OS01W0302 Fringe analysis by fourier transform phase-shifting method for four-beam moire interferometry

Abstract

A new technique of moire interferometry for simultaneous measurement of two-dimensional displacement components is proposed. The Fourier transform phase-shifting method is used for the analysis of the phase distributions of superposed fringes obtained from four-beam interference. In order to analyze a frequency component, the sampling number should be bigger than twice of the frequency. In this paper, we propose a new method for analyzing with less data sampling. A phenomenon called 'aliasing' in which the original frequency appears at a different frequency is used. Furthermore, the influence of the random noise upon the phase distributions with and without aliasing is inspected by a computer simulation. As an example for experiment, the thermal deformation of an electronic device is analyzed using the proposed method and the effectiveness of the proposed method is shown.