Comparison of 100Gb/s transmission performances between RZ-DQPSK and polarization multiplexed NRZ/RZ-DPSK with automatic polarization de-multiplexer

Long-term transmission performances of polarization multiplexed 2x50 Gb/s NRZ/RZ-DPSK signals, denoting good transmission performances but with larger PMD-induced BER fluctuations compared with 100 Gb/s RZ-DQPSK, are successfully observed by constructing an automatic polarization de-multiplexer.