Surface defect gap solitons in optical lattices with nonlocal nonlinearity

Abstract

We show that stable surface fundamental defect solitons can exist in different gaps of an optical lattice with focusing nonlocal Kerr nonlinearity. For positive defect, solitons stably exist in the semi-infinite gap. For negative defect, solitons are stable in the semi-infinite gap and the first gap. Increasing the negative defect depth, the existent regions of defect solitons in the semi-infinite gap and in the first gap will be changed. The degree of the nonlocality will affect the profiles of these solitons.