Zhou Fei, Liu Ye, Cai Weiping
Opt Lett. 2014 Mar 1;39(5):1302-5. doi: 10.1364/OL.39.001302.
In this Letter, a novel hybrid nanoparticle array with huge local electric field intensity enhancement is proposed theoretically. The hybrid array is constructed by replacing some nanodisks with nanobowties from a perfect nanodisk square array. In our structure, the nanodisk array, which acts as a two-dimensional grating, can efficiently excite surface plasmon polaritons (SPPs) modes, whose electric field is much larger than the incident light. Then the SPPs mode excites the localized surface plasmon resonance (LSPR) mode of the nanobowties. When the resonant peaks of the array and the nanobowties coincide, the nanobowties are strongly excited, and the maximum intensity enhancement factor (E/E0)2 as large as 4.2×10(6) is achieved. A two-step excitation model is proposed to help us to understand the underlying physical mechanism for this enhancement. This hybrid array structure shows great potential in highly sensitive surface enhanced Raman scattering and fluorescence detection.
在本信函中，从理论上提出了一种具有巨大局部电场强度增强效果的新型混合纳米粒子阵列。该混合阵列是通过从完美的纳米盘方形阵列中用纳米蝴蝶结替换一些纳米盘来构建的。在我们的结构中，充当二维光栅的纳米盘阵列能够有效地激发表面等离激元极化激元（SPPs）模式，其电场远大于入射光。然后，SPPs模式激发纳米蝴蝶结的局域表面等离激元共振（LSPR）模式。当阵列和纳米蝴蝶结的共振峰重合时，纳米蝴蝶结被强烈激发，实现了高达4.2×10(6)的最大强度增强因子（E/E0）2。提出了一种两步激发模型来帮助我们理解这种增强的潜在物理机制。这种混合阵列结构在高灵敏度表面增强拉曼散射和荧光检测方面显示出巨大潜力。
