We have prepared a hybrid organic-inorganic glass composite incorporating an aminosulfone dye via the sol-gel process. The dye was functionalized with alkoxysilane moieties to anchor it covalently into the silicate network. Co-condensation with the organically modified silicon alkoxide methyltrimethoxysilane (MTMS), gave transparent high-quality films that could be deposited up to 10 microns thick in one step. We discuss the structure and second-order nonlinear properties of these materials. For a poled and cured sample containing 0.5% (w/w) of the NLO dye, the magnitude of the electro-optic coefficient r13 is 2.2 plus or minus 0.4 pm/V.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.