An Investigation of the Photonic Application of TeO2-K2TeO3-Nb2O5-BaF2 Glass Co-Doped with Er2O3/Ho2O3 and Er2O3/Yb2O3 at 1.54 µm Based on Its Thermal and Luminescence Properties.

A glass composition using TeO2-K2TeO3-Nb2O5-BaF2 co-doped with Er2O3/Ho2O3 and Er2O3/Yb2O3 was successfully fabricated. Its thermal stability and physical parameters were studied, and luminescence spectroscopy of the fabricated glasses was conducted. The optical band gap, Eopt, decreased from 2.689 to 2.663 eV following the substitution of Ho2O3 with Yb2O3. The values of the refractive index, third-order nonlinear optical susceptibility (χ(3)), and nonlinear refractive index (n2) of the fabricated glasses were estimated. Furthermore, the Judd-Ofelt intensity parameters Ωt (t=2,4,6), radiative properties such as transition probabilities (Aed), magnetic dipole-type transition probabilities (Amd), branching ratios (ß), and radiative lifetime (τ) of the fabricated glasses were evaluated. The emission cross-section and FWHM of the 4I13/2→4I15/2 transition around 1.54 µm of the glass were reported, and the emission intensity of the visible signal was studied under 980 nm laser excitation. The material might be a useful candidate for solid lasers and nonlinear amplifier devices, especially in the communications bands.

Investigation of Thermal and Spectroscopic Properties of Tellurite-Based Glasses Doped with Rare-Earth Oxides for Infrared Solid-State Lasers.

The thermal and optical properties of 60TeO2-20K2TeO3-10WO3-10Nb2O5 (in mol%) glasses doped with Ho2O3, Er2O3, and Tm2O3 were explored in the present work. The thermal stability, refractive index n, extinction coefficient k, absorption coefficient α, and optical band gap of the glasses were evaluated. The UV-Vis-NIR absorption spectra, the Judd-Ofelt intensity parameter, the spectroscopic quality factor, and the emission and absorption cross-sections were calculated to investigate the effects of Er3+ and Tm3+, respectively, on the band spectroscopic properties of Ho3+ ions. The results showed that the maximum emission cross-section was approximately 8×10-21 cm2, and the values of the full width at half maximum (FWHM), quality factor (σe×FWHM), and gain coefficient of Ho3+: 5I7→5I8 were also reported. The value of the FWHM×σe was 1200×10-28 cm3, which showed greater gain characteristics than earlier study results. For 2 µm mid-infrared solid-state lasers, the glasses that were examined might be a good host material.

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.