Liquid crystals at the turn of the century

This paper briefly presents the history of the discovery and study of lyotr opic and thermotropic liquid crystals (LCs), the development of the theory of the mesomorphic state of matter, and the main electrooptic effects in LC s, which determine the area in which they are put to practical use. The pap er discusses the main display and nondisplay applications of thermotropic L Cs, which have imparted a new and powerful impulse to the development Of op tical instrumentation. (C) 2001 The Optical Society of America.