The Research Of Logic Gate Based On Photonic Crystal

Photonic crystal is an artificial periodic dielectric structure with a feature of photonic forbidden band gap and photonic crystal has been used in various occasions. The method to research photonic crystal have Plane Wave Expansion Method(PWE), Finite Difference Time Domain(FDTD), Transfer Matrix Method(TMM), and Scattering Matrix Method(SMM) and so on. PWE and FDTD are main methods used in this thesis to research photonic crystal. Photonic crystal waveguide and photonic crystal resonant cavity can be constructed by introducing different kinds of defect in integrated photonic crystal. Compared with traditional optical waveguides photonic crystal waveguide could transmit signals with low power consumption in the corner. And photonic crystal waveguide has high quality factor and energy density due to low consumption and narrow resonance spectrum. These advantages have made photonic crystal attracted more and more attention and widely used in all optical communication networks.In this thesis the concept, feature and application of photonic crystal, photonic crystal waveguide and photonic crystal resonant cavity have been study. Photonic crystal forbidden band gap and factors which affect the range and distribution of band gap have been simulated by PWE and FDTD. The main factors which affect the range and distribution of band gap include lattice structure, relative refractive index, polarization mode, shape and radius of dielectric rods. How these factors affect band gap have also been analyzed. Moreover the application of photonic crystal ring resonator and study the resonance characteristic, coupling characteristic and output characteristic curve of three channels and four channels photonic crystal ring resonator also have been researched.Finally a brief introduce of the development and basic principle of all optical logic gate have been made. And two new all optical logic gates based on photonic crystal ring resonator have been proposed. The proposed all optical logic gates have small size, short response time, high contrast ratio and high extinction ratio.