Development of HAUP and its applications to various kinds of solids

Optical activity was found in 1811 by Arago. However, optical activity of solids is extremely small and overwhelmed by existing birefringence, so it could not be measured until the high accuracy universal polarimeter (HAUP) was developed by us in 1983. The HAUP method enables us to measure optical activity and birefringence of any solids even belonging to monoclinic and triclinic systems. The principles of the HAUP and the more generalized one are given. The applications of the HAUP method to various kind of solids, i.e., the elucidation of the origin of the incommensurate state of ferroelectrics, optical activities of monoclinic crystals, huge optical activity of high polymer sheet, and the first measurement of a protein, lysozyme, crystal are described. These applications illustrate that axial tensorial consideration provides otherwise inaccessible insight of previously unsolved problems. Therefore we stress the necessity of developing a new research field defined as 'chiral physics', where axial tensors play essential roles.