Chirped bright solitons for Chen-Lee-Liu equation in optical fibers and PCF

We present new types of bright soliton solutions with nonlinear chirp for a derivative nonlinear Schrödinger model incorporating group velocity dispersion and self-steepening nonlinearity. The model known as the Chen-Lee-Liu equation is one of the important modified nonlinear Schrödinger models which has many applications in nonlinear optical fibers and plasma physics. By means of the coupled amplitude-phase formulation, we derive a nonlinear differential equation with a fifth-degree nonlinear term describing the evolution of the wave amplitude in the nonlinear system. The amplitude equation is then solved to obtain three new types of chirped bright soliton solutions, illustrating the potentially rich set of localized solutions of the model. The nonlinear chirp associated with these soliton structures is shown to be directly proportional to the wave intensity and includes both linear and nonlinear contributions. Parametric conditions on system parameters for the existence of the chirped soliton structures are also reported.