Persistent oscillations of scalar and vector dispersion-managed solitons

We show that both orthogonal and parallel internal modes exist on the backg round of a dispersion-managed (DM) soliton in randomly birefringent fibers. The orthogonal modes exist for arbitrarily small values of the dispersion map strength, while the parallel modes exist only when the map strength exc eeds a certain threshold value. We demonstrate that initial perturbations o f a DM soliton's profile that consist of one or more internal modes, exhibi t nearly stable oscillations over very long propagation distances, before d ecaying into radiation. (C) 2000 American Institute of Physics. [S1054-1500 (00)00303-7].