亚波长光栅的衍射效率

本文使用矢量衍射理论一严格的耦合波理论对亚波长光栅的衍射效率进行了数值计算，得到在不同光栅参数时亚波长光栅的衍射效率，对影响光栅衍射效率的各个光栅参数分别进行分析，讨论了光栅在光栅参数变化时的衍射特性，给出衍射效率随光栅各个参数的变化曲线。由结果可知亚波长光栅的衍射效率随光栅槽的深度以及光栅占空比有着规律性的变化，选取不同的光栅参数就可得到完全不同的衍射效率，这样就为设计出所需要的光栅滤波特性提供了制造依据。

Diffraction efficiency of sub-wavelength gratings

This paper calculates the diffraction efficiency of sub-wavelength grating using rigorous couple-wave theory and gets the diffraction efficiencies of sub-wavelength gratings that have different parameters. The paper analyses the grating parameters that influence the diffraction efficiency of the gratings, discusses the diffraction characteristic when grating parameter changes, and gives the trend curve of diffraction efficiency with grating parameters. Calculation results indicate that the diffraction efficiency of sub-wavelength grating changes with the depth of the grating groove and the duty cycle of the grating. Selecting different grating parameters, complete different diffraction efficiencies can be obtained. Therefore, we can design the grating filter characteristic that is needed with this calculation result.