We apply finite-difference time-domain simulation, a numerical tool coming from electrical engineering, for studying the polarization optical response of rough surfaces. It is shown that the method can be used to calculate the polarization dependent reflectivity and the phase jumps for s and p polarization at a sample surface with arbitrary surface structure, even if the dimensions of the corrugation are close to the optical wavelength. The reflectivity for s and p polarization and their phase shift is calculated for a dielectric model structure as well as for a transistor model structure consisting of multiple stratified layers including metallization pads. Furthermore, the relative intensities and phase shift for diffracted beams are investigated and the sensitivity of the optical response on variation of parameters is discussed. (C) 2004 Elsevier B.V. All rights reserved.