Implementation of all-optical quaternary Hadamard gate using 2D photonic crystal

In this paper, the implementation of an all-optical quaternary Hadamard gate based on two-dimensional photonic crystal is proposed. The proposed structure consists of hexagonal lattice of silicon (Si) rods embedded in air background. Simple line defects have been used to design the proposed structure. The required phases at the outputs have been obtained by choosing appropriate optical path lengths. The structure has been simulated by utilizing plane wave expansion and finite difference time domain methods. From the simulation results, different functional parameters, such as rise time, fall time, delay time, response time, bit rate etc. have been obtained. The structure is very simple as well as compact and it offers a fast response time along with a high bit rate, which makes it suitable to be used in optical computing, data processing and high speed optical integrated circuits.