Modulational instability of nonlinear polarization mode coupling in microresonators

TL;DR

This paper explores how nonlinear polarization effects in microresonators lead to new modulational instabilities and frequency comb states, expanding understanding of nonlinear dynamics in integrated photonics.

Contribution

It introduces a coupled Lugiato-Lefever model to analyze polarization-induced instabilities and reveals novel incoherent frequency comb states resulting from nonlinear mode interactions.

Findings

Identification of new modulational instabilities due to polarization effects

Discovery of incoherently coupled frequency comb states

Differences between scalar and polarization-induced instabilities

Abstract

We investigate frequency comb generation in the presence of polarization effects induced by nonlinear mode coupling in microresonator devices. A set of coupled temporal Lugiato-Lefever equations are derived to model the propagation dynamics, and an in-depth study is made of the modulational instability of their multistable homogeneous steady-state solutions. It is shown that new kinds of instabilities can occur for co-propagating fields that interact through nonlinear cross-phase modulation. These instabilities display properties that differ from their scalar counterpart, and are shown to result in the generation of new types of incoherently coupled frequency comb states.