Asymmetric surface plasmon resonances revisited as Fano resonances
Asymmetric surface plasmon resonances revisited as Fano resonances
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DOI：
10.1103/physrevb.97.235437
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发表时间：
2018-06
影响因子：
3.7
通讯作者：
D. Nesterenko;S. Hayashi;Z. Sekkat
中科院分区：
文献类型：
--
作者：
D. Nesterenko;S. Hayashi;Z. Sekkat
在奥托和Kretschmann配置中获得的平面金属-电介质结构的衰减全反射光谱表现出由于表面等离子体激元的激发而引起的共振凹陷。虽然倾角具有不对称的线形，但不对称性没有受到太多的关注，并且洛伦兹对称线形通常用于光谱分析。基于电磁场理论和耦合模理论，分析了两层和三层等离子体系统的反射谱，证明了非对称线型可以看作是Fano线型。在共振区，使用我们的近似表达式计算的Fano线型的光谱与严格的电磁计算得到的结果非常一致。本配方的反射率使我们能够深入了解等离子体共振的特性行为的物理起源。
Attenuated total reflection spectra of planar metal-dielectric structures obtained in the Otto and Kretschmann configurations exhibit resonance dips due to excitation of surface-plasmon polaritons. Although the dips have asymmetric line shapes, the asymmetry has not received much attention and the Lorentzian symmetric line shape has commonly been used in the spectral analyses. We analyze the reflectivity spectra of two- and three-layer plasmonic systems based on the electromagnetic and coupled-mode theories, and demonstrate that the asymmetric line shapes can be regarded as the Fano line shapes. In the resonance region, the spectra calculated as Fano line shapes using our approximate expressions are in excellent agreement with those obtained by rigorous electromagnetic calculations. The present formulations of the reflectivity allow us to gain insight into physical origins of characteristic behavior of the plasmonic resonances.