3.2 Tbit/s (40 /spl times/ 80 Gb/s) transmission over 1000 km with 100 km span (25 dB loss) and 0.8 bit/s/Hz of spectral efficiency

We demonstrated 3.2 Tb/s (40 ch /spl times/ 80 Gb/s) signal transmission over 1,000 km of TrueWave-RS fiber with 100 km span (25 dB loss) by the use of newly developed tandem electroabsorption modulators, LiNbO/sub 3/ modulators, hybrid Raman/EDFA, dynamic gain equaliser filters, and passive filtering to suppress the linear cross talk. An optimum dispersion map was incorporated to further relax the nonlinearity based impairment on the system.