狭缝宽度对双缝后光场分布的影响  

THE INFLUENCE OF SLIT WIDTH ON LIGHT SUPERPOSITION THROUGH DOUBLE-SLIT STUDIED BY MATLAB

作　　者：刘长菊[1] 丁豹 谭玉彬 苏未安[1] LIU Changeju;DING Bao;TAN Yubin;SU Weian(School of Science,Jiangxi University of Science and Technology,Ganzhou Jiangxi 341000)

机构地区：[1]江西理工大学理学院,江西赣州341000

出　　处：《物理与工程》2018年第6期100-106,共7页Physics and Engineering

基　　金：江西理工大学校级大学生创新创业训练计划项目(XZG-15-08-35);江西省高等学校教学改革研究省级课题(JXJG-17-7-21)

摘　　要：双缝光叠加的内容是波动光学中的重要组成部分,其后场是单缝菲涅耳衍射与双缝干涉综合作用的结果,难以得到精确的解析表达。本文基于波动光学中的惠更斯-菲涅耳原理,通过Matlab数值计算获得了不同双缝之后的光场分布。结果表明狭缝的宽度对其后叠加光场分布的影响很大。对于不透光部分为5.0mm的等宽双缝,当缝宽与入射光波长数量级相同时,其后轴线附近的光场可近似为杨氏双缝干涉结果;当缝宽比入射光波长大1～2个数量级时,其后场可近似为单缝夫琅禾费衍射修正的杨氏双缝干涉结果;而当缝宽比入射光波长大3个数量级以上时,后场表现为明显的直线传播特性。只有在宽度适当的双缝之后才出现典型的光栅衍射图谱,而且两缝宽度之间的差异将使得反衬度γ降低,导致条纹模糊。The light superposition of double-slit,as an important part of wave optics,is the result of single slit diffraction and double slit interference effect.And the accurate analytical results is very difficult to obtain.Based on the Huygens Fresnel principle,the distribution of superposition light field behind different double slits is simulated by using Matlab.And found that the width of the slits has a great influence on the light distribution behind double-slits.As the non-translucent part between the equal width of 5.0 mm double slits,the paraxial light distribution can be approximated as Young’s interference and Young’s interference corrected by single-slit diffraction when the slit width greater than the wavelength.A typical grating diffraction pattern occurs only after the proper width of double sl and the wavelength are the same order and large 1~2 orders of magnitude.However,it exhibits a significant linear propagation characteristic when the slit width is three or more orders of magnitude greater than the wavelength.A typical grating diffraction pattern occurs only after the proper width of doubleslit,and the difference between the two slits width will result in a reduction in the contrastγ,resulting in blurring.

关 键 词：惠更斯-菲涅耳原理 双缝叠加 杨氏双缝干涉 单缝衍射 Matlab计算模拟 

分 类 号：O436[机械工程—光学工程]