Two-dimensional line defect lattice solitons in nonlinear fractional Schrödinger equation

Abstract

The existence, stability, and propagation dynamics of two-dimensional line defect lattice solitons (LDLSs) in a photorefractive crystal with focusing saturable nonlinearity under fractional diffraction effect are numerically investigated. It is shown that, the LDLSs stability domain narrows with increasing Lévy index in the semi-infinite bandgap either in the negative or positive defect lattice. While in the first bandgap, LDLSs are stable for the negative defect lattice and unstable for the positive defect lattice. Additionally, linear stability analysis indicates that the stability and power of LDLSs depend strongly on the Lévy index, defect depth, and propagation constant in different bandgaps. For LDLSs in the semi-infinite bandgap, the stability can be improved by decreasing either the Lévy index or the negative defect depth.