Abstract
The higher-order multiple-scale asymptotic analysis is carried out for the Gabitov–Turitsyn equation that governs the propagation of dispersion-managed solitons through optical fibers. The averaged equation, with the consideration of higher-order terms, provides an in-depth understanding of the soliton propagation through an optical fiber. The polarization preserving fibers as well as birefringent fibers are considered in this paper. Finally, the study is extended to the case of multiple channels, namely dispersion-flattened fibers.