Mixed-type soliton solutions for the N-coupled higher-order nonlinear schrödinger equation in optical fibers

Under investigation in this paper are the N-coupled higher-order nonlinear Schrödinger (NLS) equation, which describes the simultaneous N nonlinear wave propagation in a fiber medium with higher order effects. Through the Hirota method, mixed-type one- and two-soliton solutions are obtained. Elastic and inelastic interactions between m-bright-n-dark (m+n=N) solitons are derived through the asymptotic analysis. As an example, the oblique interactions and the bound states of the two-bright-one-dark and one-bright-two-dark solitons for 3-NLS equations are analyzed graphically.