R. Morea

Spectral study of the stimulated emission of Nd 3+ in fluorotellurite bulk glass

In this work we present, for the first time to our knowledge, laser emission under wavelength selective laser-pulsed pumping in Nd(3+)-doped TeO(2)-ZnO-ZnF(2) bulk glass for two different Nd(3+) concentrations. The fluorescence properties of Nd(3+) ions in this matrix which include, Judd-Ofelt calculation, stimulated emission cross-section of the laser transition and lifetimes are also presented. The site-selective emission and excitation spectra along the (4)I(9/2)→(4)F(3/2) absorption band show the inhomogeneous behaviour of the crystal field felt by Nd(3+) ions in this fluorotellurite glass which allows for spectral tuning of the laser output pulse as a function of the pumping wavelength. The emission cross-section obtained from the Judd-Ofelt analysis and spectral data (4.9x10(-20) cm(2)) is in fairly good agreement with the value obtained from the analysis of the laser threshold data (4x10(-20) cm(2)).

Active Mid-IR emissions from rare-earth doped tellurite glass ceramics for bio applications

Intense emission peaking at 2.18 μm was successfully obtained from erbium upon carefully designed engineering of its glass host both thermally and spectroscopically. Highly localized crystallization of erbium sites is verified by micro Raman and micro-PL along with TEM characterizations.

Luminescence of Er3+ Ions in Nanocrystalline Glass-Ceramics

This work analyzes the influence of the nanocrystals on the luminescence properties of Er3+ions in transparent oxyfluoride tellurite glass-ceramics obtained by heat treatment of the precursor Er-doped glass. The comparison between the fluorescence properties of Er-doped glass and glass-ceramic suggests that a fraction of Er3+ ions are forming nanocrystals while the rest remain in a glass environment. The presence of ErF3 nanocrystals has a strong effect in the upconverted red emission from4F9/2 level. The time evolution of the upconverted red emission shows that energy transfer upconversion processes are responsible for the increase of this emission in the glass-ceramic sample.

Luminescence properties of Er 3+ ions in nanocrystalline glass-ceramics

In this work, we analyze the influence of the nanocrystallization process on the luminescence properties of Er3+ ions in transparent oxyfluoride tellurite glass-ceramics obtained by heat treatment of the precursor Er-doped glass. The comparison between the fluorescence properties of Er-doped glass and glass-ceramics suggests that a fraction of Er3+ ions are forming nanocrystals while the rest remain in a glass environment. The presence of fluoride nanocrystals has a strong effect in the upconverted red emission from 4F9/2 level. This emission increases significantly as compared with the green one in the glass-ceramic sample. The time evolution of the upconverted red emission shows that energy transfer upconversion processes are responsible for the increase of this emission in the glass-ceramic samples.