Trimethoxysilane and water were reacted directly, at 25-70-degrees-C, using substoichiometric water-to-siloxane ratios. Following partial polymerization and distilling-out of the produced methanol, carried out under inert atmosphere, the viscous polymer formed within a few minutes and could be spin-cast onto a support. The processes of polymerization, cross-linking, and oxidation to silica were completed at room temperature within a few days. Upon introduction of a laser dye into the reaction mixture, a chromophore-embodying silica glass film was attained. No additive or surfactant was required to eliminate the typical fracturing of the glasses during the curing step. The process was carried out with dye-embodying poly(hydrogen siloxane) layer of typical thickness of 10-mu-m sandwiched between two poly(methylsiloxane) layers of lower index of refraction, the overall thickness of the assembly being up to 80-mu-m. The absorbance and fluorescence spectra of laser-dye-loaded glass were typical of monomeric chromophores, even at high concentrations of the dyes (> 10(-2) M), and were slightly shifted as oxidation was progressing from (HSiO3/2)n to (SiO2)n. This synthetic method of inorganic supported silica glass films is convenient due to its quickness and simplicity, its capability to maintain high concentrations of discrete guest molecules (> 10(-2) M) in the glass, and the additive-free nature of the dye-embodying glass films (up to 10-mu-m) prepared by it. These SiO2 glass films provide a promising route for nonlinear optics applications such as a two-dimensional dye laser system.
