Finite-size effects in wave transmission through plasmonic crystals: A tale of two scales
Finite-size effects in wave transmission through plasmonic crystals: A tale of two scales
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DOI：
10.1103/physrevb.102.075308
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发表时间：
2020-05
影响因子：
3.7
通讯作者：
M. Maier;M. Luskin;D. Margetis
中科院分区：
文献类型：
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作者：
M. Maier;M. Luskin;D. Margetis
我们研究被称为等离子体晶体的层状结构中波传播的光学系数。它们由有限数量的堆叠的金属片组成，这些金属片嵌入在具有亚波长间隔的介质主体中。通过调整层的频率、间隔、数目以及几何形状，这些结构可以在从太赫兹到中红外区域的频率范围内表现出吸引人的传输特性。我们的方法使用了分析和数值方法的混合方法来处理具有无限大、平移不变、平板和纳米带的不同几何形状。我们描述了在零层间距的限制下，平面波在等离子体晶体中的传输，与由均匀产生的总厚度相等的有效介质板的比较。我们从数值上证明了用均匀的等离子体晶体代替离散的等离子体晶体，即使对于相对较少的层数，也可以准确地捕捉到类似于消光光谱的透射率。我们指出了几何相关校正场的作用，它表达了亚波长表面等离子体的影响。特别是，通过使用校正器，我们描述了纳米带几何结构固有的横向共振。
We study optical coefficients that characterize wave propagation through layered structures called plasmonic crystals. These consist of a finite number of stacked metallic sheets embedded in dielectric hosts with a subwavelength spacing. By adjustment of the frequency, spacing, number as well as geometry of the layers, these structures may exhibit appealing transmission properties in a range of frequencies from the terahertz to the mid-infrared regime. Our approach uses a blend of analytical and numerical methods for the distinct geometries with infinite, translation-invariant, flat sheets and nanoribbons. We describe the transmission of plane waves through a plasmonic crystal in comparison to an effective dielectric slab of equal total thickness that emerges from homogenization, in the limit of zero interlayer spacing. We demonstrate numerically that the replacement of the discrete plasmonic crystal by its homogenized counterpart can accurately capture a transmission coefficient akin to the extinction spectrum, even for a relatively small number of layers. We point out the role of a geometry-dependent corrector field, which expresses the effect of subwavelength surface plasmons. In particular, by use of the corrector we describe lateral resonances inherent to the nanoribbon geometry.