20-Gb/s PDM-RZ-DPSK Transmission With 40 krad/s Endless Optical Polarization Tracking

An endless polarization tracker detects and minimizes interchannel interference, enabling automatic optical polarization demultiplex and consecutive direct detection of a 20-Gb/s polarization division multiplex RZ-DPSK signal at polarization scrambling speeds up to 40 krad/s. Transmission over 430 km of fiber is error-free.