Gap solitons on a ring

TL;DR

This paper introduces a new type of gap solitons supported by azimuthally modulated rings in defocusing media, revealing their properties, stability, and existence domains, including fundamental, even, and twisted states.

Contribution

It presents the first study of azimuthally modulated guiding rings supporting gap solitons with detailed stability analysis and new bound state configurations.

Findings

Fundamental solitons are stable.

Twisted states are always unstable.

Azimuthal modulation significantly alters soliton properties.

Abstract

We introduce a new species of gap solitons (GSs) supported by an azimuthally modulated guiding ring in defocusing cubic media. The periodicity in the azimuthal direction strongly modifies properties and existence domains of GSs. In addition to the fundamental solitons, we report even and twisted bound states. The former type is found to be stable, while the twisted states are always unstable in defocusing media.