阶梯透射光栅衍射效率的研究

阐述了标量近似与Snell定律和Fresnel关系相结合的方法,并推导出阶梯透射光栅的衍射场强分布和衍射效率公式。以四阶梯透射光栅为例,详细分析计算了衍射效率及其影响因素。研究表明所得结果优于纯标量近似的结果。该方法避免了完全矢量波理论的麻烦,克服了标量近似的不足,特别适宜于研究周期大于4λ的光栅的衍射。对周期小于4λ的光栅,本方法的使用受到了限制。

Study of Diffraction Efficiency of Step Transmission Grating

A method uniting the scalar approximation with the Snell's law and the Fresnel relations is presented in detail. Two formulae of the energy flux density and the diffraction efficiency are derived for the step transmission grating. As a example of application, the diffraction efficiency and the factors influencing on them are analyzed and calculated for the transmission grating with 4 steps. The results show that it is excellent for the gratings of d>4λ, because this kind of the method can not only avoid the complexity of the complete arrow wave theory, but also overcome the insufficiency of the pure scalar approximation. It isn't suitable for the gratings of d<4λ.