Measuring optical beam shear angle of polarizing prisms beyond the diffraction limit with localization method

Abstract We demonstrate a simple and direct method to precisely characterize the optical beam shear angle of polarizing prisms. Applying nanometer localization analysis for determining the central positions of the two sheared spots with orthogonal polarizations, we show that it allows for resolving the shear angle beyond the optical diffraction limit. We use Nomarski prisms to verify our technique and obtain a resolution below 0.5 μ rad. Our method provides a stand-alone characterization of polarizing prisms with a high accuracy for many quantitative imaging technologies such as differential interference contrast microscopy.