Kerr Superoscillator Model for Microresonator Frequency Combs

TL;DR

This paper introduces a frequency-domain model for microresonator frequency combs, using collective excitations called superoscillators, bridging the gap between existing time-domain models and spectral analysis.

Contribution

The paper presents a novel frequency-domain superoscillator model for microcombs, providing an intuitive understanding of spectral structures and connecting with time-domain soliton crystal models.

Findings

Spectral structures described by collective superoscillators.

Links microcomb generation to frequency response theory.

Provides a new frequency-domain perspective on microcombs.

Abstract

Microresonator-based optical frequency combs, or "microcombs", have attracted lots of attention in the last few years thanks to their promising applications in telecommunications, spectroscopy and optical clocks. The process of comb generation in microresonators can be modelled in the frequency domain using coupled mode equations, and has also recently been successfully described in the time domain using a nonlinear Schr\"odinger equation known as the Lugiato-Lefever equation. Though time-domain approaches have brought many interesting insights for the understanding of microcombs, an intuitive frequency-domain model has not yet been established. In this work we present a frequency-domain model of microcombs that describes the overall structure of the spectra in terms of a few collective excitations of groups of neighboring comb lines, which we term "superoscillators". This approach ties in nicely with the recently-developed time-domain model based on soliton crystals, and links the microcomb generation process with frequency response theory.