二维复合三角格子光子晶体FDTD带隙结构分析

Analysis on PBG Structure of Two-Dimensional Composite Triangular Photonic Crystal by Using FDTD Method

设计一种二维复合三角晶格结构光子晶体,采用时域有限差分法数值计算了这种光子晶体的带隙结构。计算结果表明,介质圆柱在空气中按复合三角形排列存在E偏振和M偏振模完全重叠的光子带隙区,即具有绝对光子带隙。绝对光子带隙的宽度与介质柱的介电常数有关,介电常数差越显著越有利于形成绝对光子带隙,且绝对光子带隙向近红外波段移动。

A composite triangular lattice photonic crystal is designed in this paper, the bandgaps of photonic crystal are studied by FDTD method. The calculated results obviously show that the crystal constructed from dielectric rods in the air background can generate a common band gap, which is called absolute photonic band gap, for both orthogonal polarization E and H. The absolute band-gap width is related to dielectric constants of the cylinders. The large differences between the dielectric constants of the cylinders and the air are useful to form the abslute photoric band gap, and the absolute photonic bandgaps move toward infrared wave.