In this contribution we experimentally investigate backscattering and polarization rotation induced by sidewall roughness in silicon-on-insulator (SOI) optical waveguides. Waveguides with different widths, different upper cladding and longitudinally tapered have been measured and compared. All the measurements have been performed by means of an advanced frequency domain interferometric technique, which allows the evaluation of both amplitude and phase of backscatter as well as its polarization
