320-Gb/s (32 x 10 Gb/s WDM) transmission over 500 km of conventional single-mode fiber with 125-km amplifier spacing

Thirty-two 10-Gb/s channels spaced by 100 GHz are transmitted over 500 km of dispersive fiber (D>+19 ps/nm/spl middot/km) with 125-km amplifier spacing. This is made possible by the use of 3 in-line dual-stage flat-gain erbium-doped fiber amplifiers (EDFAs) incorporating dispersion-compensating fiber. The transmission performance is significantly improved when a 9-km section of dispersion compensating fiber is added at the receiver end, for the longer-wavelength half of the multiplex.