摘要衍射干涉技术作为一种高精度的干涉测量手段，在精密测量方面有着广泛的应用空间。本文以点衍射干涉仪中的针孔为研究对象，研究了针孔的尺寸与离焦因素对衍射场光强分布的影响。 

通过对标量衍射理论的研究，以理想入射光波为讨论对象，给出衍射光强与针孔尺寸和离焦量之间的关系。在数值计算阶段，通过MATLAB编写了衍射光强计算程序，模拟F =10和F =5的两个光学系统，令入射光波长 ，分别仿真了d=1.6um，2.5um，4.0um，6.3um，10um的针孔直径与不同针孔离焦量产生的衍射光强分布。由仿真结果可知：(1)对于F =10的光学系统，最佳针孔直径为d=6.3um，横向可调焦深为 ，轴向可调焦深为 0.4256mm ；(2)对于F =5的光学系统，最佳针孔直径为d=4.0um，横向可调焦深 ，轴向可调焦深为 0.1064mm 。对实验工作有一定的指导意义。63010

毕业论文关键词  点衍射干涉仪  衍射光强  标量衍射理论  针孔尺寸  离焦

Title  Distribution of the diffraction intensity from the pinhole part in the point diffraction interferometer 

Abstract As a means of high precision in interferometry ,point diffraction interferometer’s tech- nology has a wide range of applications in precise measurement.In this paper, point diffraction interferometer’s pinhole as research object, researches the distribution of diffraction field intensity from the pinhole’s size and defocusing amount .

Through the study of scalar diffraction theory ,we focus on the ideal incident light wave,and give out the relationship between the diffraction intensity and the pinhole’s size as well as defocusing amount.In the numerical calculation stage, making a di- ffraction intensity’s calculation program to simulate two optical systems with F/10 and F/5 by MATLAB. Making the wavelength .Calculating the distribution of diffraction intensity with different pinhole diameters including1.6um, 2.5um, 4.0um, 6.3um and 10um and different pinhole defocusing amounts.Through the simulation results we can know that :(1)In the optical system with F/10, the optimum pinhole diameter is 6.3um, lateral depth of focus is ,axial depth of focus is  ; (2)In the optical system with F/5, the optimum pinhole diameter is 4.0um, lateral depth of focus is ,axial depth of focus is  . It has a certain guiding significance on experimental works.

Keywords   point diffraction interferometer  diffraction intensity  scalar diffraction theory  pinhole size  defocus

目  次 

1 引言 1

1．1 研究背景及研究意义 1

1．2 国内外的研究现状及发展趋势 2

1．3 本文的主要研究内容 4

2 针孔衍射场光强分布的标量衍射理论研究 6

2．1 惠更斯一菲涅尔原理 6

2．2 基尔霍夫衍射定律 7

2．3 圆孔夫琅和费衍射定律 11

2．4 本章小结 13

3 衍射光强随针孔变化的数值计算 14

3．1 针孔尺寸对衍射场的光强影响 15

3．2 针孔横向离焦对衍射场的光强影响 17

3．3 针孔轴向离焦对衍射场的光强影响 19

3．4 本章小结 21

总结与展望 22