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

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.