Rolindes Balda

Investigation of site-selective symmetries of Eu3+ ions in KPb2Cl5 by using optical spectroscopy.

Site-selective time-resolved spectroscopy of Eu3+ in KPb2Cl5 has been investigated by using fluorescence line narrowing technique. A crystal field analysis and simulation of the experimental results has been performed in order to parametrize the crystal field at the Eu3+ sites. Three symmetry independent crystal field sites for the rare-earth ion in this crystal were found. A plausible argument about the crystallographic nature of these sites is given.

Study of the Cr3+ sensitization and structural disorder effects on the Nd3+ laser action in Ca-gallogermanate-type codoped crystals

Abstract Energy transfer between Cr 3+ and Nd 3+ ions in Ca 3 Ga 2 Ge 4 O 14 (CGG) and La 3 Ga 2 SiO 14 (LGS) crystals has been investigated in the 4.2–300 K temperature range by using steady-state and site-selective time-resolved laser spectrometry. The transfer efficiency was calculated as a function of temperature by using the Cr 3+ lifetimes of the single doped and co-doped samples. Laser experiments were carried out in a diffusive cavity by pumping the co-doped rods of CGG and LGS crystals with xenon flashlamps. The laser spectral emission shows a complex structure which varies as a function of pump energy. The temporal evolution of the laser spectrum is discussed in terms of a simple four-level spectral rate-equation laser model by considering the influence of the crystal field disorder on the spectral properties of Nd 3+ ions.

Optical properties of a Cr3+-doped fluorophosphate glass investigated by steady state and time-resolved laser spectroscopy

The optical properties of trivalent-chromium-doped fluorophosphate glass (21.74 Al(PO3)3-57.8 BaF2-19.96 AlF3 (wt.%)) have been investigated in the 4.2-300 K temperature range using steady state and time-resolved laser spectroscopy. The luminescence of Cr3+ shows a strong thermal quenching which can be analysed in terms of the quantum mechanical single-configurational coordinate model. In order to establish a correlation between the glass matrix composition and the spectral and temperature behaviour of the Cr3+ photoluminescence, detailed time-resolved measurements have been performed. When compared with fluoride glasses, the results attained for the emission wavelength dependence of the lifetimes and excitation spectra show an enhancement of the site-dependent effects.