6.4-Tb/s (160×42.7 Gb/s) transmission with 0.8 bit/s/Hz spectral efficiency over 32×100 km of fiber using CSRZ-DPSK format

Carrier-suppressed, return-to-zero differential-phase-shift-keyed modulation format with strong signal filtering and balanced detection are employed to transmit one-hundred-sixty 40-Gb/s, 50-GHz-spaced channels over 3200 km of TrueWave REACH fiber, a record capacity x distance product of 20 Pbit/s-km for terrestrial 40-Gb/s systems.