Sol−Gel Materials for Second-Order Nonlinear Optics

Sol−gel processing of new materials for second-order nonlinear optics promises to be a simple and highly versatile synthetic route among those that have been evaluated to achieve large and stable second-harmonic generation. Introduction to various types of organic chromophore−inorganic matrix hybrid materials that have been fabricated via sol−gel methodology and a survey of the recent efforts in optimizing their nonlinear optical efficiencies are presented. It is incurred that main-chain chromophore-embedded processable hybrids with high glass transition temperatures and thermal stabilites offer great potential in the quest for building a device based on second-order nonlinear optical efficiency of synthetic materials.