Computer-aided interferometer for testing microdisplacement of piezoelectric ceramics

This paper proposes a kind of computer-aided contact-type interferometer for testing the microdisplacement of piezoelectric ceramics (PZT). Its accuracy is better than 0.01 mu m. A data acquisition system, including a CCD, grabber, etc., has been used to detect and digitize interferograms. This system analyzes a two-dimensional interferogram automatically and quickly, while both calibrate with monochromatic fringes and test with achromatic fringes. Software has been used to analyze the two-dimensional interferogram and to rest the nonlinearity and hysteresis of PZT. (C) 1999 John Wiley & Sons, Inc.