Statistics of Dynamic Speckles Produced by a Moving Diffuser under the Gaussian Beam Laser Illumination

Abstract

Statistical behaviors of temporally fluctuating speckles produced by a moving diffuser are studied in connection with the statistical parameters of the rough surface. In the time domain, the second-order correlation of the light amplitude in the diffraction field is calculated in a general form and, then, applied for the gaussian beam illumination. The intensity correlation is also investigated by assuming that the amplitude variation of the diffraction field follows a gaussian random process. The results analyzed theoretically and confirmed experimentally show that the averaged intensity strongly depends on the surface roughness and that the correlation length of intensity fluctuations in a temporal sense is independent of it.