Soliton linear-wave scattering in a Kerr microresonator

TL;DR

This paper investigates how externally injected probe waves interact with dissipative Kerr cavity solitons in microresonators, enabling controlled frequency comb expansion and potential applications in Kerr frequency comb system design.

Contribution

It extends the understanding of soliton-wave scattering to Kerr microresonators, demonstrating controllable comb generation through probe phase detuning both theoretically and experimentally.

Findings

Probe phase detuning controls the idler comb's central frequency.

Interaction enables expansion of the soliton frequency comb.

Experimental validation confirms theoretical predictions.

Abstract

The nonlinear scattering of a linear optical wave from a conservative soliton has been widely studied in optical fibers as a mechanism for nonlinear frequency conversion. Here we extend this analysis to consider the scattering of an externally injected probe wave from a dissipative Kerr cavity soliton circulating in a Kerr microresonator. We demonstrate, both theoretically and experimentally, that this nonlinear interaction can be harnessed for useful expansion of the soliton frequency comb via the formation of a secondary idler comb. We explore the physics of the process, showing that the phase detuning of the injected probe from a cavity resonance plays a key role in setting the central frequency of the idler comb, thus providing a convenient parameter through which to control the spectral envelope of that comb. Our results elucidate the dynamics that govern the interactions between dissipative Kerr cavity solitons and externally injected probe waves, and could prove useful in the design of future Kerr frequency comb systems by enabling the possibility to provide high-power comb lines in a specified spectral region simply through the injection of a suitably chosen probe.