Path-averaged chirped optical soliton in dispersion-managed fiber communication lines

We present a comprehensive path-average theory of dispersion-managed (DM) o ptical pulse. Applying complete basis of the chirped Gauss-Hermite orthogon al functions, we derive a path-average propagation equation in the time dom ain and present an analytical description of the breathing dynamics of the chirped DM soliton. This theory describes both self-similar evolution of th e central, energy-containing core and accompanying nonstationary oscillatio ns of the far-field tails of an optical pulse propagating in a fiber line w ith an arbitrary dispersion map. In the case of a strong dispersion managem ent the DM soliton is well described by a few modes in this expansion, just ifying the use of a Gaussian trial function in the previously developed var iational approach. Suggested expansion in the basis of chirped Gauss-Hermit e functions presents a regular way to describe soliton properties for arbit rary dispersion map and to account for the effect of practical perturbation s (filters, gratings, noise an so on) on the dynamics of the ideal DM solit on. We also present path-averaged propagation model in the spectral domain that could be useful for multichannel transmission applications. Theoretica l results are verified by numerical simulations. (C) 1999 Published by Else vier Science B.V. All rights reserved.