1ST-ORDER PHASE STATISTICS OF GAUSSIAN SPECKLES PRODUCED BY A CURVED SURFACE IN THE DIFFRACTION REGION

Statistical properties of the speckle phase produced in the diffractio n region by a curved rough surface are theoretically studied. The gene ral expression for the probability density function of the speckle pha se is derived by introducing an ''optical system function'' and taking the curvature radius of an object surface into the macroscopic phase component of the optical system function. The effects of the curvature radius of an object on the probability density function of the speckl e phase are investigated by using the equiprobability density ellipse from the viewpoint of circularity and the asymmetry of the complex amp litude of the speckle field.