基于介质圆柱结构的复式二维光子晶体禁带研究

为提高二维光子晶体禁带带宽或产生完全禁带, 利用平面波展开法对二维正方排列介质圆柱和三角排列介质圆柱结构以及改变其晶胞形成的复式结构进行了禁带研究。研究结果表明, 对于介质柱结构, 实现禁带中心频率低频化的方式有两种, 即增大介质柱半径和增加介质柱折射率。当采用复式结构时, 一般可形成较大的TM(Transverse Magnetic)禁带, 同时为TE(Transverse Electric)禁带和完全禁带的形成提供了可能。通过改变晶胞结构, 破坏结构对称性是实现完全禁带的一种可行方法。

Research of Band Gap in Compound Two-Dimensional Photonic Crystal Based on Dielectric Cylinder Structure

In order to quest for large band gap or complete band gap of two-dimensional photonic crystal, the band gap of the structure in two-dimensional square lattice and triangular lattice with dielectric cylinder using the plane wave method, and the band gap of the compound structure by changing the unite cell are studied. Results show that to the dielectric rod, the middle frequencies of the band gap will reduce with the increase of the radius and refractive index of the dielectric rod. The compound dielectric cylinder structure has big TM(Transverse Magnetic) band gap, and it makes TE(Transverse Electric) band gap and the formation of this make complete band gap be possible. Changing the unite cell to reduce the symmetry of the structure is a feasible method to quest for complete band gap.