Visible light emission from a silica microbottle resonator by second and third harmonic generation

TL;DR

This paper reports the first observation of nonlinear harmonic generation, sum frequency generation, and stimulated Raman scattering in a silica microbottle resonator, demonstrating visible light emission via second and third harmonic generation.

Contribution

It introduces the first experimental demonstration of  and  nonlinearities, including harmonic and sum frequency generation, in a silica microbottle resonator.

Findings

Visible light emission from third harmonic generation observed

Sum frequency generation enabled by three- and four-wave mixing

Second harmonic generation enabled by surface effects in silica

Abstract

We report the first observation of nonlinear harmonic generation and sum frequency generation (SFG) coupled with stimulated Raman scattering (SRS) via the second-order (\chi^{(2)}) and the third-order (\chi^{(3)}) nonlinearities in a silica microbottle resonator. The visible light emission due to third harmonic generation (THG) was observed in both the output of a tapered fiber and the optical microscope images, which can be used to identify the axial mode profiles. SFG enabled by three- and four-wave mixing processes between the pump light and the light generated via SRS was also observed. Second Harmonic generation (SHG) and the SFG are enabled by \chi^{(2)} induced in silica by surface effects and multipole excitations.