160-Gb/s (8 x 20 Gb/s WDM) 300-km Transmission With 50-km Amplifier Spacing and Span-by-Span Dispersion Reversal

Capacity upgrades in future lightwave systems can be accomplished either by increasing single-channel bit rates [1,2], or by wavelength multiplexing (WDM) high speed channels [3]. In this paper we report results of experiments in which eight WDM channels each operating at 20 Gb/s were transmitted through 300 km of fiber. Four-photon mixing penalties were suppressed by using fibers with finite dispersion, and chromatic dispersion penalties were avoided by reversing the sign of dispersion in adjacent amplifier spans.