Power-dependent shaping of vortex solitons in optical lattices with spatially modulated nonlinear refractive index

TL;DR

This paper investigates how the interplay of linear and nonlinear refractive index modulations in optical lattices influences the shape, stability, and power limits of vortex solitons, revealing new stability conditions and shape transformations.

Contribution

It introduces the concept of power-dependent shape transformations of vortex solitons in modulated optical lattices with out-of-phase linear and nonlinear effects, highlighting stability constraints.

Findings

Shape transformations depend on modulation phase relationship.

Nonlinear index modulation limits maximum power of off-site solitons.

Stability is achieved only below a certain nonlinearity modulation depth.

Abstract

We address vortex solitons supported by optical lattices featuring modulation of both the linear and nonlinear refractive indices. We find that when the modulation is out-of-phase the competition between both effects results in remarkable shape transformations of the solitons which profoundly affect their properties and stability. Nonlinear refractive index modulation is found to impose restrictions on the maximal power of off-site solitons, which are shown to be stable only below a maximum nonlinearity modulation depth.