3rd International Conference Laser M2P

J. Phys. IV France 04 (1994) C4-579-C4-582
DOI: 10.1051/jp4:19944139

Site distribution and thermalization effects in europium-doped silica glasses

A. BOUAJAJ¹, A. MONTEIL², C. BOVIER³, M. FERRARI⁴ and A. PIAZZA<sup>4

1</sup>  Physico-Chimie des Matériaux Luminescents, URA 442 du CNRS, Université Lyon I, 43 bd du 11 Novembre 1918, 69622 Villeurbanne, France
²  Laboratoire POMA, Université d'Angers, 2 bd Lavoisier, 49045 Angers cedex, France
³  Département de Physique des Matériaux, URA 172 du CNRS, Université Lyon I, 43 bd du 11 Novembre 1918, 69622 Villeurbanne, France
⁴  CNR, Centro di Fisica degli Stati Aggregati ed Impianto Ionico, via Sommarive 14, 38050 Povo (TN), Italy

Abstract
For the no-phonon transition ⁵D₀ → ⁷F₀ of Eu³⁺ in glasses, obtained by sol-gel route, emission and absorption at low temperature are not resonant. This effect is interpreted by a redistribution of the excitation energy among the different environment for the Eu³⁺ ion. A simple model is used to interpret the temperature evolution of the emission spectra. A good agreement is obtained with experimental results. The experimental emission spectra are simulated using the Boltzmann law and the experimental excitation spectra. The mechanism of redistribution is a phonon-assisted energy transfer process. This is confirmed by temperature dependance of decays and time resolved emission measurements.

© EDP Sciences 1994