Bragg guiding of domain-like nonlinear modes and kink arrays in lower-index core structures

TL;DR

This paper introduces a new class of stable nonlinear optical modes in lower-index core structures, demonstrating their transformation into defect lattice solitons or kink arrays depending on the core width, with stability of higher-order modes in 1D.

Contribution

It presents a novel class of stable nonlinear modes in lower-index media, including their formation, transformation, and stability analysis, expanding understanding of nonlinear optical guiding.

Findings

Stable nonlinear modes exist in lower-index core structures.

Modes transform into defect lattice solitons or kink arrays based on core width.

Higher-order modes with multiple zeros can be stable in 1D settings.

Abstract

We introduce a novel class of stable nonlinear modes trapped in a lower-index film core sandwiched between two optical lattices, or in the cylindrical core of a radial lattice, imprinted in defocusing media. Such family of nonlinear modes transforms into defect lattice solitons when the core width is sufficiently small or into an array of kinks when the width is large enough. We find that higher-order modes with multiple zeros inside the guiding core can be stable in one-dimensional settings.