40-Gbit/s fiber optic transmission systems: are solitons needed?

A numerical program was developed to simulate the performance of fiber optic transmission systems and its accuracy was verified by comparisons between the calculated results and experiment data. Using this program, soliton transmission and dispersion compensation schemes at 40 Gbit/s were compared. It was shown that by using dispersion compensation, linear transmissions over 3000 km with non-return to zero (NRZ) and over 4000 km with return to zero (RZ) data forms are possible. Without special soliton transmission control techniques, single channel soliton transmission has no advantage over dispersion compensation transmission.