Extremely nonlinear photosensitive nematic liquid crystal film

Optically induced nematic liquid crystal (NLC) axis reorientations result i n extraordinarily large nonlinear refractive index changes. We discuss the origins of these nonlinearities, and recently, obtained results of experime ntal studies of photovoltage generation, dynamic grating diffraction, and i mage conversion using dye-doped NLC films in all-optical configurations are presented. These processes are characterized by unprecedented low threshol d laser powers. For example, we have demonstrated incoherent-coherent image conversion with laser intensity on the order of 70 microWatts/cm(2). (C) 2 000 Elsevier Science S.A. All rights reserved.