# Octave-wide phase-matched four-wave mixing in dispersion engineered crystalline microresonators

## TL;DR

This paper demonstrates phase-matched four-wave mixing in crystalline microresonators, generating broad frequency combs with potential for tunable mid-infrared applications, validated by experiments, theory, and simulations.

## Contribution

It introduces a dispersion-engineered crystalline microresonator capable of octave-wide phase-matched four-wave mixing, advancing frequency comb technology.

## Key findings

- Primary sidebands up to 140 THz shift generated
- Localized comb structures near primary sidebands observed
- Experimental results agree with theoretical and numerical models

## Abstract

In this Letter, we report phase-matched four-wave mixing separated by over one-octave in a dispersion engineered crystalline microresonator. Experimental and numerical results presented here confirm that primary sidebands were generated with a frequency shift up to 140 THz, and that secondary sidebands formed a localized comb structure, known as a clustered comb in the vicinity of the primary sidebands. A theoretical analysis of the phase-matching condition validated our experimental observations, and our results good agree well with numerical simulations. These results offer the potential to realize a frequency tunable comb cluster generator operating from 1 um to mid-infrared wavelengths with a single and compact device.