Diamond Brillouin Lasers

TL;DR

This paper demonstrates the first free-space diamond Brillouin laser, achieving high-power, high-coherence output with tunable frequency combs, paving the way for advanced on-chip SBS devices.

Contribution

It introduces a novel free-space diamond Brillouin laser driven by cavity-enhanced Raman generation, overcoming fabrication challenges for integrated SBS devices.

Findings

Tens-of-watts continuous Brillouin laser output at 71 GHz shift

First demonstration of a free-space diamond Brillouin laser

Switchable single Stokes and frequency comb output

Abstract

The coherent interaction between optical and acoustic waves via stimulated Brillouin scattering (SBS) is a fundamental tool for manipulating light at GHz frequencies. Its narrowband and noise-suppressing characteristics have recently enabled microwave-photonic functionality in integrated devices based on chalcogenide glasses, silica and silicon. Diamond possesses much higher acoustic and bandgap frequencies and superior thermal properties, promising increased frequency, bandwidth and power; however, fabrication of low-loss optical and acoustic guidance structures with the resonances matched to the Brillouin shift is currently challenging. Here we use intense cavity-enhanced Raman generation to drive a diamond Brillouin laser without acoustic guidance. Our versatile configuration - the first demonstration of a free-space Brillouin laser - provides tens-of-watts of continuous Brillouin laser output on a 71 GHz Stokes shift with user switching between single Stokes and Brillouin frequency comb output. These results open the door to high-power, high-coherence lasers and Brillouin frequency combs, and are a major step towards on-chip diamond SBS devices.