Dark–bright semi-rational solitons and breathers for a higher-order coupled nonlinear Schrödinger system in an optical fiber

Abstract

Optical-fiber communication is an indispensable part of the modern communication. In this letter, we study a higher-order coupled nonlinear Schrödinger system, which describes the simultaneous propagation of two electric fields in an optical fiber. We construct the Nth-order dark–bright semi-rational soliton solutions for the mixed interactions, and the Nth-order breather solutions for the focusing interactions, where N is a positive integer. For the mixed interactions, we show the first- and second-order dark–bright semi-rational solitons. For the focusing interactions, we present the first- and second-order Y-shaped breathers, and the line-shaped breather with one component possessing an anti-eye-shaped breather and the other component containing an eye-shaped breather, as well as the second-order breather with each component consisting of two curved breathers.