Materials design and physics of organic photorefractive systems

Photorefractivity is an intriguing phenomenon which, however, was initially perceived as a nuisance: Laser illumination generates large internal elect ric fields which, in turn, modify the optical properties of the material. U seful applications in holographic systems were soon recognized and photoref ractivity was subsequently demonstrated in many different materials. These materials span from inorganic crystals to semiconductors, from organic liqu id crystals to polymers. Nevertheless, nearly 25 years passed from the disc overy of inorganic photorefractive materials in 1966 to reports of the firs t organic systems. This article reviews the rapid progress of organic photo refractive materials in the last decade and focuses on the different chemic al concepts and pathways for: further optimization. Advanced systems are re quired to move photorefractivity out of research laboratories into the mark et.