Deformation measurements of specular reflecting objects using holographic interferometry with diffuse illumination

We demonstrate that by using diffuse object illumination, deformation measurements with hologrpahic interferometry can be performed on a specularly reflecting object without the use of any additional coating of the object surface. An expression for the secondary fringe formation is found, and the system is found only to be sensitive to deformations along the surface. The fringe visibility is studied for a rigid rotation of the object by using the theory of speckle decorrelation. It is found that maximum fringe visibility is obtained if the recording camera is focused on the surface of the object. Agreement between the theory and the experimental results are found.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.