二维六方柱光子晶体特性研究

通过平面波展开法对二维六方介质柱（空气孔）光子晶体带隙理论进行了分析，仿真发现带隙的变化与晶格常数的具体取值无关，而只与其填充比有关。三角晶格的这种光子晶体的带隙特性最好，并对空气孔之间产生交叠情况下的带隙特性进行了分析说明。随着介质柱（空气孔）与背景折射率差值的增大，光子晶体的带隙会逐渐变宽，而且带隙的位置也会向低频移动。用FDTD法对四方晶格的二维六方柱光子晶体波导透射特性进行了仿真，仿真结果表明其与波导的带隙结果吻合。

Analysis of the Characteristic for 2D Hexagon Column Photonic Crystals

Band gap theory of two-dimensional hexagon column （air hole） pnotonic crystals is analyzed with planar wave ex-pansion method. From the analysis of the simulation, it is concluded that the change of band gap is only related to the fill factor not to the crystal lattice constant. Band gap of the tri-angle lattice structure is the best. When the air holes are over-lapped, the reason of the band gap appearance is explained. As increasing of the difference of the background refraction and the column （air hole） refraction, band gap will be wider and its position will also shift to the lower frequency. Transmission characteristic of two-dimensional square lattice hexagon column photonic crystal waveguide is simulated with FDTD, and its superposition with the waveguide band gap is observed.