Simultaneous Measurement of In-Plane and Out-of-Plane Displacements Using Talbot Fringe Projection

Abstract

The fringe projection technique has been widely used in optical measurements. In this paper, we demonstrate a scheme to measure the 3D displacement of a deformed sample using Talbot fringe projection. In this process, we designed a two-dimensional square Talbot hologram. In this approach, we used the basic principle of triangulation, and a computer-controlled liquid crystal spatial light modulator (LC-SLM) was placed in the optical path. The Talbot array hologram was displayed on the LC-SLM screen and projected onto the surface of a sample. Two patterns were recorded: one before and one after deformation. We simultaneously acquired the in-plane and out-of-plane displacements using the digital image correlation (DIC) method. This scheme is simple and easily implemented. Theoretical and experimental results are presented.