Gap solitons supported by two-dimensional parity-time-symmetric optical lattices in saturable media with fourth-order diffraction

Abstract

The existence and the stability of in-phase dipole gap solitons in two-dimensional (2D) parity-time (PT)-symmetric optical lattices with defocusing saturable nonlinearity and a fourth-order diffraction property are investigated. When different values are used for the coupling constant of the fourth-order diffraction, the critical threshold of the 2D PT-symmetric optical lattices remains unchanged. The in-phase dipole solitons exist in the first finite gap and are shown to be stable in the moderate power region. The existence and stability of dipole solitons with different fourth-order diffraction coupling constants and different saturation parameters are therefore studied. We also investigate the transverse power-flow vector of these gap solitons.