Optimal preprocessing of pulses for dispersion management

Abstract

We demonstrate that a single extra cell composed of normal- and anomalous-dispersion fibers with specially selected lengths is sufficient to cast a standard input pulse (Gaussian, including a chirped one, or a raised-cosine pulse) into a properly shaped dispersion-managed (DM) soliton, which allows its subsequent stable transmission in an indefinitely long DM link. Together with the lengths of the fibers in the shaping cell, the optimization procedure developed in this work selects the peak power and temporal width of the input pulse. The considered systems may or may not include in-line filters, as well as higher-order effects, namely, the third-order dispersion and intrapulse stimulated Raman scattering. It is shown that, while the optimal preprocessing secures stable transmission of the pulses, their “raw” counterparts suffer serious degradation if directly launched into the same system. Robustness of the scheme against deviations of the shaper’s parameters from their optimal values is also investigated. The preprocessing stabilizes multisoliton strings too and helps solitons to withstand effects of optical noise. In addition, the preprocessed solitons, unlike the untreated ones, collide in a nearly elastic fashion.