Transverse localization in nonlinear photonic lattices with second-order coupling

TL;DR

This paper numerically studies how long-range second-order coupling affects light localization in nonlinear zigzag photonic lattices, revealing that coupling and nonlinearity interplay influence localization behavior.

Contribution

It introduces a detailed numerical analysis of second-order coupling effects on transverse light localization in nonlinear photonic lattices, highlighting the complex role of nonlinearity and disorder.

Findings

Localization is hindered by next-nearest site coupling.

Weak nonlinearity enhances localization with disorder.

Strong nonlinearity weakens localization as disorder increases.

Abstract

We investigate numerically the effect of long-range interaction on the transverse localization of light. To this end, nonlinear zigzag optical waveguide lattices are applied, which allows precise tuning of the second-order coupling. We find that localization is hindered by coupling between next-nearest lattice sites. Additionally, (focusing) nonlinearity facilitates localization with increasing disorder, as long as the nonlinearity is sufficiently weak. However, for strong nonlinearities, increasing disorder results in weaker localization. The threshold nonlinearity, above which this anomalous result is observed grows with increasing second-order coupling.