Comparison of the Spectroscopic Properties of Eu(3+)-Doped Fluoride and Oxide Glasses Under High-Power, Picosecond-Pulse Excitation

摘要

Time-resolved spectroscopy, with the use of high-power, picosecond-pulse excitation, has been shown to be an important technique for studying the spectral dynamics of trivalent rare-earth ions in solids. We report the results of a detailed investigation of the spectroscopic properties of BZLT fluoride glass doped with Eu ions with the use of the picosecond pulses from the primary and various harmonics of the output of a Nd:YAG laser as the source of excitation. In addition, similar measurements were made on Eu -doped lithium phosphate (LP) oxide glass to determine the effects of the host lattice on the spectroscopic properties with this type of excitation. The time-resolved fluorescence spectra, fluorescence lifetimes, and rise times were measured as a function of laser power for the various excitation frequencies. The spectral properties are analyzed in terms of single- and two-photon absorption processes and fluorescence from four different metastable states. These results are especially interesting, since little spectroscopic work has been reported on rare-earth ions in this type of fluoride glass host.