On-Chip Diamond Raman Laser

TL;DR

This paper demonstrates an on-chip diamond Raman laser using high-Q micro-resonators, achieving tunable mid-infrared output with low pump power, marking a significant advancement in integrated photonics.

Contribution

It introduces a fully integrated diamond micro-resonator Raman laser platform with low threshold and tunable output, expanding the application range of diamond-based lasers.

Findings

Achieved >250 μW Stokes output power.

Demonstrated continuous-wave operation with ~85 mW pump threshold.

Enabled mode-hop-free tuning over ~7.5 GHz.

Abstract

Synthetic single-crystal diamond has recently emerged as a promising platform for Raman lasers at exotic wavelengths due to its giant Raman shift, large transparency window and excellent thermal properties yielding a greatly enhanced figure-of-merit compared to conventional materials. To date, diamond Raman lasers have been realized using bulk plates placed inside macroscopic cavities, requiring careful alignment and resulting in high threshold powers (~W-kW). Here we demonstrate an on-chip Raman laser based on fully-integrated, high quality-factor, diamond racetrack micro-resonators embedded in silica. Pumping at telecom wavelengths, we show Stokes output discretely tunable over a ~100nm bandwidth around 2-{\mu}m with output powers >250 {\mu}W, extending the functionality of diamond Raman lasers to an interesting wavelength range at the edge of the mid-infrared spectrum. Continuous-wave operation with only ~85 mW pump threshold power in the feeding waveguide is demonstrated along with continuous, mode-hop-free tuning over ~7.5 GHz in a compact, integrated-optics platform.