Application of semiconductor optical amplifier logic gates in high-speed all-optical pattern recognition

In this paper, we propose and demonstrate a novel all-optical pattern recognition system. The system is able to detect and locate a specified target pattern within an input data sequence at high line-rate. The key elements of the system are an all-optical XNOR logic gate and an all-optical AND gate, the latter forming part of a recirculating loop. Both these gates are based on semiconductor optical amplifiers (SOAs). Arbitrary 8-bit target patterns at 10.65 and 21.3 Gbit/s are successfully recognised and located using three SOA-based logic gates.