Cascaded Stokes and anti-Stokes laser based on an optical resonator with a self-assembled organic monolayer

TL;DR

This paper demonstrates enhanced cascaded and anti-Stokes Raman scattering in a silica resonator modified with an organic monolayer, achieving low-power operation and significant efficiency improvements.

Contribution

The study introduces a surface modification technique with an organic monolayer to significantly boost Raman gain in whispering-gallery mode resonators.

Findings

Up to four orders of CSRS observed at sub-mW input power.

SARS efficiency improved by three orders of magnitude.

Enhanced Raman processes enabled by organic monolayer surface modification.

Abstract

Due to their high circulating intensities, ultra-high quality factor dielectric whispering-gallery mode resonators have enabled the development of low threshold Raman microlasers. Subsequently, other Raman-related phenomena, such as cascaded stimulated Raman scattering (CSRS) and stimulated anti-Stokes Raman scattering (SARS), were observed. While low threshold frequency conversion and generation have clear applications, CSRS and SARS have been limited by the low Raman gain. In this work, the surface of a silica resonator is modified with an organic monolayer, increasing the Raman gain. Up to four orders of CSRS is observed with sub-mW input power, and the SARS efficiency is improved by three orders of magnitude compared to previous studies with hybrid resonators.