Phase shift of plasmons excited by slits in a metal film illuminated by oblique incident TM plane wave
Phase shift of plasmons excited by slits in a metal film illuminated by oblique incident TM plane wave
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DOI：
10.1117/12.803469
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发表时间：
2008-11
期刊：
影响因子：
--
通讯作者：
Guangyuan Li;A. Xu
中科院分区：
文献类型：
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作者：
Guangyuan Li;A. Xu
金属薄膜中光学光与亚波长结构之间的相互作用引起了人们对表面等离子激元（SPPs）的极大兴趣。解释这些现象的一种有效方法是利用激发的SPP与入射波之间的相移。许多理论和实验研究表明，这种近似于π的位移在正常入射下是固有的。本文对斜入射时的相移进行了分析，并首次用于解释传输效应。用矢量有限元法建立了二维散射的简化公式。模拟结果表明，在较大的入射角范围内，相移可以近似于π。通过这种位移，实现了斜入射下增强或抑制spp传输和相应的相消干涉的条件。讨论了不满足这些条件时入射角的传输效应及其潜在的应用前景。
The interactions between the optical light and sub-wavelength structures in metal film have sparked great interest on surface plasmon polaritons (SPPs). One effective way to interpret these phenomena is to make use of the phase shift between the SPP excited and the incident wave. Many theoretical and experimental studies have shown that this shift approximate to π is intrinsic at normal incidence. In this paper, the phase shift at oblique incidence is analyzed and used to interpret the transmission effect for the first time to our knowledge. A simplified 2D scattering formulation using vector finite element method is set up. Simulations show the phase shift can be approximate to π over a large range of incidence angles. With this shift, the conditions for the enhanced or suppressed transmission and the corresponding destructive or constructive interference of SPPs at oblique incidence are achieved. The transmission effect for incidence angle not satisfying these conditions, as well as its potential applications is also discussed.