Measurement of 3-D Shape and Refractive Index of a Transparent Object using Laser Rangefinder

In this paper, we propose a method of measuring 3D shape and refractive index of a transparent object using a triangulation-based rangefinder. The rangefinder is based on the fact that the light projected onto the surface of a transparent object is partly reflected by the surface, though the majority of the projected light is transmitted through the surface. The measuring principle is to detect the reflected light and the transmitted light from a transparent object, and to apply our proposed triangulation to these lights. We built a prototype rangefinder and confirmed the efficacy of this method. As a result, we conclude that the proposed approach has great potential for a wide range of industrial applications