色散周期结构的辅助场时域有限差分法分析

Study of periodic dispersive structures using splitfield FDTD method

利用辅助场时域有限差分(FDTD)方法分析色散周期结构的斜入射问题.主要基于Floquet定理,在FDTD迭代式中引入辅助场量,结合变换的周期及吸收边界条件,解决了周期结构斜入射问题的电磁特性仿真.进一步将辅助场FDTD方法引入至色散周期结构的模拟,结合Z变换方法,给出了基于Drude色散模型的具体迭代公式.数值计算结果表明所构建方法的有效性及普适应.

The dispersive periodic structures are simulated by the split-field finite difference time domain （FDTD） method. According to the Floquet theorem, a set of auxiliary elements are introduced into the FDTD iteration to deal with electromagnetic simulation of oblique incidence on periodic structures, by combining the periodic and absorption boundary condition. We here extend the split-field method to the study of periodic dispersive structures by combining the Z transformation method. The iterative equations of the Drude dispersive model are also provided. By Comparing analytical and other numerical results, the efficiency and wide applicability of our method are demonstrated.