Optical characterization of Tm(3+) doped Bi2O3-GeO2-Ga2O3 glasses in absence and presence of BaF2

2-3 μm mid-infrared luminescence of Ho3+/Yb3+ co-doped chloride-modified fluorotellurite glass

In this paper, Ho³⁺/Yb³⁺ co-doped chloride-modified fluorotellurite glasses with 2-3 μm mid-infrared luminescence are prepared. By measuring and investigating the transmission spectra and emission spectra, the prepared glasses show a high transmittance (91 %) and low maximum phonon energy (813 cm^-1). Based on the measured absorption spectra, the Judd-Ofelt parameters and radiation characteristics were calculated in depth. In addition, with the assistance of phonons, the energy transfer between Ho³⁺/Yb³⁺ ions further increases the mid-infrared fluorescence intensity. The calculated emission cross-section at 2.0 μm and 2.85 μm reach 16.47 × 10^-21 cm² and 7.8 × 10^-21 cm², respectively. It is worth mentioning that the quantum efficiencies of Ho³⁺: ⁵I₇→⁵I₈ and ⁵I₆→⁵I₇ reach 51.47 % and 84.14 % respectively. The results having also in mind good thermal stability (ΔT = 102℃) and refractive index (n = 1.645) indicate that this glass has a promising application for the study of fiber lasers in the mid-infrared band.

Thermal Stability, Optical Properties, and Gamma Shielding Properties of Tellurite Glass Modified with Potassium Chloride

The synthesized glass system with a composition of (80-x) TeO2-10P2O5-10Nb2O5-xKCl mol% (where x = 5, 10, 15, 20, and 25) was successfully fabricated. The density (ρ) and molar volume (Vm) have been calculated. The investigated glasses were characterized using different analysis methods (differential thermal analysis (DTA) and UV-VIS-NIR spectroscopy). The radiation shielding effectiveness of the synthesized glass system was evaluated using different shielding parameters, such as mass and linear attenuation coefficients (MAC, LAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), and effective electron number (Neff). The results showed that with the increasing potassium chloride (KCl) concentration and decreasing tellurium oxide (TeO2) concentration, the density, refractive index, Urbach energy (Eu), and glass transition temperature (Tg) decreased, while the optical energy gap (Eopt) and thermal stability increased. As the KCl concentration increases, the values of MAC, LAC, and Zeff increase in the following order: TPNK5 % > TPNK10 % > TPNK15 % > TPNK20 % > TPNK25 %. Additionally, the shielding effectiveness of TPNK glass system showed good performance compared with some standard materials. The synthesized glass with a minimum KCl content has both good shielding effectiveness and good optical properties, in addition to reasonable thermal stability, which makes it suitable for shielding and optical applications.