Multispectral Kerr frequency comb initiated by Faraday ripples

TL;DR

This paper introduces a novel method to generate broadband Kerr frequency combs using Faraday ripples in microresonators, expanding the spectral coverage and coherence for advanced optical applications.

Contribution

It presents the first demonstration of Kerr comb initiation via Faraday ripples with azimuthal dispersion modulation, covering multiple telecommunication bands.

Findings

Broadband comb covering O, C, L, and 2 μm bands

High coherence confirmed by heterodyne beat notes

No subcomb offset observed

Abstract

In a uniform microresonator, the generation of a broadband Kerr frequency comb is triggered by Turing patterns. Here, we study a distinctly different route to initiate the Kerr frequency comb by Faraday ripples. Momentum conservation is ensured by azimuthal modulation of the cavity dispersion. With a good agreement with the theoretical analysis, we demonstrate a multispectral Kerr frequency comb covering telecommunication O, C, L, and 2 {\mu}m bands. Comb coherence and absence of a subcomb offset are confirmed by cw heterodyne beat note and amplitude noise spectra measurements. The device can be used for achieving broadband optical frequency synthesizer and high-capacity coherent telecommunication.