Intraresonance frequency combs in Kerr microresonators

TL;DR

This paper demonstrates intraresonance Kerr frequency combs in microresonators using dual-pumping, revealing new dynamics like phase multistability and enabling simpler measurement techniques.

Contribution

It introduces intraresonance comb formation via dual-pumping, a novel regime in microresonator nonlinear optics, with direct observation of complex Kerr dynamics.

Findings

MHz-scale comb-line spacing observed

Parametrically driven phase multistability demonstrated

Dual-pumping simplifies heterodyne measurement

Abstract

For more than 20 years, optical microresonators have served as the backbone of integrated nonlinear photonics, exploiting Kerr nonlinearity to generate octave-spanning frequency combs, enable quantum effects, and drive optical parametric oscillators. Since the inception of microresonator-based nonlinear optics, related studies have focused primarily on regimes in which photons with distinct resonant modes can interact. Although multiple comb lines can occupy a single resonance during the Kerr comb formation process, their mutual interactions have remained largely unexplored. Here we demonstrate a Kerr comb formation that is confined to a single resonance of a microresonator via dual-pumping. MHz-scale comb-line spacing reveals previously unobserved Kerr-comb dynamics, featuring parametrically driven phase multistability that can be observed directly in the temporal domain. Two laser pumps serve as phase-coupled references for heterodyne read-out, simplifying the measurements.