Interferometric comparison of displacements by electronic speckle pattern interferometry

Abstract

Using the image waves from two similar objects as, respectively, object wave and reference wave in an electronic speckle pattern interferometer (ESPI) setup, it is possible to obtain interference patterns that indicate the amount of relative displacement between the two objects. Experimental results demonstrating direct interferometric subtraction and addition of vibration patterns are presented. Possible applications of the technique are also discussed.