“Hot spots” induced near-field enhancements in Au nanoshell and Au nanoshell dimer
“Hot spots” induced near-field enhancements in Au nanoshell and Au nanoshell dimer
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DOI：
10.1007/s00340-009-3535-7
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发表时间：
2009-05
期刊：
影响因子：
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通讯作者：
Dajian Wu;Dajian Wu;Ying Cheng;Xiaojun Liu
中科院分区：
文献类型：
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作者：
Dajian Wu;Dajian Wu;Ying Cheng;Xiaojun Liu
用有限元方法研究了“热点”对Au纳米壳和Au纳米壳二聚体近场性质的影响。结果表明，随着针孔半径R的增大，针孔平行于偏振方向的Au纳米壳层的近场增强最大值从17.906 ATR=0 nm增加到36.979 ATR=0.8 nm，且几乎与半径无关。在垂直于极化方向的针孔内也可以观察到较大的电场，电场强度随针孔半径的增大而增大。金纳米壳层二聚体的近场强烈地依赖于入射光的偏振和传播方向。二聚体结内电场的最大增强随二聚体间距的变化呈现出指数衰减特性。此外，当针孔位于两个纳米壳层之间的间隙附近时，在两个Au纳米壳层之间的交界处存在非常强的电场。
The influence of “hot spots” on the near-field properties of Au nanoshell and Au nanoshell dimers have been investigated by means of the finite element method. It is found with increasing the pinhole radiusRthat the maximal enhancement of near-field for Au nanoshell with pinhole parallel to the polarization increases from 17.906 atR=0 nm to 36.979 atR=0.8 nm, and then almost shows a negligible radius dependence. Large electric fields also can be observed inside the pinhole perpendicular to the polarization, which increases with increasing the pinhole radius. The near-field of Au nanoshell dimer depends strongly on the polarization and propagation directions of the incident light. Exponential decay behavior is found for the maximal enhancement of the electric field in the dimer junction as a function of the dimer separation. Furthermore, a very strong electric field is found in the junction between two Au nanoshells when the pinholes are located near the gap between the nanoshells.