Cavity solitons in a microring dimer with gain and loss

TL;DR

This paper investigates cavity solitons in a coupled microring resonator system with gain and loss, demonstrating tunable existence regions and stability of multiple soliton families, advancing the development of compact frequency comb sources.

Contribution

It introduces the concept of cavity solitons in a gain-loss microring dimer and shows their tunability and stability, which was not previously demonstrated.

Findings

Twofold splitting of resonance increases with decreasing gain/loss

Both CS families can be stable despite gain-loss imbalance

Enables experimental realization of frequency combs in active microrings

Abstract

We address a pair of vertically coupled microring resonators with gain and loss pumped by a single-frequency field. Coupling between microrings results in a twofold splitting of the single microring resonance that increases when gain and losses decrease and that gives rise to two different cavity soliton (CS) families. We show that the existence regions of CSs are tunable and that both CS families can be stable in the presence of an imbalance between gain and losses in the two microrings. These findings enable experimental realization of frequency combs in configurations with active microrings and contribute towards the realization of compact multisoliton comb sources.