Proposal for all-optical switchable OR/XOR logic gates using sum-frequency generation

All-optical logic gate based on parametric processes in periodically poled lithium niobate (PPLN) waveguides is a promising technique in future high-speed all-optical signal processing. A simple realization of switchable OR/XOR logic gates at 40 Gb/s is proposed and numerically demonstrated using sum-frequency generation in a PPLN waveguide. By appropriately adjusting the input signal power and choosing the waveguide length, OR and XOR logic gates can be obtained. The operation performance is simulated, including eye diagrams and Q-factor. The input signal powers and waveguide length are optimized, providing a theoretical basis for achieving the optimal performance for the switchable OR/XOR logic gates.