Vortex solitons in moire optical lattices

TL;DR

This paper demonstrates that optical moire lattices can support various vortex solitons in Kerr media, with properties influenced by lattice geometry and transition regimes, including stable embedded solitons.

Contribution

It introduces the existence and stability analysis of vortex solitons in moire optical lattices with different geometries and transition regimes, including the novel finding of stable embedded solitons.

Findings

Vortex solitons exist in moire lattices with different geometries.

Threshold power depends on the twist angle and soliton family.

Stable embedded vortex solitons are found in the incommensurate phase.

Abstract

We show that optical moire lattices enable the existence of vortex solitons of different types in self-focusing Kerr media. We address the properties of such states both in lattices having commensurate and incommensurate geometries (i.e., constructed with Pythagorean and non-Pythagorean twist angles, respectively), in the different regimes that occur below and above the localization-delocalization transition. We find that the threshold power required for the formation of vortex solitons strongly depends on the twist angle and, also, that the families of solitons exhibit intervals where their power is a nearly linear function of the propagation constant and they exhibit strong stability. Also, in the incommensurate phase above the localization-delocalization transition, we found stable embedded vortex solitons whose propagation constants belong to the linear spectral domain of the system.