掠射法测液体折射率实验中的几个问题

SEVERAL PROBLEMS OF MEASURING LIQUID REFRACTIVITY BY GRAZING METHOD

掠射法测液体折射率是根据光的全反射原理。以往对测试公式的推导大都从临界光线出发,这祥处理掩盖了临界光线光能量传播的实质。本文用极限的方法给以推导,使其与半阴区出现的物理过程相一致。对实验现象的分析,有利于全面理解实验中所涉及的光学知识,尤其是深入理解实验中所出现的干涉条纹,有助于准确、迅速地确定半阴区的方位,同时也提供了一个观察薄膜透射光干涉的简易方法。

The measurement of liquid refractive index by grazing met- hod is based upon the principle of total reflection.In the past the deduced formula was mostly derived from critical rays.To process in this way,the essence of energy propagation of critic- al rays was not revealed.The author offers an alterative deduc- tion method by taking limit to get the formula so as to meet the physical process of occurring half shade.This eases to fully understand the knowledge concerning optics,especially the inte- rference fringes that occur in experiment & is helpful to deter- mine the half shade orientation rapidly & accurately.It also su- ggests a simple method to observe the interference of light when penetrating through film.