The use of liquid crystal adaptive optics devices in astronomy

Abstract

Images obtained from large astronomical telescopes are distorted and blurred by the effects of the atmosphere. In order to compensate for this, an adaptive optics system can be incorporated downstream from the telescope focus. Conventional technology uses small piezo-driven mirrors to deviate the wavefronts through angles of the order of tens of arcseconds. This thesis is concerned with the possible replacement of these mirrors with liquid crystal phase control devices, in particular, small-angle prisms. The thesis considers the following fundamental optical properties of liquid crystals relevant to astronomy; dispersion, optical quality, dynamic range, and response times. Results of a novel approach to electrically addressing liquid crystals by a ramp voltage are given.