Kenneth M. White

Processable Cross-Linked Polymers for Nonlinear Optical Applications

Novel difunctional barbituric acid methine dyes have been synthesized for nonlinear optical applications. These Molecules have been reacted with Multi-functional isocyanates resulting in cross-linked polyurethanes. The thermal stability of the dye in crystalline form as well as dissolved in poly (Methylmethacrylate) was studied. Results suggest that although the dye crystals were thermally stable to 300 °C, when dissolved in a polymer the stability was markedly lower.

Third Order Optical Nonlinearity in a Polymer Composite

Abstract : Third-order optical nonlinearity in organic materials has generally been sought from molecules and Polymers having extended 7c-electron delocalization in conjugated bonding schemes. In an alternative approach, we have investigated the third-order optical response of a polymeric composite containing charge transfer complexes in which the nonlinearity originates from intermolecular electron delocalization between pi-electron clouds in charge transfer stacks. The material, which is composed of a polymer having electron donating pendant side groups that complex with dopant electron-acceptor molecules, has been processed into an optically clear thin film. Nonlinear characterization of the film by means of third-harmonic generation suggests enhancement of the third-order response arising from charge transfer interactions.