Nano-Integrable Optical Logic Gate Implementation in Photonic Crystal Waveguide Using Beam Interference Principle

Abstract

Optical logic gates are the best alternative to low-speed semiconductor-based integrated circuitry. Attractive features like small size, ultrahigh speed, tunability, reduced power consumption, and high selectivity have raised the demand for optical gates to a greater extent. By now research has ensured a promising field for optics-based technologies. However, the best logic gate arrangement is yet to be developed. In this work, a highly efficient photonic crystal waveguide-based structure has been proposed to implement all-optical AND-OR gates. The proposed structure implies the beam interference principle to carry out the logic operations. The proposed structure has a dimension of 8.4 × 5.4 µm2 with silicon nanorods embedded in the air background. Numerical analysis has been done using the Finite Element Method (FEM) in COMSOL Multiphysics software. Performance analysis shows that the optimized structural parameters give a high contrast ratio of 41.24 dB and 30.17 dB for OR and AND gates, respectively. Also, the extinction ratio has been found as high as 37.51 dB and 25.21 dB for OR and AND gates, respectively. These values have surpassed most of the recent works of all-optical logic gates. Simple design, high-performance factors, and compact size make the structure a suitable choice for on-chip integration.