Enhanced Soliton Stability in Bi-directionally Coupled Laser-Microresonator Systems

TL;DR

This paper demonstrates that bi-directional coupling between a Kerr microresonator and a semiconductor laser enhances the stability of 1-solitons, enabling robust frequency comb generation.

Contribution

It introduces a novel bi-directional coupling scheme that stabilizes 1-solitons through a dynamic self-correcting laser response, improving upon unidirectional configurations.

Findings

Bi-directional coupling stabilizes 1-solitons in Kerr microresonators.

Numerical bifurcation analysis identifies existence ranges of soliton states.

Enhanced stability supports robust, self-started frequency combs.

Abstract

We investigate a bi-directionally coupled system consisting of a Kerr-nonlinear microresonator and a continuous-wave single-mode semiconductor laser. Inside the resonator, a forward-propagating and a backscattered field interact nonlinearly, while a fraction of the backscattered field is fed back into the laser cavity. We show in this paper that the interaction of the laser with the feedback opens up new ways of stabilizing $1$-solitons. Using numerical bifurcation analysis, we systematically identify existence ranges of time-harmonic 1-soliton states in the anomalous dispersion regime. We demonstrate that, in contrast to the uni-directional configuration, the bi-directional coupling introduces a dynamic self-correcting response of the laser frequency that stabilizes $1$-solitons. These enhanced stability properties of $1$-solitons thus enable robust and self-started frequency-comb generation, consistent with the existing experimental observations.