Single-channel 5.12 Tbit/s (1.28 Tbaud) DQPSK transmission over 300 km using non-coherent Nyquist pulses.

We present a single-channel 5.12 Tbit/s polarization-multiplexed DQPSK transmission over 300 km at 1.28 Tbaud using a non-coherent Nyquist pulse. An ultrafast OTDM demultiplexer for 1.28 Tbaud Nyquist pulses was newly developed with a mode-locked fiber laser operating in the L band as a control pulse source. Thanks to the high PMD tolerance of Nyquist pulses, a 300 km transmission was successfully demonstrated for the first time at such a high symbol rate.