矩形光栅衍射效率的一般表达式及其缺级现象

The General Formula to the Diffraction Efficiency of Rectangular Grating and its Phenomenon of Missing Orders

在标量衍射理论基础上,采用透过率函数的傅里叶级数展开和复振幅的傅里叶变换方法给出了计算斜入射下矩形光栅衍射效率的一般表达式;分析了矩形光栅衍射光谱中出现缺级现象的机理,并归纳出了缺级与占空比的关系式。同时,通过数值算例阐述了VCD、DVD和CD ROM信号读出头光栅和用于制作光纤光栅的相位掩模板在理论设计与具体应用上的差别。

The general formula to the diffraction efficiency of rectangular grating that can be used in the oblique angle was presented by using Fourier expansion to the transmission function and Fourier transfer to the plural amplitude.Deeper analysis of the theory on the phenomenon of missing orders in the diffraction spectrum of rectangular grating was made and the relation between the missing orders and the duty cycle was summarized.Meantime a example that explains the difference between the grating in the optical pickup head of VCD,DVD,and CDROM and the phase mask in the optical fiber grating in the theoretic design and applications was described by numeric calculation.