Transmission of 32-WDM 10-Gb/s channels over 640 km using broad-band, gain-flattened erbium-doped silica fiber amplifiers

We report 640-km transmission of 32 wavelength-division-multiplexed (WDM) 10-Gb/s channels with 100-GHz spacing (covering 25-nm bandwidth) using wide dynamic range, gain-flattened erbium-doped silica fiber amplifiers (EDSFAs) with an optical bandwidth of 35 nm. The EDSFA separation is 80 km, the system gain is 140 dB and the total end of system gain nonuniformity among the 32 channels is 4.9 dB.