Ultrabroadband Light Absorption by a Sawtooth Anisotropic Metamaterial Slab
Ultrabroadband Light Absorption by a Sawtooth Anisotropic Metamaterial Slab
复制标题
锯齿各向异性超材料板的超宽带光吸收
DOI：
10.1021/nl204118h
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发表时间：
2012-03-01
期刊：
影响因子：
10.8
通讯作者：
Fang, Nicholas X.
中科院分区：
文献类型：
--
作者：
Cui, Yanxia;Fung, Kin Hung;Fang, Nicholas X.
提出了一种由锯齿状各向异性超材料制成的超宽带薄膜红外吸收体。在很宽的频率范围内，正常入射下的吸收率高于95%，其中半最大值时的全吸收宽度约为86%。这种特性在很宽的入射角范围内也能很好地保持。波长较短的光被捕获在宽度较小的锯齿的上部，而波长较长的光被捕获在宽度较大的锯齿的下部。这种现象可以用各向异性超材料波导中的慢光模式来解释。本研究可应用于光伏器件和热辐射器的设计领域。
We present an ultrabroadband thin-film infrared absorber made of sawtoothed anisotropic metamaterial. Absorptivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption width at half-maximum is about 86%. Such property is retained well at a very wide range of incident angles too. Light of shorter wavelengths are harvested at upper parts of the sawteeth of smaller widths, while light of longer wavelengths are trapped at lower parts of larger tooth widths. This phenomenon is explained by the slowlight modes in anisotropic metamaterial waveguide. Our study can be applied in the field of designing photovoltaic devices and thermal emitters.