by radially polarized light relocating said polarization rotator 14 from the vicinity of said pupillary plane 15 to a location closer to said wafer 11 will allow choosing a smaller diameter for said polarization rotator 14 while providing that at least some of those lenses l 12 u2013 l 16 situated between the indicated location of said polarization rotator 14 and said wafer 11 will still be irradiated by radially polarized light however the divergence i e the maximum angle of inclination with respect to said optical axis 16 of the beam incident on said polarization rotator 14 will then increase the ratio of the strength of said optical activity to that of said birefringence effects will decrease with increasing angle of incidence which will slightly worsen the effects due to said crystalline quartz material 39 s birefringence however decisions regarding the maximum angles of incidence that may be tolerated may be made based on the particular applications to be involved those decisions will also depend upon the extent to which light has been radially polarized with respect to the optical axis of the crystal of said polarization rotator 14 prior to its arrival at same since in the ideal case of.