变栅距光栅的衍射效应与特性分析  

Diffraction Effect and Characteristic Analysis of Varied-Line-Space Grating

作　　者：赵金雨 罗逸文 何晴 梁衍瑞 黎俊晨 翁嘉文 ZHAO Jinyu;LUO Yiwen;HE Qing;LIANG Yanrui;LI Junchen;WENG Jiawen(School of Electronic Engineering(School of Artificial Intelligence),South China Agricultural University,Guangzhou 510000,China)

机构地区：[1]华南农业大学电子工程学院(人工智能学院),广东广州510000

出　　处：《大学物理实验》2024年第4期43-50,共8页Physical Experiment of College

基　　金：华南农业大学校级教改项目(JG20142);华南农业大学校级一流课程项目(224415)。

摘　　要：变栅距光栅夫琅禾费衍射图样中高频信息和低频信息的混叠现象将会导致无法分析获得对应结构特征参数。为解决这一问题,实验方案从原理上借助条纹分析中具备局域分析特性的伸缩窗口傅里叶变换思想,结合夫琅禾费衍射原理,对变栅距光栅衍射图样进行理论分析推导,建立局部光栅衍射强度分布特征与结构参数的关系。然后在传统夫琅禾费衍射光路系统中,通过引入宽度可调谐的狭缝充当窗函数,对变栅距光栅进行分割以及局部光栅衍射图样分析。最后,基于MATLAB自主开发数值分析软件系统,进行数值仿真以及光学实验分析,根据对应的衍射强度分布特征,实现对变栅距光栅结构特征参数的检测。实验对三种变栅距光栅的衍射效应与特性进行了研究分析,根据实验拍摄的衍射图样成功获得变栅距光栅结构特征参数,并与将其理论数值仿真结果对比,误差分析表明本方案是合理可行的。It fails in the analysis of the structural parameters of the varied-line-space grating because of the spectrum aliasing phenomenon in the Fraunhofer diffraction patterns.To overcome this problem,the experimental scheme relies on the principle of dilating window Fourier transform with local analysis characteristics in stripe analysis and the Fraunhofer diffraction principle,to theoretically derive and establish the relationship between the characteristics of local varied-line-space grating diffraction pattern intensity distribution and the corresponding structural parameters.For the designed optical system,a slit with tunable width is introduced into the traditional Fraunhofer diffraction optical system as a window to obtain the local varied-line-space grating,and to perform localization analysis.Finally,a numerical analysis system is developed based on MATLAB to perform the numerical simulation and the optical experimental analysis by ourselves.According to the characteristics of the diffraction intensity distribution,the structural parameters of the local varied-line-space grating can be obtained.There are three types of varied-line-space grating are employed for experimental analysis.The structural parameters of the local varied-line-space grating are achieved successfully by the captured diffraction patterns.Furthermore,the comparison with the theoretical numerical simulation results,and the error show that the analysis results are reasonable and feasible.

关 键 词：变栅距光栅 夫琅禾费衍射 窗口傅里叶变换 MATLAB 

分 类 号：O436.1[机械工程—光学工程]