Polarization aberrations caused by differential transmission and phase shift in high-numerical-aperture lenses:: theory, measurement, and rectification

We present a theoretical and experimental study of radially symmetric aberration caused by the differential transmission and phase shift of p- and s-polarized components of an axial beam passing through Marine Biological Laboratory spherical lenses and plane parallel plates. We give a general description of the aberrations for an axial beam. The extinction is calculated as a function of the numerical aperture for uncoated lenses and for plane parallel plates. In our theoretical analysis, the polarization of output rays is described as a function of the input ray parameters, the shape factor, and refractive index of the lenses used. For rays that are inclined to the optical axis, optimal lens shape factors that minimize the rays' polarization aberrations are found. Techniques for measurement of radially symmetric birefringence in a lens system are described. Finally, we discuss strategies for polarization rectification and introduce new designs including meniscus rectifiers and a liquid crystal rectifier that can actively compensate a wide variety of polarization aberrations. Good correlations between theory and experimental results for microscope optical systems with coated and uncoated optical elements are found. Our results enable us to suppress depolarization and remove anomalous diffraction in a modern microscope equipped with high-numerical-aperture lenses. (C) 2002 Society of Photo-Optical Instrumentation Engineers.