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.