Observation of two-dimensional superlattice solitons

TL;DR

This paper reports the experimental observation of two-dimensional superlattice solitons in femtosecond laser-fabricated waveguides, highlighting differences in diffraction patterns, soliton shapes, and power thresholds based on site depth.

Contribution

First experimental demonstration of 2D superlattice solitons with analysis of site-dependent diffraction and power thresholds.

Findings

Deep site solitons require lower power than shallow site solitons.

Symmetry of diffraction patterns varies with site type.

Soliton shapes differ based on the waveguide depth.

Abstract

We observe experimentally two-dimensional solitons in superlattices comprising alternating deep and shallow waveguides fabricated via the femtosecond laser direct writing technique. We find that the symmetry of linear diffraction patterns as well as soliton shapes and threshold powers largely differ for excitations centered on deep and shallow sites. Thus, bulk and surface solitons centered on deep waveguides require much lower powers than their counterparts on shallow sites.