Photoalignment of Liquid Crystalline Materials

Vladimir G. Chigrinov obtained his PhD degree in solid-state physics from the Shubnikov Institute of Crystallography, USSR Academy of Sciences, in 1978. In 1988, he defended his doctoral degree and became a professor at the Shubnikov Institute of Crystallography, where he was a leading researcher from 1996. He joined HKUST in 1999 and is currently an associate professor. Since 1974 Professor Chigrinov has published 2 books. 15 reviews and book chapters, about 150 journal papers, more than 300 conference presentations, and holds more than 50 patents and patent applications in the field of liquid crystals. He is a Senior SID Member, SID Fellow and an Associate Editor of the Journal of the Society for Information Display. Vladimir M. Kozenkov graduated from the Moscow Energetic Institute as a scientist in applied physical optics (laser department). For 30 years he worked at the Organic Intermediates and Dyes Institute (NIOPIK) in Moscow. He pioneered research and development of various organic photosensitive materials for holography, waveguide, integral and polarization optics, stereolithography, optical memory, imaging processing, and security applications. He was the first to discover the phenomenon of photoinduced birefringence in polyvinyl-cinnamate films in 1977. He has published more than 100 refereed papers and holds more than 50 patents.Hoi-Sing Kwok obtained his PhD degree in applied physics from Harvard University in 1978. He joined the State University of New York at Buffalo in 1980 and became a full professor in 1985. He joined HKUST in 1992 an is currently Director of the Center for Display Research (www.cdr.ust.hk). Professor Kwok has written over 500 refereed publications and holds 40 patents in laser optics and LCD technologies. He is a Fellow of the OSA, the IEEE, and the SID.

"I believe that the reader will obtain beneficial information on the various aspects of the physics and applications of the photoalignment of LCs and the techniques involved." (Liquid Crystals Today, June 2010)

• About the Authors. Series Editor's Foreword.1. Introduction.References.2. Mechanisms of LC Photoalignment.2.1 Cis-Trans Isomerization.2.2  Pure Reorientation of the Azo-Dye Chromophore Molecules or Azo-Dye Molecular Solvates.2.3 Crosslinking in Cinnamoyl Side-Chain Polymers.2.4 Photodegradation in Polymide Materials.2.5 Photoinduced Order in Langmuir–Blodgett Films.References.3. LC-Surface Interaction in a Photoaligned Cell.3.1 Pretilt Angle Generation in Photoaligning Materials.3.2 Generation of Large Pretilt Angles.3.3 Anchoring Energy in Photoaligning Materials.3.4 Stability of Photoaligning Materials Sensitivity to UV Light.3.5 Comparison of the Characteristics of Photoalignment Layers for Different Mechanisms of LC Photoalignment.3.6 Various Methods for the Experimental Characterization of Photoalignment Layers.References.4. Photoalignment of LCs.4.1 Vertical LC Alignment.4.2 Twisted LC Photoalignment.4.3 Photoalignment of Ferroelectric LC.4.4 Optical Rewritable LC Alignment.4.5 Photoalignment with Asymmetric Surface Anchoring.4.6 LC Photoalignment on Plastic Substrates.4.7 Photoalignment on Grating Surface.4.8 Photoalignment of Lyotropic and Discotic LCs.4.9 Other Types of LC Photoalignment.References.5. Application of Photoalignment Materials in Optical Elements.5.1 Polarizers.5.2 Retardation Films.5.3 Transflective LCD with Photo-Patterned Polarizers and Phase Retarders.5.4 Security Applications of Photoaligning and Photo-Patterning.5.5 Optical Elements Based on Photoaligning Technology.References.6. Novel LCDs Based on Photoalignment.6.1 Bistable Nematic Displays.6.2 Photoaligned Liquid-Crystal-on-Silicon Microdisplays.6.3 Photoaligned Ferroelectric LCDs.6.4 New Optical Rewritable Electronic Paper.6.5 Application of Photoalignment in Photonic LC Devices.References.7. US Patents Related to Photoalignment of Liquid Crystals.7.1 Introductory Remarks.7.2 List of Patents Patent Classification.7.3 Analysis and Comments on the Patents.Index.