One- and two-photon laser spectroscopy of silica gel-doped fluorescent nanoparticles

摘要

One- and two-photon laser spectroscopy of Rhodamine 6G (Rh6G) and Coumarin 153 (C153) dyes embedded in silica nanoparticles with and without TiO_2 scatters was investigated. Silica gel samples with different dye-doped nanoparticle concentrations were prepared as homogeneous bulk disks by the sol-gel method. Fluorescence and lifetime measurements were performed in the bulk matrices as well as in the resulting ground powders under one- and two-photon excitation. The effect of nanoparticles and TiO_2 scatters concentration on the lifetime quenching was evaluated. The results show a reduction of the fluorescence lifetime for increasing concentrations of both dye-doped nanoparticles and TiO_2 scatters. The fluorescence degradation under infrared ultrashort laser pulses was also explored as a function of irradiation time.