透射型亚波长二元闪耀光栅的数值模拟与分析

Numerical Simulation and Analysis of Transmission Sub-wavelength Binary Gratings

使用OptiFDTD对透射型亚波长二元闪耀光栅的透射场进行了数值模拟;使用FFT方法对电磁场分量进行分析,得到其各个级次的能量分布,进而分析了亚波长结构二元光栅的各个参数对衍射性能的影响。分析结果证实:透射型亚波长二元闪耀光栅可将正入射的TE波闪耀到+1级,且等分数对衍射角影响很小。给定波长,其设计主要由光栅周期、光栅材料折射率和等分数这3个参数决定。

OptiFDTD and Fast Fourier Transform method are used to simulate and analyze the diffracted field of transmission sub- wavelength binary gratings （TSBG）. And the influence of grating parameters on the diffraction efficiency is numerically analyzed. The analysis result demonstrates that, for TSBG, the normal incident TE mode beam can be diffracted to the ＋ 1st order, the interval number has few influence on diffracted angle, the performance of a TSBG is determined by the grating period, material index and interval number for a given wavelength.