任意亮度孔形衍射的数值模拟

Numerical simulation of aperture diffraction with arbitrary brightness

本文基于Matlab软件平台,通过编写程序来处理惠更斯-菲涅耳公式.利用图片像素实现各种孔形光源的亮度值,再用Matlab循环计算光屏上复振幅分布,可简单快速地实现任意形状及亮度孔的近场和远场衍射图案的数值模拟,给出任意形状和任意亮度孔的衍射图案.模拟近场衍射特性时,衍射图像中央存在光强减弱、增强两种情况,验证了近场衍射到远场衍射的过程中央光强变化逐渐减少;模拟正多边形孔衍射特性时,验证了当正多边形的边数趋于无穷大时,衍射图像为圆孔衍射;最后,给出任意形状和任意亮度孔的衍射图案.

Based on Matlab software platform, the Huygens Fresnel formula is processed by programming. The brightness values of various aperture light sources are realized by using picture pixels, and the complex amplitude distribution on the light screen is calculated by Matlab cycle. The numerical simulation of near-field/far-field diffraction pattern of arbitrary shape and brightness aperture can be realized simply and quickly, and the diffraction pattern of arbitrary shape and brightness aperture are given. In the process of near-field diffraction to far-field diffraction, the change of central light intensity gradually decreases(from Fresnel diffraction to Fraunhofer diffraction);in the process of simulating the diffraction characteristics of regular polygon hole, it is verified that when the number of regular polygon edges tends to infinity, the diffraction image is circular hole diffraction;finally, a numerical example is given for diffraction pattern of arbitrary shape and brightness hole.