Abstract: 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 dif- fraction 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 dif- fraction，the change of central light intensity

gradually decreases ( from Fresnel diffraction to Fraunhofer diffrac- tion) ; 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 nu- merical example is given for diffraction pattern of

arbitrary shape and brightness hole.

Key words: Huygens Fresnel principle, Matlab simulation, near field / far field diffraction, arbitrary brightness hole, arbitrary shape hole