Soliton communication beyond the average-soliton regime

We study semianalytically soliton dynamics in a soliton-based communication line for which the amplifier spacing is larger than the soliton period (referred to as the quasi-adiabatic regime). This regime allows us to overcome the limit on the soliton duration (TFWHM , 15 ps) imposed by the average-soliton regime. Our calculations show that periodically stable propagation of short solitons (TFWHM ­ 1–5 ps) is possible for an amplifier spacing ranging from 5 to 20 km. We discuss the dynamical features associated with the propagation of short solitons in the quasi-adiabatic regime and present a simple model capable of predicting the width and the mean frequency of the steady-state soliton. We compare the model with appropriate numerical simulations. Our analysis may also be applied to fiber lasers that produce ultrashort solitons (TFWHM , 1 ps) in a relatively long-cavity configuration.  1995 Optical Society of America