We present a polarization-manipulated multispectral perfect absorber based on a 2D metal/insulator/metal nanocavity array, in which a periodic structure of stacked Au–Al₂O₃ elliptical nanodisk is deposited on a bulk flat Au substrate. Theoretical analysis of the electromagnetic property showed that both the dipolar plasmon resonance and the plasmon cavity mode are the physical origins of the near-perfect absorption. Owing to the azimuthally symmetry breaking, the reflectivity difference can reach up to 90% through an orthogonal rotation of the incident light polarization. In addition, the central wavelength of these absorption bands is highly sensitive to variation of the surrounding liquid sample’s refractive index. This proposed sub-wavelength plasmonic platform with both features of the polarized manipulation and the sensitive sensing may provide promising applications in multi-wavelength filtering and bio-sensing.

中文翻译：

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通过金属/绝缘体/金属椭圆纳米腔阵列实现偏振控制的多光谱完美吸收和灵敏感测

我们提出了一种基于二维金属/绝缘体/金属纳米腔阵列的偏振操纵多光谱完美吸收体，其中周期性的堆叠式Au-Al ₂ O _3结构椭圆形纳米盘沉积在块状平坦的Au衬底上。电磁特性的理论分析表明，偶极等离子体激元共振和等离子体激元腔模都是近乎完美吸收的物理起源。由于方位对称性的破坏，通过入射光偏振的正交旋转，反射率差异可以达到90％。此外，这些吸收带的中心波长对周围液体样品折射率的变化高度敏感。提出的具有偏振操作和灵敏感测功能的亚波长等离子体平台可以为多波长滤波和生物感测提供有希望的应用。