Speckle Interferometry for Recording Microdisplacements and Deformations: An Overview of Methods

This article examines a class of speckle interferometry methods suitable for measuring mechanical and thermal deformation, flaw detection, structural damage monitoring, and vibration testing of large objects. It describes the historical development of speckle interferometry, from manual image processing to the most advanced methods capable of simultaneously determining all three directions of deformation. Several classification schemes for speckle interferometry have been proposed. Applications of the method in various industrial fields are analyzed. Various objects are considered, including industrial metal products, organic materials, composite materials, and others. Industrial solutions based on electronic speckle pattern interferometry are presented.