Application of Digital Image Correlation in Measuring Refraction Index of Transparent Material

Abstract

This article describes a method to measure the refraction index of transparent material by combining the characteristics of transparent material with 2D digital image correlation. The method established the relationship between refraction index and in-plane displacement of speckles using the refraction principle. In-plane displacement can be calculated by the 2D digital image correlation directly. Refractive index of PMMA were obtained by speckle patterns which were recorded by single camera. Results showed that the calculation is very close to the existing PMMA material refractive index value that proved the feasibility and the effectiveness of the method. Of course, this method also can be used to calculate the thickness of the transparent material to widen its using fields.