Observation of two-dimensional defect surface solitons

TL;DR

This paper reports the experimental observation of two-dimensional defect surface solitons in a hexagonal waveguide array, highlighting how defect properties influence soliton excitation thresholds and the existence of linear surface modes.

Contribution

It provides the first experimental evidence of defect surface solitons in a 2D waveguide array and analyzes how defect refractive index affects their excitation and linear modes.

Findings

Threshold power varies with defect refractive index.

Negative defects support linear surface modes.

Positive defects enable defect surface solitons.

Abstract

We report on the experimental observation of two-dimensional solitons located in a defect channel at the surface of a hexagonal waveguide array. The threshold power for the excitation of defect surface solitons existing due to total internal reflection grows with decrease of the refractive index in negative defects and vanishes for sufficiently strong positive defects. Negative defects can also support linear surface modes existing due to Bragg-type reflections.