Holographic interferometry with increased sensitivity for diffusely reflecting objects.

The reconstructed image of a double exposure hologram, made by deforming the object and slightly tilting the signal beam at the same time, consists of modulated Young's fringes. It would be possible to presume the plate, which is used for taking a photograph of the reconstructed image and is processed in a nonlinear way, to be equivalent to a nonlinear hologram. Therefore the principle of phase difference amplification applies. Thus the interferogram with increased sensitivity of lambda/16 per fringe was experimentally obtained with a diffusely reflecting object. Discussions of the system error are presented.