Surface gap solitons in linear coupling combined with cubic and saturable nonlinearity

Abstract

We demonstrate the existence and stability of surface gap solitons under linear coupling combined with cubic and saturable nonlinearity by linear stability analysis and real-time evolution. Our results show that both the coupling coefficient and the depth of the well can influence the brightness of the interference fringes. During the collision of surface solitons, phase changes cause the interference pattern to evolve in four distinct ways. As the coupling coefficient and potential well depth increase, the interference patterns of multi-peak solitons become more pronounced. For multi-peak solitons, the interference pattern of the cubic and saturable nonlinear terms can exhibit the same interference intensity.