Liquid Crystals

IAM-CHOON KHOO, PhD, is the William E. Leonhard Professor of Electrical Engineering at Pennsylvania State University, USA. He is a Life Fellow of the Institute of Electrical and Electronics Engineers (IEEE), and a Fellow of the Optical Society of America, UK Institute of Physics and The Electromagnetic Academy.

"Khoo's book is an exceptional resource that comprehensively explores the fascinating world of its namesake. As with previous editions, this meticulously updated and expanded edition delves deep into both fundamental principles and the myriad applications of these unique materials, making it a useful text for students, researchers, and engineers in the field. This third edition brings the book up to date with the latest advancements in liquid crystal research. New topics for this edition includes photonic crystals, metamaterials, ultrafast nonlinear optics, and fabrication techniques for cholesteric and blue-phase liquid crystals."—Ryan Aguinaldo, IEEE Photonics Newsroom Book Reviews Editor

• Preface xiiiChapter 1. Introduction to Liquid Crystals 11.1. Molecular Structures and Chemical Compositions 11.2. Optical Properties 31.3. Lyotropic, Polymeric, and Thermotropic Liquid Crystals 61.4. Mixtures, Polymer-dispersed, and Dye-doped Liquid Crystals 111.5. Liquid Crystal Cells Fabrication 16Chapter 2. Order Parameter, Phase Transition, and Free Energies 292.1. Basic Concepts 292.2. Molecular Interactions and Phase Transitions 332.3. Molecular Theories and Results for the Liquid Crystalline Phase 342.4. Isotropic Phase of Liquid Crystals 39Chapter 3. Nematic Liquid Crystals 443.1. Introduction 443.2. Elastic Continuum Theory 443.3. Dielectric Constants and Refractive Indices 493.4. Optical Dielectric Constants and Refractive Indices 533.5. Flows and Hydrodynamics 603.6. Field-induced Director Axis Reorientation Effects 67Chapter 4. Cholesteric, Smectic, and Ferroelectric Liquid Crystals 734.1. Cholesteric Liquid Crystals 734.2. Optical Properties of Cholesterics 794.3. Cholesteric Blue Phase Liquid Crystals 974.4. Smectic and Ferroelectric Liquid Crystals: A Brief Survey 100Chapter 5. Light Scattering 1155.1. Introduction 1155.2. Electromagnetic Formalism of Light Scattering in Liquid Crystals 1155.3. Scattering From Director Axis Fluctuations in Nematic Liquid Crystals 1185.4. Light Scattering in the Isotropic Phase of Liquid Crystals 1225.5. Temperature, Wavelength, and Cell Geometry Effects on Scattering 1255.6. Spectrum of Light and Orientation Fluctuation Dynamics 1275.7. Raman Scatterings 1295.8. Brillouin and Rayleigh Scatterings 1335.9. A Brief Introduction to Nonlinear Light Scattering 138Chapter 6. Liquid Crystals Optics and Electro-optics 1426.1. Introduction 1426.2. Review of Electro-Optics of Anisotropic and Birefringent Crystals 1436.3. Electro-Optics of Nematic Liquid Crystals 1496.4. Nematic Liquid Crystal Switches for Display Application 1566.5. Electro-Optical Effects in Other Phases of Liquid Crystals 1596.6. Non-Display Applications of Liquid Crystals 163Chapter 7. Optical Propagation in Anisotropic Materials 1757.1. Electromagnetic Formalisms for Optical Propagation 1757.2. Polarized Light Propagation in Liquid Crystal Display Panel 1857.3. Extended Jones Matrix Method 1937.4. Finite-difference Time-domain technique 1967.5. Nonlinear Light Propagation in Liquid Crystals – a First Look 1977.6. Systems of Units 198Chapter 8. Laser-induced Reorientation Nonlinear Optical Effects 2038.1. Introduction 2038.2. Laser-Induced Molecular Reorientations in the Isotropic Phase 2048.3. Molecular Reorientations in the Nematic Phase 2128.4. Nematic Phase Reorientation Dynamics 2198.5. Laser-Induced Director Axis Realignment in Dye-Doped Liquid Crystals 2258.6. DC Field Aided Optically Induced Nonlinear Optical Effects in Liquid Crystals – Photorefractivity 2268.7. Reorientation in Other Phases of Pristine (Undoped) Liquid Crystals 234Chapter 9. Thermal, Density, Lattice Distortion Optical Nonlinearities in Nematic, Cholesteric, and Blue-phase Liquid Crystals 2419.1. Introduction 2419.2. Electrostriction and Flows in Non-Absorbing Liquid Crystals –a General Overview 2429.3. Laser-Induced Density and Temperature Modulations in Liquid Crystals 2459.4. Optical Nonlinearities of Nematic Liquid Crystals 2549.5. Coupled Nonlinear Optical Effects in Nematic Liquid Crystals 2609.6. Nonlinear Optical Responses of Cholesteric Blue-Phase Liquid Crystals 266Chapter 10. Electronic Optical Nonlinearities 27510.1. Introduction to Quantum Mechanical Treatment of Molecules 27510.2. Density Matrix Formalism for Optical Induced Molecular Electronic Polarizabilities 27810.3. Linear and Nonlinear Electronic Susceptibilities 28210.4. Intensity-Dependent Refractive Index Change and nonlinear Absorption 296Chapter 11. Nonlinear Optics 30211.1. Introduction 30211.2. Coupled Maxwell Wave Equations 30811.3. Nonlinear Optical Phenomena 31011.4. Stimulated Scatterings 32811.5. Ultrafast Laser Pulse Self-Action Effects in Cholesteric Liquid Crystals 342Chapter 12. Nonlinear Optical Processes Observed in Liquid Crystals 34812.1. Self-Action Nonlinear Optical Processes 34812.2. Optical Wave Mixings 35812.3. Liquid Crystals for All-Optical Image Processing 36912.4. Harmonic Generations and Sum-Frequency Spectroscopy 37412.5. Optical Switching 37512.6. Nonlinear Absorption and Optical Limiting of Lasers for Eye/Sensor Protection 379References 390Index 398