MEASUREMENTS OF LIGHT-SCATTERING BY A SERIES OF CONDUCTING SURFACES WITH ONE-DIMENSIONAL ROUGHNESS

Measurements of the polarization dependence of the coherent and diffuse scatter from a set of seven conducting surfaces with strictly one-dimensional roughness are presented. The surfaces have been fabricated in gold with photoresist techniques and have been accurately characterized with stylus profilometry. The standard deviation of surface height sigma varies between 0.25 and 1.73 mu m throughout the series of surfaces, but all have height statistics that are close to Gaussian and a correlation length that is nearly fixed at 3.3 mu m. The polarization dependence of the scattered intensity is fully specified by the four unique elements of the Stokes matrix, which are determined from six intensities measured with different polarization conditions. In studies of the coherent scatter for wavelength 3.392 mu m, large differences are found between the p- and s-polarized intensities, and it is shown that the relative phase of the p and s coherent amplitudes is strongly dependent on sigma. In the case of diffuse scatter, the wide range of behavior exhibited by the scattered intensities and matrix elements is demonstrated for wavelengths 1.152 and 3.392 mu m. The rise of backscattering enhancement and associated polarization effects are seen as sigma increases, and it is shown that surfaces with surprisingly modest slopes may produce backscattering enhancement. At high angles of incidence, large differences between the p- and s-polarized diffuse intensities are observed.