Light-scattering Speckle Patterns and Their Correlation Properties

Abstract Spatial speckle patterns formed by the scattering of plane-polarized monochromatic light normally incident on polymer films of various structures are presented for both polarized and unpolarized light intensities. Depolarization caused by the scattering medium leads to both parallel and cross-polarized electric-field components in the scattered field. A statistical analysis based on the measurement of the probability density function of addition of two correlated speckle patterns provides the degree of correlation between contributions. Specifically, the degree of correlation can be obtained by fitting the experimental data to the theoretical probability density function, the form of which has been derived. An analysis of speckle-pattern correlation as measured by digital subtraction of clipped speckle patterns at different polarization-plane orientations shows consistent results. The determination of the coherence factor may be useful for studying optically heterogeneous media that change the po...