Soliton Dynamics in a Nonlinear Dual-Core System with a Uniform Bragg Grating and a Bragg Grating with Dispersive Reflectivity

Abstract

The stability and dynamics of solitons are investigated in a dual-core nonlinear system in which a uniform grating is coupled with a non-uniform grating. Quiescent and moving soliton solutions are attained by performing numerical analysis for various system parameters (e.g., dispersive reflectivity, coupling coefficient, detuning frequency and soliton velocity). The existences of quiescent and moving solitons are analysed by investigating their dispersion relation in laboratory and moving frame, respectively. Sidelobes appear in the soliton tails after a moderate dispersive reflectivity value. The effects of and interplay between system parameters on the stability of solitons are also numerically analysed. Additionally, stability diagrams are reported to express the overall stability scenario of solitons. An interesting finding is that the inclusion of dispersive reflectivity causes the stable region to expand into the negative detuning frequencies for both stationary and moving solitons. Next, the interaction dynamics of both in-phase and out-of-phase stationary solitons are investigated. Systematic numerical analysis is performed to investigate the outcomes of interactions between two solitons from the same core and from opposite cores. Numerous interesting outcomes, including the generation of a merger into a stationary or slow-moving soliton, the creation of three solitons, symmetric separation, destruction of solitons, repulsion of solitons and temporary bound state followed by either symmetric or asymmetric separation are observed. Finally, similar to the case of interactions, the outcomes of collision between two moving solitons from the same core and from opposite cores are also investigated for different system parameters.