A REAL-TIME DIGITAL SHEARING SPECKLE INTERFEROMETER

Shearography is an interferometric method which measures surface displacement derivatives. Although useful for strain analysis and non-destructive testing, the conventional technique is cumbersome and not very suitable for an industrial environment. This paper presents the development of an electronic/digital technique which eliminates most of the shortcomings. In addition, it enables real-time shearographic fringes to be obtained.