Page 11 - Photoreactive Organic Thin Films
P. 11
CONTENTS
10 Photoassisted Poling and Photoswitching of NLO Properties of
Spiropyrans and Other Photochromic Molecules in Polymers
and Crystals
JACQUES A. DELAIRE, ELENA ISHOW, AND KEITARO NAKATANI
10.1 Introduction 306
10.2 Molecular Second-Order Nonlinear Optical Polarizabilities of
Photochromic Molecules 307
20.2.1 Definitions 307
10.2.2 Methods of Determining Molecular Hyperpolarizabiliti.es:
Experiments and Calculations 308
10.2.3 Influence of Photochromism on Molecular
Hyperpolarizabilities 311
10.3 Photoassisted Poling of Photochromes Other Than Azo Derivatives in
Polymers 315
103.1 Principle 315
10.3.2 Measurement Techniques 317
10.3.3 Examples 318
10.3.4 Applications 320
10.4 Photoswitching of NLO Properties in Organized Systems and
Materials 321
10.4.1 Introduction 321
10.4.2 Photoswitching in Polymers 321
10.4.3 Photoswitching of NLO Properties of Noncentrosymmetric
Photochromic Crystals 322
10.4.4 Potential Applications 324
10.5 Conclusion 326
11 All Optical Poling in Polymers and Applications
ALEKSANDRAAPOSTOLUK, CELINE FIORINI-DEBUISSCHERT, AND
JEAN-MICHEL NUNZI
11.1 Standard Poling Techniques 332
11.1.1 Electric Field Poling (Corona Poling) 332
11.1.2 Photo-Assisted Electric Field Poling 333
11.2 All Optical Poling 334
11.2.1 Quasi-Permanent AII Optical Encoding of
Noncentrosymmetry 33 7
11.2.2 Relevant Parameters for an Efficient All Optical
Poling 340
2)
11.2.3 Characterization of the Photoinduced %* Susceptibility 347
11.2.4 Optimization of the Poling Efficiency 353
11.2.5 Perspectives 360