Interferometric testing of the random phase object by focused spatially-modulated beam

A new measuring technique of statistical parameters of transparent or reflecting random phase objects is discussed. The technique is based on the usage of the probing spatially-modulated laser beam (beam with regular interference pattern), focused on a moving object, and on measurement of contrast of average intensity fringes, formed in scattered dynamic speckle-modulated field. The behavior of the speclde field interference induced by the focused spatially-modulated laser beam diffraction on the random phase objects has been studied. The dependence of dynamic field average intensity fringes contrast on the object parameters has been established. The divergencies of the illuminating beam and the scattered light were taken into account.