160 Gbit/s (8 × 20 Gbit/s WDM) 300 km transmission with 50 km amplifier spacing and span-by-span dispersion reversal

Abstract
Eight WDM channels each operating at 20 Gbit/s (231–1 PRBS NRZ) were transmitted through 300 km of fibre with 50 km amplifier spacing. To minimise four-photon mixing effects, fibres with nonzero dispersion were used. Dispersion penalties were avoided by changing the sign of dispersion on adjacent spans.