Nonlinear pulse propagation in dispersion decreasing fibers

By numerically solving the nonlinear Schrodinger equation, we analyze pulse propagation through dispersion decreasing optical fibers (DDFs) in which the core radius varies along the length of the fiber; this in turn leads to a variation of dispersion as well as mode effective area along the length of the fiber. We calculate an optimum core radius profile required to create a local balance between group velocity dispersion and self-phase modulation, so that the DDF can support the propagation of fundamental "soliton" pulses. The variation in the optimum profile corresponding to variations in the fiber parameters has also been analyzed. (C) 2004 Elsevier B.V. All rights reserved.