Single-channel transmission in dispersion management links in conditions of very strong pulse broadening: Application to 40 Gb/s signals on step-index fibers

The dynamic behavior of single-channel transmission on standard fibers with strong dispersion management has been theoretically and numerically analyz ed. A single pulse and a pseudorandom pulse sequence have been compared in order to highlight the relevant role played by pulse interaction. A semiana lytical theory of the bandwidth evolution demonstrates that the introductio n of prechirp is very important for controlling the single pulse propagatio n and numerical results show that such a chirp also permits to limit the no nlinear pulse interaction when other pulses are present. Simulations of a 4 0 Gb/s return-to-zero (RZ) system operating in links encompassing step-inde x fibers, by adopting a periodical compensation of the chromatic dispersion have been performed and results show that a record distance of 1300 km can be achieved with an amplifier spacing of 100 km. A compensation of the fib er third order dispersion would extend the transmission to 1800 km, which c orresponds to the limits imposed by the amplified spontaneous emission (ASE ) noise of the optical amplifiers.