Stable higher-charge discrete vortices in hexagonal optical lattices

TL;DR

This paper demonstrates that double-charge discrete optical vortices can be stable in hexagonal photonic lattices, unlike single-charge vortices which are inherently unstable, highlighting a new stability regime for optical vortices.

Contribution

It reveals the stability of double-charge vortices in hexagonal lattices, contrasting with the instability of single-charge vortices, and shows their weaker instabilities and longer propagation stability.

Findings

Double-charge vortices can be completely stable in hexagonal lattices.

Single-charge vortices exhibit inherent dynamical instabilities.

Double-charge vortices have weaker instabilities and longer breakup distances.

Abstract

We show that double-charge discrete optical vortices may be completely stable in hexagonal photonic lattices where single-charge vortices always exhibit dynamical instabilities. Even when unstable the double-charge vortices typically have a much weaker instability than the single-charge vortices, and thus their breakup occurs at longer propagation distances.