Performance of RZ- versus NRZ-transmission on standard single-mode fibers

The huge amount of standard single-mode fibers installed in terrestrial systems makes the analysis of return-to-zero (RZ) modulation format an interesting proposal, On the basis of computer simulations, we investigate the RZ-transmission for the optimum system performance taking into account the dispersion, Kerr nonlinearity, attenuation and ASE noise, Parameters as bit rate, distance and power levels are estimated for the lowest system degradation, The work considers different duty ratios including NRZ-pulses.