基于晶格效应的光子晶体带隙特性研究

Investigation of Photonic Band Gaps of Two-dimensional Photonic Crystals Based on Lattice Configurations

对10种类型阿基米德晶格按不同晶格点阵进行分类,利用平面波展开法数值计算了光子晶体的能带结构,讨论归一化半径对其带隙的影响,比较了低频带隙相对宽度值.计算结果表明:单胞含多个"原子"的类正方晶格和类三角晶格光子晶体均存在TM模各向同性带隙和低频带隙,还容易产生TE模和TM模的完全带隙,进一步分析发现(32.4.3.4)晶格和(3.6.3.6)晶格打开TM模的低频第1带隙下边界值为最小;选择合适归一化半径分别为0.2和0.26,类正方晶格和类三角晶格光子晶体都能够得到较宽TM模低频带隙的最大值,(32.4.3.4)晶格和(3.6.3.6)晶格获得低频带隙为最宽.典型复式晶格空气环/硅光子晶体能够获得较宽的完全带隙.研究结果为设计新型光学器件提供了理论依据.

Ten types of two-dimensional Archimedean lattices were classified by square-like lattices and triangle-like lattices. Then the properties of photonic band gaps in the photonic crystals were studied by the plane wave expansion method. The effect of the normalized radius on the band gaps is discussed,and the band gap widths of above photonic crystals of lower frequency were compared. The numerical results show that the photonic crystals with square-like lattices and triangle-like lattices have some isotropic band gaps and lower frequency band gaps for the TM modes,the complete band gaps for the TE and TM modes were produced easily. The lower boundary values of first band gap for the TM modes are analyzed is minimal for the （3^2. 4.3.4） and （3.6.3.6） lattices by analysis. The maximum values of those band gaps for the TM modes in the square-like lattices and triangle-like lattices are obtained if choosing an approriate normalized radius 0. 2 and 0. 26, and the typical photonic crystal with compound lattice has complete band gap. The research can pave a way in the design of new optical devices.