In 1988 physicists and chemists commemorated the centenary of the discovery of the first liquid crystals. Fora long period after this discovery, although many significant results were found, liquid crystal research remained a marginal topic of condensed matter physics. The situation changed in the sixties. At that time the remarkable electro-optical properties of liquid crystals were recognized and found soon widespread application in numeric displays. From a more fundamental point of view, the interest in disordered systems. increased in general at the same time. Liquid crystals represented an important dass of such systems. Among others, phase transitions, hydrodynamics and topological defects occurring in them attracted considerable attention. The connection between the liquid-crystalline state and the structure of biological membranes stimulated a Iot of works also. In the present volume we discuss a relatively new and rapidly developing branch of the fi. eld, namely nonlinear optical effects in liquid crystals. Optical studies have always played a signifi. cant role in liquid crystal science. Research of optical nonlinearities in liquid crystals began at the end of the sixties. Since then it became a powerful tool in the investigation of symmetry properties, interfacial phenomena or dynamic behaviour. Furthermore, several new aspects of nonlinear processes were demonstrated and studied extensively in liquid crystals. The subject covered in this book is therefore of importance both for liquid crystal research and for nonlinear optics itself. The term "nonlinear optics" is used here in a broad sense.

This is a monograph/text devoted to a detailed treatment of the optical, electro-optical and nonlinear optical properties of all the mesophases of liquid crystals and related processes, phenomena and application principles. Quantitative data on material and optical parameters spanning the ultraviolet, visible, infrared as well as the microwave regimes are presented along with detailed theoretical treatments of basic liquid crystal physics, material properties and nonlinear optics.Starting with a discussion on the basic building blocks of liquid crystalline molecules, the authors proceed to present in a pedagogical manner current theories, experiments, and applications of these unique and important optical properties of liquid crystals. Numerous tables of hard-to-find liquid crystalline parameters, a self-contained chapter on general nonlinear optics, and comprehensive literature review are also included.

'Optical and Electro-Optical Properties of Liquid Crystals: Nematic and Smectic Phases' describes the general properties of the most popular liquid crystal (LC) phases nematics (Ns) and smectics (Ss), and in addition, is directed to fill in a niche of the LC field. This book covers topics ranging from the types and classifications of liquid crystals to a detail description of the fundamental properties of nematics and smectics, including continuum theory, non-linearity, behaviour in electric field, surface alignment, phase transitions, defect and textures and provides a useful reference intended for advanced topics of the physics of liquid crystals.

This monograph is devoted to a detailed treatment of the nonlinear optical properties of liquid crystals. The basic concepts of director optical reorientation and thermal nonlinearities are presented showing the fundamental theoretical approaches and describing the main experimental observations. The presentation is self-consistent and tutorial although the subject matter is of current research interest.The last part of the book deals with more recent results on new composite materials: Polymer Dispersed Liquid Crystals (PDLC). A general presentation of the optical properties is given and the observations of several nonlinear optical effects are reported.