A second-order transfer function analysis is performed on plasmonic modes with disparate quality factors. This generalized analysis technique is applied to the coupling of modes in metal–insulator–metal structures in the mid-wave infrared, which are systematically studied, both experimentally and with computational modeling. Coupling between these disparate modes is observed from the asymmetric Fano-like lineshape at the resonant crossings in both finite element method simulations and angle dependent spectra. The pole analysis method applied to both experimental and numerical data allows for extraction of the coupling coefficient for this system and is applicable to other plasmonic and photonic coupled resonances.

中文翻译：

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基于极点的金属-绝缘体-金属等离激元结构耦合分析

对具有不同品质因数的等离激元模式进行了二阶传递函数分析。这种广义的分析技术被应用于中波红外中金属－绝缘体－金属结构的模式耦合，这些都是通过实验和计算模型进行系统研究的。在有限元方法模拟和与角度相关的光谱中，从共振交叉处的非对称Fano状线形观察到这些不同模式之间的耦合。应用于实验和数值数据的极点分析方法可以提取该系统的耦合系数，并适用于其他等离子体和光子耦合共振。