Generalized Darboux transformation, solitonic interactions and bound states for a coupled fourth-order nonlinear Schrödinger system in a birefringent optical fiber

Abstract

The optical fiber communication system is one of the components of a supporting system in the modern Internet fields. Under investigation in this paper is a coupled fourth-order nonlinear Schrödinger system, which describes the ultrashort optical pluses in a birefringent optical fiber. By virtue of the existing Lax pair, generalized Darboux transformation, two- and three-soliton solutions are derived, with respect to the polarization components of the electric field. Based on such solutions, we graphically display (1) the elastic interactions between/among the two/three solitons on a zero-intensity background, where amplitudes of the solitons remain unchanged; (2) the inelastic interactions between/among the two/three solitons, where amplitudes of the solitons change; (3) the bound state among the three solitons; (4) the higher-order linear and nonlinear effects, represented by β, on the polarization components of the electric field: The interval between two peaks becomes smaller and the numbers of the peaks increase when the value of β increases; The three solitons move along the positive time direction when the value of β decreases; The distances between the adjacent peaks become smaller when the value of β increases.