A comparison of the spectroscopic properties of Eu3+-doped fluoride and oxide glasses under high-power, picosecond-pulse excitation

Abstract

The frequency harmonic outputs of a Nd:YAG laser were used to excite Eu3+ ions in fluoride and oxide glasses with high-power, picosecond pulses. Time-resolved fluorescence spectra, fluorescence lifetimes, and rise times were measured on the fluoride glass to obtain information about the two-photon absorption transitions and the radiative and radiationless decay processes. The results show the importance of coherence in the intermediate state of the two-photon transition observed with 532.0-nm pumping. Multiphoton pumping with 345.7-nm excitation results in spectral shifts and lifetime changes which are attributed to local polarization effects. Similar experiments were performed on the oxide glass, and the results were found to be significantly different because of the more efficient radiationless decay processes in the oxide host compared to the fluoride host.