title: Uniaxial crystal interferometer: principles and forecasted applications to imaging astrometry.
abstract: We propose a new approach to imaging astrometry, the uniaxial crystal interferometer (UCI). It uses the extremely sensitive dependence of the polarization phase change on the incident angle in uniaxial crystals. This is further combined with very sensitive polarization measurements. The polarization-coding is used for a fine-scale angle determination, and is simultaneously combined with a crude measurement through a standard telescope. Further, achromatic anamorphic prisms will amplify five to tenfold the resolution which is estimated to reach the scale ratio of large interferometers. Because the fine angular information is superimposed on the light at an early stage the optical system tolerances are relieved to the level of a standard low-weight optical imaging system. We also suggest solutions to make the system achromatic. Overall the system may cover sky segments of the order of fractions of a degree square and reach a resolution of tens of microas, even for faint stars.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Sirat
authors.forename: Kalman
authors.initials: K
authors.lastname: Wilner
authors.forename: Daniel
authors.initials: D
authors.lastname: Neuhauser