The subject of liquid crystals and their use in electronic displays and in non-linear optical systems has become of tremendous importance during the last decade; and the incorporation of liquid crystal units into polymeric materials has led to a group of new materials with diverse properties. Some of these properties have been utilized in new products and some have yet to be used. Much published work has appeared that deals with specific materials or particular applications, and it was felt that a book was needed to examine and explain the underlying principles governing the diverse properties of these liquid crystal polymers, LCPs. The current work describes the diverse nature of LCPs, their synthesis, characterization, properties and finally their applications. It describes the manner in which liquid crystallinity or mesomorphism occurs in small molecules, monomer liquid crystals and polymer liquid crystals. Chapter 1 gives a classification of the various ways in which the meso gens may be connected to the polymer chains. Currently, the bulk of LCP material is based on main chain or longitudinal LCPs for use in engineering applications. The side chain or comb polymers are intended for use in electronics and opto-electronic systems and as surfactants. Many other variants and possibilities exist but their properties have not yet been fully studied or used. In this respect it is hoped that the current work will indicate future possibilities as well as discussing current opinion. v Preface vi Chapters 2 and 3 describe methods of characterizing the mesophases.

Progress is reviewed on research into the design, synthesis and characterization of, primarily, side chain liquid crystalline polymers for nonlinear optics. Materials described are polyesters and vinyl polymers and copolymers having push-pull pi-electronic nlo structures as pendant groups. Chiral derivatives have also been prepared. The nlo species employed have been nitroaromatics and pyridine N-oxides. Results of collaborative efforts in further characterization (electrooptic, dielectric, Langmuir-Blodgett films) are described. Keywords: Nonlinear optical materials; Liquid crystals; Polymers. (mjm).

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.

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.