Validity of effective medium theory for metal-dielectric lamellar gratings
Validity of effective medium theory for metal-dielectric lamellar gratings
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金属介电层状光栅有效介质理论的有效性
DOI：
10.1016/j.optcom.2011.05.001
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发表时间：
2011-09-01
影响因子：
2.4
通讯作者：
Wang, Zhi-Guo
中科院分区：
文献类型：
--
作者：
Kang, Xiu-Bao;Tan, Wei;Wang, Zhi-Guo
采用精确模式分析方法，研究了横向磁极化作用下金属-介质层状光栅的有效介质理论（EMT）描述。结果表明，除了一个低阶本征模可以近似为有效模外，还有一个高阶本征模不能用EMT描述。两种本征模之间的耦合引起的高阶本征模的共振增强导致EMT失效。在材料吸收的情况下，高阶本征模将被抑制，从而有效介质近似变得适用。这一结果澄清了EMT的模糊识别。(C)2011爱思唯尔有限公司版权所有。
The effective medium theory (EMT) description of metal-dielectric lamellar gratings under transverse magnetic polarization is studied by the exact mode analysis method. It is demonstrated that, except a lower order eigenmode which can be approximated as the effective mode, there is a higher order eigenmode that cannot be described by the EMT. The resonant enhancement of the high order eigenmode induced by the coupling between the two kinds of eigenmodes leads to the failure of the EMT. In the presence of material absorption, the higher order eigenmode will be suppressed and thus the effective medium approximation becomes applicable. This result clarifies the fuzzy recognition about EMT. (C) 2011 Elsevier B.V. All rights reserved.