All-optical logic performance of quantum-dot semiconductor amplifier-based devices

The performances of all-optical logic gates AND, OR, XOR, and NOT, based on quantum-dot semiconductor optical amplifier (QD-SOA) devices, are simulated. The saturation power, optical gain, and optical phase response of a QD-SOA is analyzed numerically using a rate-equation model of quantum dots embedded in a wetting layer. The calculated response is used to model the performance of the logic gates. The impact of the injection current and the input-signal power on the system's quality factor are studied. For the parameters used in this paper, all-optical logic gates using QD-SOA are capable of operating at speeds of ∼250 Gb/s.