# Optical switching of resonance fluorescence from a single germanium vacancy color center in diamond

## TL;DR

This paper demonstrates a method to control and amplify resonance fluorescence from single germanium vacancy centers in diamond using a weak non-resonant laser, enabling stable quantum emitter operation for scalable quantum networks.

## Contribution

It introduces a controlled gating technique to recover and enhance resonance fluorescence in GeV centers, improving their stability for quantum network applications.

## Key findings

- Resonance fluorescence can be stabilized using weak non-resonant laser gating.
- Gated excitation enhances fluorescence stability of GeV centers.
- Method paves the way for reliable quantum emitters in diamond.

## Abstract

Scalable quantum photonic networks require coherent excitation of quantum emitters. However, many solid-state systems can undergo a transition to a dark shelving state that inhibits the fluorescence. Here we demonstrate that a controlled gating using a weak non-resonant laser, the resonant excitation can be recovered and amplified for single germanium vacancies (GeVs). Employing the gated resonance excitation, we achieve optically stable resonance fluorescence of GeV centers. Our results are pivotal for the deployment of diamond color centers as reliable building blocks for scalable solid state quantum networks.