Research On Photonic Crystal Functional Devices Based On Complete Photonic Band Gap

Due to the rapid improvement of electronic information technology,the development of integrated circuit size has reached the bottleneck of classical physics.As the chip size becomes smaller,electrons as the main carrier of integrated circuits generate thermal effects due to coulomb interaction,which causes a series of problems,such as reduced performance of the integrated circuit,high energy wasted,and slow transmission speed.Photonic crystals are composite materials that use photons as information carriers.For electrons,photons have many advantages and can be used to fabricate integrated optical paths.Due to the excellent research properties and extensive use of photonic crystals,researchers at home and abroad are increasingly focusing on photonic crystals.An important characteristic of photonic crystals is that they have photonic band gaps.There are two kinds of photonic band gaps:full photonic band gap and directional band gap.In the pursuit of complete photonic band gap,people have been working on a large frequency range,and the fabrication of photonic crystal functional devices on this basis has been the goal of people.In this paper,the finite-difference time-domain method is used,people study the waveguide device of two-dimensional photonic crystal plate based on complete photonic band gap and the waveguide device and coupling cavity of ideal two-dimensional photonic crystal design based on complete photonic band gap.The specific content and results are as follows:First,two-dimensional photonic crystal plates exhibiting photonic band gaps in TE-like and TM-like polarization are of particular interest for better control of light propagation and ease of experimental fabrication.By reducing the symmetry of the photonic crystal lattice,it is possible to simultaneously achieve photonic band gaps in TE-like and TM-like polarizations in a specific frequency region.Based on the air holes embeded in the silicon background,two two-dimensional photonic crystal plate structures are proposed,which are respectively arranged circular honeycomb air holes of different sizes,large circles and small triangular air holes.Transmittance indicates that these two structures provide a large full band gap.Different kinds of straight waveguides are designed.By analyzing the light transmittance and spatial field distribution,their ability to localize the incident beam is studied.The light energy is perfectly localized in the optimized waveguide structure.Our proposed photonic crystal slab waveguide is easy to manufacture and can be applied to future all-optical integrated circuits.Secondly,the time-domain finite difference method is used to optimize the structural parameters of the two-dimensional triangular lattice air-hole photonic crystal waveguide,and a large complete photonic band gap is found.The polarization-insensitive photonic crystal waveguide is designed based on the complete photonic band gap.The resulting structure is relatively simple,the working bandwidth is large,and the transmission performance is still maintained.On this basis,the coupling cavity structure is designed so that the two polarization modes of light can pass through the coupling cavity structure at the same time,and can selectively pass through in a certain frequency band.This solves one of the key issues in integrated light path design.