On a Method to Employ Newton’s Rings Concept to Determine Thickness of Thin Films

Abstract

Newton’s Rings experiment is traditionally utilized to find radius curvature of a lens. We propose a method in which this same set up can be used to find the thickness of thin films. The working principle is interference. It is based on the fact that, the formation of bright and dark interference fringes is a measure of the thickness of the air film at that point. We present the experimental data. The results from the experiment are in agreement with results obtained through geometry. Further, a method to improvise conventional interference at air wedge experiment which is generally used to determine the thickness of thin films is suggested.