对称性破缺Au-ITO-Ag纳米核壳的光学特性研究

Optical properties of symmetry-breaking Au-ITO-Ag multilayer nanoshells

以对称性破缺Au-ITO-Ag纳米核壳结构为研究对象,采用有限元法系统研究其LSPR消光特性的影响因素及变化规律,运用等离激元杂化理论对其LSPR现象进行解释。研究结果表明:纳米核壳的消光特性对入射光偏振方向极其敏感;当入射光偏振方向垂直和平行于对称轴方向时,横向模式︱ω_⊥〉和轴向模式︱ω_//〉可产生多个偶极和高阶共振模式;通过改变Au内核的半径,3层纳米核壳的LSPR共振模式可调谐至近红外区域,在生物传感器和选择性滤波器应用方面潜力巨大。

The extinction properties of symmetry-breaking Au-ITO-Ag multilayer nanosheUs were investigated systematically based on the finite element method, and the influence factor and change rule of LSPR properties were studied. The LSPR phenomenon of Au-ITO-Ag multilayer nanoshells was explained by using the theory of plasmon hybridization. The numerical results indicate that the extinction properties of the muhilayer nanoshells are sensitive to the orientation of the nanoshells with respect to polarization of the light. When the electric field is perpendicular and parallel to the axis of symmetry, the transverse coupling︱ω⊥〉 and axial coupling ︱ω//〉 of symmetry-breaking Au-ITO-Ag multilayer nanoshells provide multiple dipole modes and higher-order modes. By changing Au core radius, LSPR modes of muhilayer nanoshells can be easily tuned into the near-infrared region. The adjustable optical properties of nanoshells may provide potential applications ranging from biological sensors to selective filters.