All-optical 40 Gbit/s CSRZ-DPSK logic XOR gate and format conversion using four-wave mixing

Abstract

We report simultaneous logic XOR gate for carrier-suppressed return-to-zero differential phase-shift keying (CSRZ-DPSK) and format conversion from CSRZ-DPSK to return-to-zero differential phase-shift keying (RZ-DPSK) by exploiting non-degenerate four-wave mixing (FWM) in a highly nonlinear fiber (HNLF). We derive analytical solutions to complex amplitudes under non-depletion approximation to show the principle of operation and verify the CSRZ-DPSK logic XOR gate and format conversion by theoretical analyses. Three converted idlers are obtained by three non-degenerate FWM processes. All-optical 40 Gbit/s simultaneous multicasting CSRZ-DPSK logic XOR gate and CSRZ-DPSK to RZ-DPSK format conversion are successfully demonstrated in the experiment.