EFFECT OF MULTIPLE-SCATTERING ON THE INTENSITY FLUCTUATION OF SPECKLE BACKSCATTERED FROM A RANDOMLY ROUGH METAL-SURFACE

In laser speckle backscattered to the far field from a randomly rough metal surface the effect of multiple scattering on the intensity fluctuation g(2)(0) is investigated. The s-polarized (perpendicular to the incidence plane) laser beam is incident with an angle of −30° on the slowly rotating ground glass. The ground surface is aluminum coated, and the angular distributions of the mean intensity and the g(2)(0) of the dynamic speckle are measured. The results show that depolarization is significant in the mean intensity, and g(2)(0) is found to be less than 2 in the Gaussian scattering region. The relation between the depolarization and g(2)(0) is derived theoretically and verified experimentally. © 1990 Optical Society of America.