Imaging using fourth-order correlations of coherent fields

摘要

Abstract: Correlations of coherent backscatter intensities have been used to form Fourier spectra of coherently illuminated objects. Both second and some fourth-order correlations have been studied. We add to this by describing a new method using fourth order field correlations for imaging. If one knows the actual object speckle field, or certain sheared versions of it, then it is possible through fourth-order correlations to obtain the incoherent brightness function of the object. The technique will allow simultaneous averaging-out of both field phase distortions, certain field measurement noises, and laser speckle.!9