(FD)~2TD计算金属表面场增强

本文首次利用依赖于频率的时域有限差分法(FD)2TD来计算隐失波激励下金属粒子表面的场增强。首先,利用(FD)2TD计算了三维球形银粒子的表面场增强,与国外文献11]中用不同方法对此问题的计算结果进行了对比,结果较为相符,说明我们自己编写的(FD)2TD程序是可信的。然后,利用此程序计算了在全内反射条件下,处于介质板上纳米尺度边长的正三角形银粒子表面的场增强,给出了该正三角形银粒子三角端点存在场增强的所谓"热点"并给出了该处的场增强值随样品距离的变化曲线。

A Frequency - Dependent Finite - Difference Time- Domain Formulation for Metallic Surface Field Enhancement

In this paper we computed the metallic surface field enhancement in use of a frequency-dependent finite-difference time-domain formulation. At first, to confirm our program for this formulation, we have computed surface field enhancement of three-dimension sphere silver particle, and compared it with the result made in literature. The field distribution in near-field of equilateral triangle silver particle with nanometer scale, excited with p-polarized evanescent wave, was computed. The result gives the field enhancement in the "hot spot", and its variety versus the distance from the sample surface.