# A Diamond-Photonics Platform Based on Silicon-Vacancy Centers in a Single Crystal Diamond Membrane and a Fiber-Cavity

## TL;DR

This paper presents a platform integrating silicon-vacancy centers in a diamond membrane with a fiber-based optical resonator, achieving high finesse and enhanced fluorescence, advancing spin-photon interface technology.

## Contribution

It demonstrates that a thin diamond membrane can be integrated into a fiber cavity without degrading its properties, enabling efficient spin-photon interactions with improved absorption characteristics.

## Key findings

- High cavity finesse of up to 3000 maintained with the membrane
- Enhanced fluorescence with an enhancement factor of ~1.9
- Extracted absorption cross section for SiV- centers, higher than previous reports

## Abstract

We realize a potential platform for an efficient spin-photon interface, namely negatively-charged silicon-vacancy centers in a diamond membrane coupled to the mode of a fully-tunable, fiber-based, optical resonator. We demonstrate that introducing the thin ($\sim 200 \, \text{nm}$), single crystal diamond membrane into the mode of the resonator does not change the cavity properties, which is one of the crucial points for an efficient spin-photon interface. In particular, we observe constantly high Finesse values of up to $3000$ and a linear dispersion in the presence of the membrane. We observe cavity-coupled fluorescence froman ensemble of SiV$^{-}$ centers with an enhancement factor of $\sim 1.9$. Furthermore from our investigations we extract the ensemble absorption and extrapolate an absorption cross section of $(2.9 \, \pm \, 2) \, \cdot \, 10^{-12} \, \text{cm}^{2}$ for a single SiV$^{-}$ center, much higher than previously reported.