Cavity Optofluidics: Raman Laser Made of a Fiber Coupled nano-Liter Droplet

TL;DR

This paper demonstrates a fiber-coupled, high-Q droplet resonator that produces stimulated Raman laser emission with high efficiency and spectral accuracy, advancing optofluidic laser technology.

Contribution

It introduces a novel ultrahigh-Q droplet resonator integrated with fiber coupling, enabling efficient stimulated Raman emission with high spectral fidelity.

Findings

Achieved Raman laser threshold at 160 μW

Resonator Q factor of 250 million

Emission confined to a 23 μm³ mode volume

Abstract

We fabricate a fiber coupled ultrahigh-Q resonator from a {\mu}droplet per se; and experimentally measure stimulated Raman emission showing itself at a 160{\mu}W threshold. We observe Raman-laser lines that agree with their related calculated molecular-vibrations, as well as with a control-group experiment that uses a Raman-spectrometer. Yet, unlike spectrometers where emission is spontaneous and less directional, our droplet emitter is stimulated, single-mode-fiber coupled, resonantly enhanced with Q of 250 million, confined to a 23 um3 mode volume and has 7 orders of magnitude higher power.