Ultra Compact, High Contrast Ratio Based all Optical OR Gate Using Two Dimensional Photonic Crystals

In this paper, Two Dimensional Photonic Crystals (2DPC) based all-optical two/three input OR gate is proposed and designed. A logic gate is an elementary building block of a digital circuit. The proposed all-optical OR gate is designed by creating Y shaped defect with ring resonator in a hexagonal lattice structure. The performance of the proposed all-optical OR gate is investigated using the Plane Wave Expansion (PWE) and Finite Difference Time Domain (FDTD) method. The functional parameters namely normalized efficiency, contrast ratio, response time and bit rate, are calculated. The proposed all-optical OR gate operates at a wavelength of 1550 nm. The size of the proposed structure is compact in nature. It offers high contrast ratio and minimum delay time. Hence it is suitable for optical processors, high speed optical integrated circuits and switching devices.