The Imaging And Focus Function Of The Special Diffracton Screen

According to the diffraction theory, we can find thecorresponding and approximate solution to deal with imageformation by diffraction screen.In the theory of Fourier optics, it ismainly Fourier transform and Fractional Fourier transform.In theview of diffraction theory, it is mainly Frannhofer diffraction andFresnel diffraction.In Geometrical optics,image formation can besimply stated as little correspondence that monocentric beam isnot destroyed. In diffraction theory, image formation can be simplyconsidered as principal maximum formed by Frannhofer diffractionor Fresnel diffraction.That is" image point ". Previous research onimage formation by diffraction screen, the major concern was theimpact on the diffraction image with the different distances of thediffraction screen and corresponding to a different diffractionpattern, and Frannhofer diffraction corresponding to Fouriertransform,Fresnel diffraction corresponding to Fractional Fouriertransform through the study of light going by the diffraction. Most ofthe studies are based on the diffraction screen.They barely focus onthe nature of the diffraction screen.This paper focus on the imagingfunction of diffraction screen from another perspective, mainly theimpact of physical properties and even imaging caused by thegeometric properties of diffraction screen itself. This paper summarizes the geometric properties of specialfunctions and their corresponding optical physics to prepare for thestudy of the diffraction screen geometric properties. Secondly,there is a review of Kirchhoff diffraction theory and RayleighSommerfeld diffraction theory. Based on the scalar diffractiontheory, diffraction process with different distance from viewingscreen to diffraction screen corresponds to different diffractiontypes, respectively, the Fresnel diffraction and Frannhoferdiffraction. The two kinds of diffraction’s corresponding suitablecondition also provide theoretical basis for the imaging by the samediffraction screen.The corresponding diffraction types may beprovided with the change of the position of the viewing screencorresponding to the different diffraction approximation.At last,there is specific analysis on corresponding imaging ofspecial diffraction screen. The results show that diffraction screenwith different transmittances corresponds to different physiognomyposition. There is a certain relationship between transmittance ofdiffraction system and focal length by studying the correspondingrelation between the thin lens imaging and focal length. And we canfind their focal length by mathematical reasoning, then find thecorresponding focal length through comparing to the transmittanceof thin lens. The results show the unity of the two methods. Basedon the theory above-mentioned,the author verifies the reliability ofthe results using computer simulations.