All-Optical Logic Minterms for Three-Input Demodulated Differential Phase-Shift Keying Signals at 40 Gb/s

The 40-Gb/s all-optical logic minterms generation of three input demodulated return-to-zero differential phase-shift-keying signals is demonstrated based on two delayed interferometers and a semiconductor optical amplifier cascaded with two bandpass filters. Experimental demonstration verifies the logic integrity of this scheme. The final results are derived in the on-off keying format with clear open eyes and extinction ratios over 10 dB. The proposed scheme could be extended to realize arbitrary complex logic gates.