Robustness of one-dimensional photonic band gaps under random variations of geometrical parameters
Robustness of one-dimensional photonic band gaps under random variations of geometrical parameters
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DOI：
10.1103/physrevb.72.195101
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发表时间：
2005-06
影响因子：
3.7
通讯作者：
H. S. Sozuer;K. Sevim
中科院分区：
文献类型：
--
作者：
H. S. Sozuer;K. Sevim
用超晶胞方法研究了一维光子晶体中光子带隙随层厚随机扰动的变化。给出了平面波和解析态的能带结构和态密度的计算结果，以及随随机性水平和超晶胞尺寸的增加而产生的传输系数。结果表明，当超晶胞尺寸固定在1024个晶胞时，随着随机性的增加，较高的带隙首先消失。发现最低带隙一直持续到55%的随机性水平。然而，随着超晶胞尺寸的增大，观察到所有带隙都接近伪隙，但态密度很低。结果表明，分布在光子带隙中的大部分模是由相对较小的密集缺陷团簇的谐波引起的。
The supercell method is used to study the variation of the photonic bandgaps in one-dimensional photonic crystals under random perturbations to thicknesses of the layers. The results of both plane wave and analytical band structure and density of states calculations are presented along with the transmission coefficient as the level of randomness and the supercell size is increased. It is found that with the supercell size fixed at 1024 unit cells, higher bandgaps disappear first as the randomness is gradually increased. The lowest bandgap is found to persist up to a randomness level of 55%. However, as the supercell size is increased all bandgaps are observed to approach pseudogaps but with very low density of states. It is shown that harmonics of a relatively small cluster of closely spaced defects largely account for the bulk of the modes that populate the photonic bandgaps.