Holographic interferometry with reference beams modulated by the object motion

Holographic interferometry with a reference beam reflected out of the object illumination beam by a small mirror fixed to the object compensates statistical vibrations and object motions caused by rough environments and yields stable interference patterns with sufficient contrast. Based on theoretical investigations of the fringe formation in this case, methods for determining the object motion and deformation are developed. It is shown that zero-order fringes always pass the reference mirror in the reconstructed holographic image when this method is used. The displacement of the reference mirror is determined by an additional object undergoing no motion between the two exposures of a double-exposure hologram.