Dispersion-managed soliton in fiber links with in-line filtering presented in the basis of chirped Gauss–Hermite functions

Abstract

Applying the complete basis of chirped Gauss–Hermite functions, we present a theory of dispersion-managed (DM) solitons in communication systems with in-line filtering. In specific practical example we show that a DM soliton can be well described by a few modes in such an expansion (with the zero Gaussian mode), justifying the use of a Gaussian trial function in the previously developed variational approach. The method presented here is a regular way to estimate the accuracy of the approximate variational approach. An analytical formula to describe the dependence of excess gain on filter bandwidth and map parameters is derived. It is shown that use of the filters additionally increases the peak power of a DM soliton compared with that of a DM system without in-line filtering. The suggested expansion also presents a systematic method to account for the effect of practical perturbations. Theoretical results are verified by numerical simulations.