Enhancing the absorption cross section of rare earth by silver metallic nanoparticles

Tb3+/Yb3+ doped silica-Hafnia glass and glass ceramic planar waveguides have been elaborated by sol-gel route using dip-coating method. To increase the efficiency of these planar waveguides an additional doping with silver metallic species able to work as sensitizers. The introduction of silver in silica-Hafnia glass and glass ceramic films was obtained by immersion of Tb3+/Yb3+ co-doped 70SiO2−30HfO2 waveguides in molten salt bath containing silver nanoparticles, the films were subsequently annealed in air at different temperatures to induce the migration of Ag. After excitation at 377 nm of the glass sample, photoluminescence spectra shows a very intense broadband emission in the violet-blue spectral region and this emission is strongly reduced after annealing due to an out-diffusion of Ag from the sample.