DERIVATIVES OF DISPLACEMENT OBTAINED BY DIRECT MANIPULATION OF PHASE-SHIFTED INTERFEROGRAMS

The maps of phase derivatives are extracted here by direct manipulatio n of phase-shifted interferograms. There are three main advantages: Th ere is no need for prior phase evaluation or unwrapping procedures, ac id only a short processing time is needed. By digital integration of t he derivatives the absolute phase map can also be retrieved without un wrapping procedures. A general description of the method is presented and discussed. For example, the proposed technique has been applied to the study of the deformation of a test object by the manipulation of four phase-shifted interferograms. (C) 1995 Optical Society of America .