Principles and applications of optical crystals; their stoichiometry study

Abstract

All optical crystals are classified into two kinds: isotropic crystals and anisotropic crystals. Optical crystals, which have a transparent range from the near-ultraviolet to infrared regions, are very attractive for diverse optical devices. To understand the optical functions of optical crystals, one can consider the behavior of a light wave in a crystal. The crystal gives a medium where the light wave interacts with external signals. Light propagation is affected by the crystallinity and optical in-homogeneities associated with compositional fluctuations. Understanding the phase diagram of a compound to be grown in single crystalline form is very important. This chapter describes the way in which the phase relations of electro-optic LiTaO3 and Bi12TiO20 single crystals are established so as to grow them with high optical homogeneity. For the growth of optical crystals, deep insight of the stoichiometry is a very important issue, and establishing the congruent composition is crucial for obtaining reproducible optical quality for most binary compounds.