Composition Dependence of the Judd-Ofelt Intensity Parameters in TeO 2 -PbF 2 : Tm 3 + Glasses
- PDF / 107,520 Bytes
- 5 Pages / 612 x 792 pts (letter) Page_size
- 37 Downloads / 167 Views
B9.10.1
Composition Dependence of the Judd-Ofelt Intensity Parameters in TeO2-PbF2 : Tm3+ Glasses Idris Kabalci1, GonulOzen1, Adnan Kurt2, Alphan Sennaroglu2 1 Department of Physics, Istanbul Technical University, Maslak-Istanbul, 34469 2 Laser Research Laboratory, department of Physics and Electrical Electronics Engineering, Koc University, Sariyer, Istanbul, Turkey.
ABSTRACT Tm3+ -doped glasses with the composition of (1-x)TeO2-xPbF2, where x=10, 15, 20, 25 mol.% were synthesized and, their thermal and absorption measurements were investigated. All the glasses were transparent. The absorption bands corresponding to the absorption of the 1G4, 3F2, 3 F3, 3F4, 3H5, and 3H4 levels from the 3H6 ground level of the Tm3+ ion were observed in the optical UV/VIS/NIR absorption measurements. We calculated the integrated absorption cross sections of each band except that of 3H5 level was found to vary with composition of the PbF2. The absorption measurements were first made to determine the spontaneous emission probabilities of the 4f-4f transitions of the Tm3+ ions. The calculations were made by using the Judd - Ofelt theory. The Ω2 parameter shows the strongest dependence on the host composition and it increases with the increasing PbF2 amount. The values Ω4 increases rather slowly while the value of Ω6 is practically independent of the composition. The strong dependence of the parameter Ω2 indicates that this parameter is related to the structural change and symmetry of the local environment of the Tm3+ ions in this glass.
INTRODUCTION Until now, the optical amplifiers have been made of rare-earth doped silica glasses although their phonon cut-off frequency is high [1]. Several researchers have pointed out that SiO2 is not a suitable host for rare-earth ions because the ions tend to form clusters in the silica network. This clustering results in the concentration quenching of luminescence due to the cross-relaxation processes between the neighbouring ions [2]. In our studies, tellurite based-glass hosts were preferred because of their favorable physical characteristics such as low melting temperature, high refractive index, good infrared transmission, and low phonon energy. In addition, tellurite glasses are resistant to atmospheric moisture and large concentrations of rare-earth ions can be incorporated into the glass matrix. Since TeO2 cannot form a glass structure by itself, dopants such as PbF2 are added to form TeO2-based bulk glasses. In this study, the effect of PbF2 content on the thermal properties and the spontaneous transition probabilities of 1.0 mol.% Tm3+ in (1-x)TeO2-xPbF2 glasses were investigated by means the UV/VIS/NIR absorption measurements. Experimental In the experiments, glass host samples were prepared with the compositions of (1-x)TeO2-xPbF2, where x=10, 15, 20, and 25 mol.%. A series of 1.0 mol.% Tm2O3 doped glasses were also
B9.10.2
prepared using the same temperature arrangement used for the preparation of the undoped glasses. We used reagent-grade TeO2 (99.999% purity, Aldrich Chemical C
Data Loading...
