The coexistence of double Fano interference originating from anti-phased and in-phased lattice resonances is observed in a novel plasmonic lattice array, which being consists of a horizontal double-stacked rectangular metal-insulator block. Based on a classic model analysis of coupled harmonic oscillators, the observed double Fano interference is revealed as a result of the interaction between a bright broad resonance and a dark narrow one as well as the coupling of narrow and broad spectral lines. This allows for active tuning of the double Fano resonance to a desired spectral position by a controlled size variation of the metal-insulator block arrays. After optimizing the parameters, they display two narrow absorbance peaks with high-quality factors of 84.92 and 214.1, respectively. This is because of the utmost enhancements of local electric fields in the gap between two opposing rectangular metal blocks. We expect that double Fano interference character may gain more significant potential applications in biomedical sensing.

中文翻译：

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金属绝缘子块阵列中的双Fano干扰的观察

在新型等离子晶格阵列中观察到了由反相和同相晶格共振引起的双重Fano干扰共存，该等离子体等离子体阵列由水平的双堆叠矩形金属绝缘体块组成。根据耦合谐波振荡器的经典模型分析，由于明亮的宽谐振和暗的窄谐振之间的相互作用以及窄谱线和宽谱线的耦合，揭示了观察到的双重Fano干扰。这允许通过金属-绝缘体块阵列的受控尺寸变化将双法诺共振主动调谐到期望的光谱位置。优化参数后，它们显示两个窄的吸收峰，其高质量因子分别为84.92和214.1。这是因为两个相对的矩形金属块之间的间隙中的局部电场得到了最大程度的增强。我们预计，双Fano干扰特性可能会在生物医学传感中获得更重要的潜在应用。