# Space-compatible cavity-enhanced single-photon generation with hexagonal boron nitride

## TL;DR

This paper demonstrates a space-compatible, cavity-enhanced single-photon source using hexagonal boron nitride, improving photon purity and spectrum for quantum communication and computing applications, including satellite-based networks.

## Contribution

It integrates hBN emitters into a tunable microcavity, achieving Purcell enhancement and spectral narrowing, advancing practical quantum photonic devices.

## Key findings

- Enhanced single-photon purity and brightness
- Spectral narrowing via cavity integration
- Potential for satellite-based quantum networks

## Abstract

Sources of pure and indistinguishable single-photons are critical for near-future optical quantum technologies. Recently, color centers hosted by two-dimensional hexagonal boron nitride (hBN) have emerged as a promising platform for high luminosity room temperature single-photon sources. Despite the brightness of the emitters, the spectrum is rather broad and the single-photon purity is not sufficient for practical quantum information processing. Here, we report integration of such a quantum emitter hosted by hBN into a tunable optical microcavity. A small mode volume of the order of $\lambda^3$ allows us to Purcell enhance the fluorescence, with the observed excited state lifetime shortening. The cavity significantly narrows the spectrum and improves the single-photon purity by suppression of off-resonant noise. We explore practical applications by evaluating the performance of our single-photon source for quantum key distribution and quantum computing. The complete device is compact and implemented on a picoclass satellite platform, enabling future low-cost satellite-based long-distance quantum networks.