Ultrafast passive all-optical full function logic gates on micro-silicon-on-insulator waveguide chip

Ultrafast passive all-optical full-function logic gates (FLOGs), such as AND, NOT, XOR, XNOR, and OR gates, are studied and designed. FLOGs can be realized only by changing the state of input ports in a designed micro-Sagnac waveguide ring unit. The whole chip is internally passive with unified off-chip source fabricated on a silicon-on-insulator substrate. The transmission performance of FLOGs waveguide ring and integrated chip unit are investigated by both the finite-difference time-domain method and beam propagation method. The research shows that FLOGs have the advantages of low power (μW) consuming, multifunctional, and high transmission rate. The simulated device cascades are indicated that the FLOG structure can be well cascaded, which may be used to form the neural network element. There will be potential applications in all-optical communication networks and large-scale integration circuits in the future.