Long-period oscillations and soliton content of dispersion-managed solitons

A major part of nonlinear optical data transmission happens in fibers with alternating dispersion. Solitons propagating in such fibers are often accompanied by long-period (much longer than the dispersion map) oscillation. In this paper we demonstrate that the long-period oscillations can be traced to the fact that these (dispersion managed, DM) solitons actually are composite objects with constituents of solitary character. Oscillations in a pulse shape are often due to a beating between constituents: see the well-known case of higher-order solitons in a constant-dispersion fiber.