Fringe loci and visibility in holographic interferometry with diffuse objects. II - Fringes of equal thickness
We investigate the three-dimensional distributions of loci and visibility of the fringes observed in the image region of a diffuse object in double-exposure holographic interferometry. The loci are shown to represent the contour lines of surface displacement in a certain direction and have the local spatial frequency proportional to the amounts of rotation and strain of the object, while the visibility is a function of the ratio of the amount of the speckle movement caused by the object deformation to the mean speckle size, depending on aperture size. The results of the computer calculation based on the analytical relations are graphically exhibited for typical cases.