HERMITE-GAUSSIAN EXPANSION FOR PULSE-PROPAGATION IN STRONGLY DISPERSION MANAGED FIBERS

We represent a pulse in the strongly dispersion managed fiber as a lin ear superposition of Hermite-Gaussian harmonics, with the zeroth harmo nic being a chirped Gaussian with periodically varying width. We obtai n the same conditions for the stationary pulse propagation as were obt ained earlier by the variational method. Moreover, we find a simple ap proximate formula for the pulse shape, which accounts for the numerica lly observed transition of that shape from a hyperbolic secant to the Gaussian. Finally, using the same approach, we systematically derive t he equations fur the evolution of a pulse under a general perturbation . This systematic derivation justifies the validity of similar equatio ns obtained earlier from the conservation laws. [S1063-651X(98)10211-8 ].