Analysis of the extreme scattering effect for particles inside and above a noble metal film via the discrete sources method
Analysis of the extreme scattering effect for particles inside and above a noble metal film via the discrete sources method
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DOI：
10.1088/2040-8978/14/1/015001
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发表时间：
2012-01-01
影响因子：
2.1
通讯作者：
Wriedt, Thomas
中科院分区：
文献类型：
--
作者：
Eremina, Elena;Eremin, Yuri;Wriedt, Thomas
本文应用离散源法分析了玻璃棱镜上沉积的金膜内和金膜上粒子的极端散射效应。极端散射效应是P偏振激发的散射强度急剧增加的效应，其发生在临界角之后的倏逝波区域。此外，强度增强不仅出现在透射方向上，而且出现在后向散射方向上。该效果不依赖于金属膜的厚度或颗粒直径，但它受到膜材料的强烈影响。不同的散射特性，如透射截面和反射截面及其相关的表面等离子体共振膜，本文进行了研究和讨论。分析了在粒子和金膜之间加一层薄的透明间隔层对散射特性的影响。微分散射截面被认为是检查在前向和后向散射方向上的场分布。
In this paper the discrete sources method is applied to analyze the extreme scattering effect for particles located both inside and on a gold film deposited on a glass prism. The extreme scattering effect is an effect of the sharp increase of the scattered intensity for P-polarized excitation which occurs in the evanescent wave region behind the critical angle. Moreover, the intensity enhancement appears not only in the transmission direction but in the backscattering direction as well. The effect does not depend on the thickness of the metal film or particle diameter, but it is strongly affected by the film material. Different scattering characteristics, such as transmission cross section and reflection cross sections and their correlation with the surface plasmon resonance in the film, are investigated and discussed in this paper. The analysis of the influence of a thin transparent spacer layer between particle and gold film on the scattering characteristics has been performed. The differential scattering cross section is considered to examine the field distribution in the forward and backscattering directions.