Precise characterization of polarizing prisms by optical localization analysis.

We utilize the localization analysis method to precisely determine the light beam positions with the spatial separation beyond the optical diffraction limit. By such a direct spatial measurement, the associated optical setup is built to characterize the beam-shear angle of polarizing prisms that refract the light propagation according to polarization. We use the Nomarski prisms to demonstrate our method. The statistical error is below 0.5 urad, which is two orders of magnitudes smaller than the tolerance value given by most prism manufacturers. Our method provides a stand-alone characterization of prisms with a high accuracy for many quantitative imaging technologies such as the orientation-free DIC microscope and the dual-focus fluorescence correlation spectroscopy.