Unrepeatered transmission of 21.4-Gb/s (2×10.7-Gbaud) RZ-DQPSK over 220km of SSMF using heterodyne detection and electrical dispersion compensation

Unrepeatered transmission of 21.4-Gb/s RZ-DQPSK over 220km of SSMF using heterodyne detection and electrical dispersion compensation achieving FEC-limit performance in a single-span is reported. The 2-dB CD and DGD tolerance is 577ps/nm and 29ps, respectively.