy center in diamond

TL;DR

This paper demonstrates a highly efficient, cavity-enhanced single photon source using silicon vacancy centers in diamond, achieving increased emission rates and spectral purity at room temperature, with potential for GHz operation.

Contribution

The study introduces a fiber-based microcavity coupling to silicon vacancy centers, significantly enhancing single photon emission properties at room temperature.

Findings

Effective Purcell factor of up to 9.2 observed.

Lifetime changes of up to 31% measured.

Predicted single photon rates beyond 1 GHz with improved materials.

Abstract

Single photon sources are an integral part of various quantum technologies, and solid state quantum emitters at room temperature appear as a promising implementation. We couple the fluorescence of individual silicon vacancy centers in nanodiamonds to a tunable optical microcavity to demonstrate a single photon source with high efficiency, increased emission rate, and improved spectral purity compared to the intrinsic emitter properties. We use a fiber-based microcavity with a mode volume as small as $3.4~\lambda^3$ and a quality factor of $1.9\times 10^4$ and observe an effective Purcell factor of up to 9.2. We furthermore study modifications of the internal rate dynamics and propose a rate model that closely agrees with the measurements. We observe lifetime changes of up to 31%, limited by the finite quantum efficiency of the emitters studied here. With improved materials, our achieved parameters predict single photon rates beyond 1 GHz.