六角形散射子光子晶体的界面态

Guide Modes in Photonic Crystal Heterostructures Composed of Hexagon Air Rods in Two-dimensional Lattices

研究采用平面波展开加超元胞方法计算了正方格子六角形空气散射子二维光子晶体镜面对称异质结的界面态经过研究发现,这种异质结界面态可以通过相对于界面横向拉开或者纵向错开而产生,并且调节到绝对带隙中成为传导模界面态的个数和变化规律在很大程度上依赖于光子晶体异质结构的几何和物理参量通过对比我们发现与圆柱形散射子相比,在六角形散射子异质结中更易于产生传导模。

The interface states in absolute photonic band gap (PBG) of photonic crystal heterostructures composed of two semi infinite two dimensional photonic crystals, in which the hexagon air cylinders set on the square lattices are studied.The PC structures of this heterostructures are calculated by use of the plane wave expansion method in combination with a super cell technique.The calculated results show that there are some interface states appearing in the absolute PBG in the mirror symmetric heterostructures when the lattice is separated from the interface or slipped along the interface , the width of absolute gap and the number of the interface states depend on the geometric and physical parameters of the heterostructures. Comparing the results of hexagon cylinders with that of both square and circular cylinders, the property of hexagon cylinders is superior to circular cylinders, and inferior to square cylinders. It is believed that this result is due to the symmetry of hexagon cylinders that is between both circular and square.