Solidification behaviour of organic nonlinear optical crystals

A representative rather than exhaustive review has been given on the solidification behaviour of organic nonlinear optical crystals. Many of the developments reported here represent quick experimental responses to the rapid theoretical advances made in the field of nonlinear optics. The article is divided into four parts. The first part deals with the characteristics of the organic nonlinear materials and need for large single crystals. The second and third parts are devoted to the thermophysical properties and experimental studies on crystallization processes. Here, recent work by authors is reviewed on the purification of source material, solidification behaviour and crystal growth. Various interactions between morphology, microsegregation, defects, growth velocity and temperature gradient are discussed. Specific examples of substituted anilines are presented. In the fourth section a stronger interaction is suggested between optical physicists and crystal growers to understand the problems of inhomogeneity, stress, damage threshold and doping in the organic crystals.