Speckle size of digitally reconstructed wavefronts of diffusely scattering objects

A hologram of an object is recorded using a CCD-sensor and stored in a frame grabber. The hologram is reconstructed digitally using a computer by simulation of Fresnel diffraction. The complex amplitudes of the reconstructed wave fields and the coherence factor between two points in space is then calculated. The mean 3D speckle size in a digitally reconstructed wavefront is calculated by autocorrelation. By simulating ring apertures it is possible to reconstruct wavefronts containing speckle clusters.