Construction and operation of a simple electronic speckle pattern interferometer and its use in measuring microscopic deformations

摘要

The construction and operation of a simple electronic speckle pattern interferometer (ESPI) is described. The underlying theory behind the operation of the interferometer, which is sensitive to out-of-plane displacements, is given. The interferometer uses a commercial digital still camera for image acquisition and a personal computer for image storage and analysis. The interferometer was used to measure microscopic deformations of a steel plate caused by small loads. The results were found to be in good agreement with the predictions of the elastic theory. Various possible applications of the interferometer are mentioned. (C) 2000 Elsevier Science Ltd. All rights reserved. [References: 16]