Dark Soliton Solutions For A Coupled Nonlinear Schrodinger System

Under investigation in this paper is the coupled nonlinear Schrodinger system which describes the mode-locked fiber lasers. Based on the Hirota method and Kadomtsev-Petviashvili hierarchy reduction method, N-dark-dark soliton solutions are derived. Features and asymptotic behaviors of dark-dark solitons are analyzed in detail, and typical dynamics has been demonstrated. Both proportional and not proportional single dark-dark solitons in u and v components are studied. Interactions of two dark-dark solitons are demonstrated. We find that there is no energy transfer between the two solitons or between the u and v components before and after the interactions. (C) 2021 Elsevier Ltd. All rights reserved.