Research And Application Of Transmission Characteristics Of Two-dimensional Photonic Crystal Cavity

In the era of big data and cloud computing,communication networks and communication devices with faster transmission rates and processing speeds have increased dramatically to meet people’s demand for information.However,traditional communication devices all use semiconductor materials to control the transport of carriers.Photonic crystals can control the transmission of photons almost losslessly.Since photons are single particles,they do not have the advantages of similar Coulomb interactions between electrons.The optical communication devices and integrated devices designed in this way have good research value.The photonic crystal resonator structure is primarily based on architecture and interpretation in this paper.The plane wave expansion method was used to simulate the photonic crystal’s band gap distribution,and the FDTD method was used to simulate the interaction between structural parameter changes and the resonant cavity’s transmission rate.After optimizing the photonic crystal cavity structure,Based on the coupled mode principle,a resonant unit structure is designed to form a photonic crystal wavelength division multiplexer with six channels.Based on the linear interference effect,a hexagonal resonant cavity structure in a triangular lattice is designed to form a photonic crystal all-optical logic NOT gate.As follows:(1)Analysis and research on photonic crystal band gap distribution and resonant cavity transmission characteristics.To begin,the plane wave expansion approach is used to model and analyze the factors that influence the band gap distribution of photonic crystals.Then,the most basic microcavity and ring cavity structure are established,when analyzing the impact of structural parameter shifts on transmittance using the finite difference time domain approach.It is found that without changing the overall size of the ring resonator,the lattice constant of the central dielectric column is reduced,and other relevant principles are that the output propagation peak will pass in the direction of increasing wavelength.It provides guidance for the subsequent research of photonic crystal integrated communication devices.(2)Design and research of photonic crystal wavelength division multiplexer.By combining the microcavity and the ring cavity to form a new coupled resonant unit,the structural parameters of the dielectric cylinder,such as its circumference,are evaluated and optimized.The specification is for a six-channel photonic crystal wavelength division multiplexer with high integration,transmission volume,and low crosstalk.The transmitting characteristic curve and field distribution of the unit were analyzed using the finite difference time domain procedure.Changing the radius of the dielectric column at the output end improves the transmission rate even more,and a reflective cavity structure is constructed on the output waveguide side to reduce the channel crosstalk.(3)Design and research the photonic crystal logic NOT gate is controlled by all optical signals.Based on the linear interference effect,a hexagonal resonant cavity structure is designed in the triangular lattice photonic crystal,so that the light waves transmitted in the resonant cavity have constructive or destructive interference.Therefore,the all-optical logic non-function with fast response speed and high contrast is realized,and specific parameters such as contrast and response time are obtained by simulation analysis.