Propagation of ultrashort optical pulses for nonconservative systems with higher order effect

The complex Ginzburg-Landau equation with three higher order terms (third-order dispersion, Kerr dispersion and self-frequency shift), which can describe the propagation of an ultrashort (subpicosecond or femtosecond) optical pulse in optical fibre systems is studied. Stable propagation of a soliton-like bright pulse is obtained numerically not only in negative and zero group velocity dispersion domains but also in the positive group velocity dispersion domain. The main features of these optical pulses and the parameter regions where they exist are presented. In addition, it is found that in the positive group velocity dispersion domain, a bright pulse would change into a dark pulse under some special parameter conditions.