Polarization characteristics of diffraction scattering from metal rough surface

For macroscopically rough surface with roughness much greater than wavelength of probe light, scatter from the surface can be explained to some extent as the specular reflection by the local facet. When surfaces possess gratinglike one dimensional patterns diffraction is also the reason of scatter. In this paper, we have characterized the polarization signature of the diffraction scattering by measuring Stokes parameters and polarization degree of scattered light by four samples with different surface patterns and roughness. Through comparison of polarization signatures of scattering from arbitrary and gratinglike one dimensional surface, it was found that the diffraction does not significantly affect the change of polarization state of scattering. The facet model is still available to some extent for polarization behavior of diffraction scatter by macroscopic rough surface.