不同对称性条件下光子晶体局域态的演化

光子晶体不仅可以用来调控自发辐射,还可以用来控制光的传输和局域.研究采用平面波展开法进行模拟计算.首先改变光子晶体H1缺陷及其附近介质柱的半径,使得光子晶格缺陷处超晶胞的旋转对称性具有C6v,C3v或C2v等点群的性质;然后分析二维圆形介质柱三角光子晶体的局域态在光子禁带中演化.计算结果表明：随着介质柱的半径的变化,光子晶体局域态会发生变化,其演化表现出阶段性;同时随着对称性破缺程度的加深,会有更多缺陷态进入光子禁带.计算选择硅（Si）作为介质柱材料,主要为硅基光子晶体激光器的选模提供理论参考.

The Evolution of the Localized Photonic States in Different Symmetrical Photonic Crystal

Photonic crystal cannot only be used to inhibit spontaneous emission and redistribute the energy into useful forms , but can also be designed to control and confine photon. The evolution of the localized photonic states in different symmetrical photonic crystal super-cells was investigated with the method of plane wave expansion（PWE）. On the one hand, the radius of some dielectric rods at or near the defect H1 was changed simultaneously , to transform the symmetry of the super-cell involving the defect to that of the point group of C6v, C3v or C2v ; On the other hand , the evolution of the localized photonic states was studied. The stimulated calculation results demonstrate that the location of the localized photonic states in the photonic band gap （PBG） depends on the radius of the rods and the evolution of the localized photonic states has its periods and that the amount of the localized photonic states increases with the degree of the relaxation of symmetry increasing . The dielectric cylinder is silicon, and the research is committed to the work of creating the silicon-based nanolaser.