EN
Modification of the spontaneous emission of dye molecules embedded in artificial opals exhibiting stop bands in the visible range is observed. Molecules embedded in artificial opals show dips in spontaneous emission spectra and modified fluorescence decay kinetics. Results are interpreted in terms of redistribution of the photon density of states. Effects of the multiple reabsorption and reemission of fluorescence photons and interaction of dye molecules with the silica surface are discussed.