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.
© 2000 Optical Society of America
(060.2330) Fiber optics and optical communications : Fiber optics communications
(060.4510) Fiber optics and optical communications : Optical communications
(060.5530) Fiber optics and optical communications : Pulse propagation and temporal solitons
Zhi M. Liao, C. J. McKinstrie, and Govind P. Agrawal, "Importance of prechirping in constant-dispersion fiber links with a large amplifier spacing," J. Opt. Soc. Am. B 17, 514-518 (2000)