Importance of prechirping in constant-dispersion fiber links with a large amplifier spacing

This is the authors' abstract. We don't add key points for this paper.

We use the variational method to find the optimum launch conditions that can sustain path-averaged solitons in a periodically amplified, constant-dispersion, optical communication system even when amplifier spacing is comparable to or larger than the dispersion length. We determine the amount of prechirping and the initial peak power required and show that both the pulse width and the chirp recover their initial values at each amplifier. The prechirped solitons are different from the standard solitons in constant dispersion since their width and chirp are allowed to vary over each amplifier section. This feature results in an interesting regime in which amplifier spacing can exceed the dispersion length. Numerical solutions of the nonlinear Schrödinger equation show that the use of prechirped solitons improves stability in comparison with guiding-center solitons in constant-dispersion fiber links.