Ground states of dispersion-managed nonlinear Schrodinger equation

An exact pulse for the parametrically forced nonlinear Schrodinger equation (NLS) is isolated. The equation governs wave envelope propagation in dispe rsion-managed fiber lines with positive residual dispersion. The pulse is o btained as a ground state of an averaged variational principle associated w ith the equation governing pulse dynamics. The solutions of the averaged an d original equations are shown to stay close for a sufficiently long time. A properly adjusted pulse will therefore exhibit nearly periodic behavior i n the time interval of validity of the averaging procedure. Furthermore, we show that periodic variation of dispersion can stabilize spatial solitons in a Kerr medium and one-dimensional solitons in the NLS with quintic nonli nearity. The results are confirmed by numerical simulations.