Mixed-type vector solitons of theN-coupled mixed derivative nonlinear Schrödinger equations from optical fibers

Abstract

We investigate the mixed-type vector solitons of the $N$-coupled mixed derivative nonlinear Schr\odinger ($N$-CMDNLS) equations from optical fibers. Mixed-type ($m$-bright-$n$-antidark or $m$-bright-$n$-dark) vector-soliton solutions are derived via the Hirota method. Such vector solitons are found to be independent of the sign of cubic nonlinearity in the $N$-CMDNLS equations, which is different from the case of the coupled nonlinear Schr\odinger equations. The parameter conditions for the shape-preserving and shape-changing collisions of the mixed-type vector solitons are also given by an asymptotic analysis. As an example, the mixed-type vector-soliton collisions in the 3-CMDNLS equations are graphically illustrated. Those results may be useful to the ultrashort-pulse propagation in nonlinear fibers.