光栅衍射演示实验中异常现象的分析

Theoretical analysis of abnormal phenomenon in diffraction-grating demonstration experiment

根据光栅衍射次波的迭加原理 ,分析光栅衍射演示实验中缺级现象时隐时现的原因 ,并得出结论 :要想消出实验中的异常现象 ,就必须使光栅既直观又精密 ,即 :使光栅在直观的前提下 ,每条刻痕宽度相等 。

According to the superposition principle of light sub wave passing through a diffraction grate, we have analyzed why order absent phenomenon displays now and than in the diffraction grating spectrum. It is concluded that in order to remove this kind of abnormal phenomenon, not only the width of the grooves must be uniform, but also the ratio between diffraction grate constant and slit width must be an integer.