Propagation of highly chirped pulses in fiber-optic communications systems

The propagation of strongly chirped pulses in an amplified fiber-optic comm unications system is experimentally investigated, Spectral narrowing of the pulses is observed. The narrowing is attributed to interplay between the i nitial chirp and the nonlinearity in the transmission line. Four-wave mixin g (FWM) between wavelength channels is found to be similar to that for unch irped nonreturn-to-zero (NRZ) pulses. Low error rate transmission over 720 km is achieved using these chirped pulses, which are generated by a transmi tter based on a mode-locked fiber laser.