3.2-Tb/s (40 ch*80 Gb/s) transmission with spectral efficiency of 0.8 b/s/Hz over 21 * 100 km of dispersion-managed high local dispersion fiber using all-Raman amplified spans

We report transmission of 3.2-Tb/s (40 ch *80 Gb/s) signals over 21*100 km of high local dispersion-managed fiber with 0.8-b/s/Hz spectral efficiency. The test system incorporated a tandem electroabsorption modulator, all-Raman amplified UltraWave fiber spans, a polarization insensitive dynamic gain equalization filter 40-Gb/s electrical time-division-multiplexing (ETDM) transmitters, a 40-Gb/s ETDM receiver, and a recirculating loop. The dispersion map was designed to minimize the impairment caused by optical nonlinearities.