Laser beam irradiation of silver doped silicate glasses

Planar light waveguides prepared by Ag–Na ion exchange in molten salt bath are irradiated with Nd:YAG laser beams at different wavelengths in the IR and VIS regions, and for different energy density and repetition rate values. The samples are characterized by optical spectroscopy to determine the role of irradiation parameters in the Ag clustering process, including aggregation phenomena and possible cluster photofragmentation. The appearance of the characteristic plasmon resonance feature in the optical absorption spectra marks the formation of Ag clusters, as observed by electronic microscopy as well, and permits to follow the evolution of the whole clustering process upon increasing of the deposited energy density. Photoluminescence spectroscopy has given specific information concerning the presence of Ag multimeric aggregates, considered as embryonic structures for the growing nanoclusters. The systematic investigation presented in this work is expected to clarify some aspects of the interaction between the laser beam and the doped glass matrix, and to help establishing suitable methodologies for the controlled preparation of nanocomposite glasses.