杨氏双缝干涉实验中双缝缝宽的讨论

Discussion of the Width of Slits in Young’s Double-Slit Interference Experiment

首先基于惠更斯菲涅尔原理,推导了双缝具有一定宽度时的双缝干涉光强表达式。根据该解析表达式,利用数学软件进行数值模拟,结果发现:当双缝具有一定宽度时,双缝干涉条纹不再是理想的等亮度等间距的干涉条纹,而是从中间往外光强将逐渐衰减,并且在一定的双缝间距和缝宽比值时,还会出现条纹消失的现象。对于这些理论模拟结果,给予了相应的解释。此外,还进行了相应的实验观测,实验结果和理论结果基本一致。本论文所讨论的内容,对于进一步完善和深入讨论杨氏双缝干涉实验的教学和实验内容具有一定的指导意义。

Based on the Huygens-Fresnel principle,the intensity distribution expression of double-slit interference with the consideration of slits width is derived.According to the expression,the theoretical results are simulated.It is found that,if the width of the slits cannot be neglected,the interference fringes is not the ideal fringes with same intensity and spacing,but the intensity magnitude decreases with the radial distance increases from center.Moreover,if the distance between two slits is integral multiple of the width of each slit,the fringe may disappear.The explanation of the theoretical results is presented.In addition,the experiment is carried out,and experimental observation is consistent with the theoretical simulation.It is a meaningful discussion for further understanding the teaching and experiment of double-slit interference experiment.