OS01W0435 A unified approach for holography and shearography in surface deformation measurement and nondestructive testing

Abstract

This paper views digital holography and digital shearography and their variations as a single optical technique having the same basic mathematical formulation and instrumentation. A key optical component used in both techniques is a doubly-refractive prism that combines two angularly separated laser rays to interfere at near collinearity, thereby producing interference patterns of very low spatial frequency that is resolvable by CCD cameras.