Sandwich hologram interferometry. 5: Measurement of in-plane displacement and compensation for rigid body motion.

Sandwich holography has been used for measurements of in-plane displacement of an object. The sign of the displacement is found by tilting the sandwich hologram during reconstruction. Fringes caused by inplane rigid body motion can be compensated for, and local displacements evaluated. It is shown that an inplane motion of more than 1 mm of the object placed at a distance of about 1 m from the plates can be compensated for and a local tilt of 1.5 x 10(-3) degrees evaluated. A comparision between conventional evaluation and evaluation of sandwich holograms by measuring the tilt angle of the plates to calculate an object's displacement is shown with a series of experiments.