WDM transmission at 6-Tbit/s capacity over transatlantic distance, using 42.7-Gb/s differential phase-shift keying without pulse carver

We report the transmission of a record 6 Tbit/s capacity over 6120 km distance, involving channels modulated at 42.7-Gb/s bit-rate with differential phase-shift keying (DPSK). The performance is found similar to DPSK with subsequent pulse carving, namely RZ-DPSK.