Abstract:  Based on the diffraction characteristics of cosine gratings, Fourier analysis is applied to discuss the diffraction pattern of a transmission grating. The diffraction field is the same as the grating diffraction law obtained by the traditional interference diffraction analysis method. The quantitative relationship between grating diffraction field and grating structure is summarized, and a unified method for analyzing grating diffraction is concluded, which is significant for students to correctly understand grating diffraction.

Key words: grating, diffraction, Fourier transform