Generating dark solitons through cross-phase modulation in optical fibers

Abstract

Dark solitons evolving from a dark pulse, which is induced on a long pulse in the normal group-velocity dispersion range by a bright pulse in the anomalous dispersion range through cross-phase modulation in a single-mode fiber, are numerically observed. In most situations dark-soliton evolution is observed after the copropagating bright pulse is filtered. The number of evolving dark solitons and their parameters, including the depth, shifting speed, and shifting direction, are controlled by the intensity and phase profiles of the induced dark pulse at the position where the bright pulse is filtered. The parameters of the induced dark pulse depend on those of the input bright pulse, the relative speed between the input bright pulse and the long pulse, and the position where the bright pulse is filtered. We obtain numerical results by using the beam-propagation method to solve the coupled nonlinear Schrodinger equations. A dark soliton that was almost a black soliton was generated.