ANGULAR-DEPENDENCE AND POLARIZATION OF OUT-OF-PLANE OPTICAL-SCATTERING FROM PARTICULATE CONTAMINATION, SUBSURFACE DEFECTS, AND SURFACE MICROROUGHNESS

The angular dependence and the polarization of light scattered by a sm all particle a distance d inside and outside a reflecting surface is c alculated in the Rayleigh limit. This calculation yields expressions f or the polarized bidirectional reflectance distribution function matri ces for in-plane and out-of-plane scattering. The results are compared with those obtained from microroughness-induced scattering. For the p -in/p-out configuration with oblique incidence, there exist out-of-pla ne angles for which scattering that is due to one of the mechanisms va nishes, whereas that from the others does not. By exploiting this know ledge, me can make improvements in the detection of small particles or subsurface defects. It is also shown that one must take care when dif ferentiating subsurface-defect-induced scattering from microroughness- induced scattering using in-plane scattering and wavelength scaling la ws.