Staggered differential phase-shift keying format with RZ or CSRZ clock for 100Gbit/s transmission

Two novel optical phase modulation formats, the staggered differential phase-shift keying (SDPSK) with return-to-zero (RZ) and carrier-suppressed return-to-zero (CSRZ) shape, are proposed and compared by numerical simulation for 100 Gbit/s medium-range transmission. RZ-SDPSK and CSRZ-SDPSK signals are generated by cascading two phase modulators and a dual-arm Mach-Zehnder modulator. The demodulation of two phase formats can be achieved on 1 bit rate through only one Mach-Zehnder delay interferometer and a balanced receiver. The transmission performance of the extracted RZ and CSRZ clock signals are compared.