Abstract
Recently we constructed universal crystal polarimeter called HAUP, by which we can measure birefringence, optical activity, rotation of the indicatrix, and electrooptic and electrogyration coefficients simultaneously. HAUP was successfully applied to measure optical activity of TGS, (NH4)2BeF4, K2SeO4, Rb2ZnCl4 and PbTiO3. This paper deals with the utility of optical activity and electrogyration effect for the study of ferroelectrics by taking these crystals as examples.