The variable-coefficient Korteweg-de Vries equation that governs the dynamics of weakly nonlinear long waves in a periodically variable dispersion management media is considered. For general bit patterns, an analytic expression describing the evolution of the timing shift produced by nonlinear...

The propagation of few-cycles optical pulses in a collection of two-level atoms is investigated beyond the traditional slowly varying envelope approximation. It is shown that in certain conditions, a femtosecond pulse can evolve into a stable spatiotemporal optical soliton.