Novel ultrafast all-optical XOR scheme based on Sagnac interferometric structure

A novel scheme of all-optical XOR is proposed based on Sagnac interferometric structure. Using a semiconductor optical amplifier (SOA) as nonlinear medium, the operations of this scheme with 80 Gb/s return to zero pseudorandom bit sequence are simulated correctly with fairly high performance. Through numerical analysis, and by comparison of the performances between 40 and 80 Gb/s operation, parameters of the SOA and the signals are discussed, and this scheme is proved to exceed the speed limitation imposed by carrier lifetime of the SOA. This scheme is potentially capable of XOR operation speed to >100 Gb/s.