Femtosecond pulse propagation in optical fibers: higher order effects

Higher-order effects in femtosecond-pulse propagation in optical fibers are examined. In particular, the specific contributions to nonlinear chirping in the fiber by the higher-order cubic dispersion term and by the shock term are investigated. The effects on the output spectrum of fiber input pulses having an initial chirp and an initial asymmetric pulse shape are also investigated. By comparison to a global description, it is shown that, for optical pulses having reasonable power levels, dispersion effects can be accurately approximated by a Taylor series expansion in the nonlinear Schrodinger equation even for pulses containing two optical cycles. >