Ultra-Compact Multifunctional All-Optical Logic Gate Based on Asymmetric Photonic Crystals Multi-Mode Interference

Abstract

An all-optical logic gate based on a 3 x 3 photonic crystal multimode interference (PC-MMI) was proposed and analyzed. PC-MMI can operate as NAND, NOT, NOR, and OR gates by switching the optical signal to different input waveguide ports, either simultaneously or individually. The short MMI length and width turn out to be 64 and 4.8 mu m, respectively. The gap between the two line-defect waveguides is 1.2 mu m. It has a 1/10 smaller size than conventional MMI optical logic devices, which are close to 1 mm.