Confocal microscopy for characterization of porous sol-gel glasses incorporating luminescent dyes

Porous glasses were prepared using the sol-gel method. The mix of catalysts used during preparation was changed in order to produce two glasses with t wo different densities. Fluorescent dyes were incorporated into these glass es by diffusion into the glass. The resulting fluorescent glasses were char acterized using confocal microscopy, which allows thin optical sections to be imaged at up to 200 mum below the sample surface. In addition, fluoresce nce recovery after photobleaching (FRAP) was used to demonstrate diffusion of the dye within wet samples. The results demonstrate the potential for no n-invasive optical characterization of fluorescent sol-gel glasses, and in particular local measurement of diffusion coefficients within the glass mat rix. (C) 2001 Elsevier Science B.V. All rights reserved.