Interaction dynamics of Bragg grating solitons in a semilinear dual-core system with dispersive reflectivity

Abstract

The interactions of quiescent Bragg grating (BG) solitons in a semilinear dual-core system, where one core is nonlinear and is equipped with a BG with dispersive reflectivity and the other core is linear are investigated. It has been previously shown that the model supports stable quiescent solitons which may or may not have sidelobes in their profiles. The interaction of in-phase solitons can lead to various outcomes such as generation of two moving solitons with equal or unequal velocities, merger of solitons into a quiescent one, generation of three solitons (one quiescent and two moving ones) and destruction of solitons. The presence of sidelobes can radically change the interaction dynamics, e.g. in-phase solitons can repel or form a temporary bound state which subsequently splits into two separating solitons. We have identified the outcome regions for in-phase interactions through systematic numerical simulations in the plane of dispersive reflectivity vs. frequency. We have also analysed the effect of initial separation on the outcomes of interactions. It is found that when sidelobes are present in solitons’ profiles, the outcomes of the interactions are strongly dependent on the initial separation.