金属透镜的色散时域有限差分法研究

Dispersive finite-difference time-domain analysis of metallic lenses

为克服传统时域有限差分法(FDTD)不能计算色散材料的困难,给出了一种基于Drude模型的色散FDTD算法,并推导出具体的差分公式。将该方法用于模拟金属透镜的聚焦功能,结果与已有理论吻合。本文方法完全适用于分析电导率与频率有关的各种色散材料所构建的光波导。

In order to overcome the numerical divergence of the conventional finite-difference time-domain （FDTD） that has been widely applied to dispersive media, an efficient dispersive FDTD method based on Drude model is presented and the difference formula of dispersive FDTD is deduced in this paper. The method is demonstrated for the analysis of metallic lenses. The result is consistent with the previous theoretical conclusion. The presented method can be used in optical waveguide which is composed of dispersive media.