Measuring polarization profile along an input optical beam cross-section using an optical system includes a polarization beam splitting assembly for splitting the input beam into a predetermined number of beam components with a predetermined polarization relation between them, and including a polarization beam splitter in an optical path of the input beam splitting it into beam components having a polarization relationship and a birefringent element in an optical path of the beam components for splitting each of them into a pair of beams having ordinary and extraordinary polarizations, thereby producing the predetermined number of output beam components. The pixel matrix is located in substantially non-intersecting optical paths of the output beam components and generates a number of output data pieces indicative of intensity distribution within the output beam components and data contained therein being indicative of the polarization profile along the input beam cross-section.