PPLN-based all-optical 40 Gbit/s three-input logic AND gate for both NRZ and RZ signals

Abstract
Reported is an all-optical high-speed three-input logic AND gate using cascaded sum- and difference-frequency generation (cSFG/DFG) in a periodically poled lithium niobate (PPLN) waveguide. The converted idler wave via cSFG/DFG carries the AND result of the three-input signals. PPLN-based 40 Gbit/s three-input logic AND operations for both non-return-to-zero (NRZ) and return-to-zero (RZ) signals are successfully demonstrated in the experiment.