The dyes oxazine 725, 7-acetoxy-4-methyl coumarin, O-4-methylcoumarinyl-N-[3-(triethoxysilyl)-propyl] carbamate and 2′,7′-dichlorofluorescein were introduced during the acid-catalyzed cohydrolysis of various molar ratios of tetraethoxysilane (TEOS) and the gel modifers, diethoxydimethylsilane (DEDMS) or diethoxymethylvinylsilane (DEMVS). The morphological features and optical absorption spectra of the resulting dye doped gels were followed during subsequent drying and heating. For DEDMS-TEOS molar ratios less than 1.375, gel cracking during drying was a problem. DEDMS-TEOS molar ratios greater than 2.750 yielded optically transparent monoliths, but did not allow for sufficient incorporation of dye to be useful. However, the functionalized dye, 0-4-methylcoumarinyl-N-[3-(triethoxysilyl)-propyl] carbamate, appeared to be significantly more soluble in such a highly modified matrix. Compared to matrices derived from pure TEOS the DEDMS or DEMVS modified matrices provided oxazine 725 doped with improved thermal stabilities. Finally, the 2′,7′-dichlorofluorescein doped dimethylsiloxane-oxide matrix showed good thermal stability in its optical properties, having significant optical absorption and little change in the wavelength of the absorption maximum after heating to 300°C.