从近场衍射到夫琅禾费衍射过程中的光场重构  

RECONSTRUCTION OF OPTICAL FIELDS IN THE PROCESS OF NEAR-FIELD DIFFRACTION TO FRAUNHOFER DIFFRACTION

作　　者：梁果 陈向炜 LIANG Guo;CHEN Xiangwei(School of Electrical&Electronic Engineering,Shangqiu Normal University,Shangqiu,Henan 476000)

机构地区：[1]商丘师范学院电子电气工程学院,河南商丘476000

出　　处：《物理与工程》2024年第5期99-102,共4页Physics and Engineering

基　　金：国家自然科学基金(11604199);教育教学改革研究与实践项目(2021jgybxm15);基础教育课程改革课题研究项目(2022-JC-15);河南省高等学校青年骨干教师培养计划;河南省高等教育教学改革研究与实践项目(2023SJGLX087Y)。

摘　　要：夫琅禾费衍射是光学中的一个重要的物理概念,其中单缝、方孔、圆孔的夫琅禾费衍射光场结构已为大家所熟知。本文讨论光束在近场衍射到夫琅禾费衍射(远场衍射)过程中的光场重构现象。本文发现在一维和二维光场重构过程中,光强分布会变化,光场能量会重新分布;特别地,发现平面波经过二维孔(方孔和圆孔)后,光场会产生自动聚焦现象。以椭圆光场和像散椭圆光场为例,本文讨论了在二维光场在重构过程中的光斑形变和旋转现象。在实验上,夫琅禾费衍射可以由凸透镜实现。Fraunhofer diffraction is one of the important physical concepts in optics,where the diffraction patterns of single slits,square apertures,and circular apertures in Fresnel diffraction are well known.In this paper,we discuss the phenomenon of light field reconstruction of optical fields in the process of near-field diffraction transiting to Fraunhofer diffraction(farfield diffraction).It is found that the intensity structure will change and the optical energy will redistribute in the reconstruction of one-dimensional and two-dimensional optical fields.Especially,the a autofocusing effect of the light field is found when a plane wave passes through a two-dimensional aperture(square hole and circular hole).Taking elliptical light fields and astigmatic elliptical light fields as examples,we discuss the deformation and rotation of light spots in the reconstruction process of two-dimensional light fields.Experimentally,Fraunhofer diffraction can be achieved by a convex lens.

关 键 词：夫琅禾费衍射 菲涅尔衍射 傅里叶光学 

分 类 号：O436.1[机械工程—光学工程]