All-optical half adder using single mechanism of XGM in semiconductor optical amplifiers

Abstract

By using gain nonlinearity characteristics of semiconductor optical amplifier, an all-optical binary half adder at 10 Gbps is demonstrated. The half adder operates in single mechanism, which is XGM. The half adder utilizes two logic functions of SUM and CARRY, which can be demonstrated by using the XOR gate and the AND gate, respectively. In the XOR (A NOT B + NOT A B) gate, Boolean A NOT B is obtained by using signal A as a probe beam and signal B as a pump beam in SOA-1. Also, Boolean NOT A B is obtained by using signal B as a probe beam and signal A as a pump beam in SOA-2. By adding two outputs from SOA-1 and SOA-2, Boolean A NOT B + NOT A B (logic XOR) can be obtained. In the AND (AB ) gate, Boolean NOT B is firstly obtained by using signal B as a pump beam and clock signal as a probe beam in SOA-3. By passing signal A as a probe beam and NOT B as a pump beam through SOA-4, Boolean AB is acquired. By achieving this experiment, we also explored the possibilities for the enhanced complex logic operation and higher chances for multiple logic integration.