Simultaneous all-optical demodulation and format conversion for multi-channel (CS)RZ-DPSK signals.

We proposed and demonstrate an all-optical demodulation and format conversion scheme for multi-channel (carrier suppressed) return-to-zero differential phase shift keying ((CS)RZ-DPSK) signals. By utilizing a single delay interferometer (DI) with half bit delay, multi-channel (CS)RZ-DPSK signals can be demodulated simultaneously at the destructive port of the DI, with the corresponding converted nonreturn-to-zero differential phase shift keying (NRZ-DPSK) signals obtained at the constructive port. The proposed multi-channel operation has been demonstrated for 620 Gb/s RZ-DPSK and 640 Gb/s CSRZ-DPSK signals, with ~0.8 and 1.2 dB average power penalties for the format conversions respectively.