Frequency Doubling and Parametric Interactions in Organic Thin Films

Frequency doubling of lasers has attracted a lot of attention as a means of generating blue light in a compact source. This review summarizes efforts using organic crystals and polymers for frequency doubling, mainly in waveguides but also as free standing films. The theory of nonlinear parametric interactions in waveguides is presented. Different methods of phase matching in waveguides are also discussed. Then we review the molecules, polymers and crystals which are suitable for frequency doubling and discuss the tradeoff between transparency and nonlinear optical activity. Finally we review results obtained from waveguides by other workers in the field. We assess the status of the field in relation to other developing blue/green light sources.