Preparação e caracterização termo-óptica do vidro Aluminosilicato de Cálcio dopado com Tm2O3

Abstract

In this work we prepared calcium aluminosilicate glasses with 34wt% of SiO2 (CAS) doped with different Tm2O3concentrations. The samples were prepared under vacuum condition in order to eliminate the existence of OH- molecules. This was performed in a specially constructed furnace to operate at high temperatures, about 1600°C. The CAS glasses were characterized in conjunction with low silica calcium aluminosilicate (LSCAS) glass doped with different Tm3+ ions concentrations.The aim was to investigate the influence of the SiO2 concentration on the optical and thermal properties of the CAS and LSCAS glasses doped with ions Tm3+. The characterization was realized using various methods, such as luminescence and lifetime measurements with excitation at 350nm and 465nm . Thermal Lens Spectroscopy was also performed with excitation at 465nm , to determine the fraction of energy converted into heat in both CAS and LSCAS glasses. The results showed that the increase of silica content results in lower cross relaxation processes between the 3H4 3F4: 3H6 3F4 Tm3+ levels as compared to those of the LSCAS glasses. This observation was confirmed through the increase in the ~800nm emission and reduction in that at ~1.8μm for the CAS in relation to LSCAS glasses. In conclusion, the results of this work showed that LSCAS is a better formulation when high emission at ~1.8μm is intended.