Ag/AAO纳米有序阵列复合结构等效光学参量的确定

引入厚度偏差Δd, 修正了薄膜透射率表达式.基于Ag/AAO纳米有序阵列复合结构实验透射光谱(500—2700nm)的两条极值包络线, 定义了一个优化函数, 结合最优化数值算法尝试确定具有较强吸收的Ag/AAO纳米有序阵列复合结构的等效光学参量. 由此计算了该结构的等效折射率n、等效消光系数k、平均等效厚度d以及厚度偏差Δd. 该方法对Ag/AAO纳米复合结构平均等效厚度的相对计算误差仅为0.3%, 与实测厚度基本一致, 且Ag/AAO纳米复合结构的模拟透射谱与实验透射光谱在500—2700nm波段范围内相符. 这表明该计算方法可有效确定Ag/AAO纳米复合结构的等效光学参量, 并与实验结果是自洽的. 关键词： 薄膜光学 光学参量 纳米复合结构 最优化算法

Determination of optical parameters of ordered Ag/AAO nano-array composite structure

The optical transmission function is modified by taking account of the influence of thickness variation Δd on transmission of thin films. Meanwhile, we introduce an optimization technique and define an evaluating function, such that a simple method is developed based on the envelope curves of the optical transmission spectrum over the wavelength range 500—2700nm at normal incidence, which is used for the determination of the equivalent refractive index n, equivalent extinction coefficient k, average equivalent thickness d and thickness variation Δd of the ordered Ag/AAO nano-array composite structure. The relative error is about 0.3% in the calculation of average equivalent thickness . The simulated transmission of Ag/AAO nano-array composite structure is in satisfactory agreement with the measuremental values. All these results show that with this simple method the optical parameters of Ag/AAO nano-array composite structure can be calculated of accurately and the results are consistent with the experiment.