Roughness measurement of oriented surface by depolarization of scattered light

In this work we present a study of light depolarization by an oriented rough surface. A polarized laser beam shines samples with different roughness in two different ranges and the intensity of depolarized light at normal direction is monitored. We show the applicability of Cross-Polarization Ratio (CPR) analysis, previously applied to random rough surfaces, for oriented rough surface. In addition, we observed a clear dependence of the depolarized light intensity by respect the sample's mean roughness (Ra) for both analyzed roughness range. Our results consist in a proof of principle for indirect roughness measurement of metallic samples and intend to be a potential application in industrial production line, once Ra can be related directly with an intensity measurement in a fast way.