All-optical binary full subtractor using logic operations based on nonlinear properties of semiconductor optical amplifier

Abstract

We propose a new and potentially integrable scheme for the realization of an all-optical binary full subtractor employing two half-subtractors and an additional OR gate. The half-subtractor comprises an XOR gate, an AND gate, and a NOT gate. The XOR gate is realized using semiconductor optical amplifier (SOA)-based Mach–Zehnder interferometer (MZI). The AND, OR, and NOT gates are based on nonlinear properties of semiconductor optical amplifier. The proposed scheme is driven by two input data streams and a borrow bit from the previous less significant bit order position. In our proposed design, we achieve extinction ratios for difference and borrow output signals of 11[Formula: see text]dB and 10[Formula: see text]dB, respectively. Successful operation of the system is demonstrated at 10[Formula: see text]Gb/s return-to-zero modulated signals.