Optimum fiber dispersion for two-step dispersion-allocated optical soliton, RZ at zero GVD and NRZ systems

Abstract
The optimum fiber dispersion conditions for two-step dispersion-allocated (D-A) optical soliton and nonreturn-to-zero (NRZ) systems are derived numerically. The transmission speed is 20 Gb/s, the amplifier spacing is SO km, and the two fiber segment lengths are 30 km and 50 km. The maximum transmission distance for a D-A soliton system can be obtained at an average dispersion of 0.1 ps/km/nm. The dispersion of the first fiber segment is 3.1 ps/km/nm. For an NRZ system, the maximum transmission distance can be obtained at zero average dispersion, in which the dispersion of the first segment is -2 ps/km/nm. The optimum average dispersion strongly depends on the dispersion allocation and on whether a soliton or an NRZ system is used.