85 Gbit/s WDM transmission of 16 5.3 Gbit/s RZ data signals over 7931 km using accurate gain-equalisation and precompensation of group-velocity-dispersion

The authors demonstrate wavelength-division-multiplexing (WDM) transmission of 16 5.3 Gbit/s signals over 7931 km using a non-soliton return-to-zero (RZ) modulation format. In this experiment, a gain equalisation scheme is applied using two types of optical filters to accurately equalise the asymmetric gain profile of an EDFA chain, and a pre-compensation technique of group-velocity-dispersion (GVD) to reduce SPM-GVD penalties. These techniques made the WDM transmission of 16 channels possible without a serious channel imbalance in transmission performance