基于传输矩阵法的表面等离子激元特性分析

Characterization of Surface Plasmon Polaritons in Transfer Matrix Method

针对目前研究表面等离子体波所用电磁场仿真软件的非简便性与非直观性,提出了适用于Matlab等通用计算环境的传输矩阵法。该方法基于电磁场基本理论出发,从两个紧邻层面上的电场和磁场出发,得到传输矩阵,并将单层结论推广到整个介质空间。利用该传输矩阵法,模拟了棱镜-金属膜-感光介质三层结构激发表面等离子激元(SPP)的情况,分析表面等离子的频率与入射光线的角度关系,其计算结果与Shoji Maruo等基于理论推导与实验测量的结果相吻合。同时利用传输矩阵法,分析得出了材料折射率和薄膜厚度等因素对反射光线强度,即能量耦合效果的影响规律。

A novel algorithm was developed to simulate surface plasmonpolarions（SPPs） with the transfer matrix. The transfer matrix was derived in two steps： first,the transfer matrix involving a single layer was derived in terms of the elec-tric and magnetic fields of adjacent layers calculated by solving Maxwell equations; then, the transfer matrix of a single layer was expanded to that of bulk material. The newly-developed algorithmoutperforms the conventional simulations with Ansys, HFSS,and CST because it uses the more convenient and intuitivesoftware package Madab. The impact of light＇s incident angle on the frequency of SPPs was simulated. The simulated results were found to agree well with the calculated and measured data reported by Shoji Maruo et. al. The influence of the refractive index and film thickness on intensity of the reflected light, i. e. the energy coupling efficiency, was also simulated in the novel transfer matrix method.