The evolution of poise of arbitrary initial form with chirp in weakly nonlinear dispersion fiber

With the success in linear dispersion compensation techniques, a new limitation, nonlinearity, will accumulate when the length of the fiber link increases. In this paper, we obtain the series solution of a nonlinear Schrodinger equation (NLS equation) in the frequency domain, suitable for pulses of arbitrary initial form with chirp. We derive the evolution of the spectrum of a Gauss pulse with chirp in this fiber when only considering the first-order initial nonlinearity, and the approximate formula of the broadening factor without chirp. Finally, the figures of spectrum, pulse form, and broadening factor versus distance, dispersion nonlinearity and chirp are given.