Investigation of the aluminum oxide content on structural and optical properties of germanium glasses doped with RE ions.

In this paper structural and optical properties of Rare Earth doped (RE) gallo-germanate glasses modified with various amount of Al2O3 have been investigated. Glasses doped with Yb3+, Tm3+, and Ho3+ ions were synthesized to study Al2O3 additive influence on their structural and emission properties in the visible spectral region. MIR spectra indicated that the structure of prepared glasses tends to order and its polymerization along with the aluminum content increase. Glass samples consisting of the low molar content of Al2O3 are characterized by a significant contribution of Tm3+ ions in light emission while Ho3+ ions luminescence dominates in samples consisting of the higher molar content of Al2O3. Additionally, investigation of light emission in visible range showed that samples consisting of the low molar content of Al2O3 are characterized by greenish blue light emission whereas light emitted by samples consisting of 15-20 mol% is much closer to the white colour.

Analysis of upconversion luminescence in germanate glass and optical fiber codoped with Yb3+/Tb3+.

In this paper, upconversion (UC) luminescence processes in a GeO2-Ga2O3-BaO glass system codoped with 0.7Yb2O3/(0.07-0.7)Tb2O3 (mol.%) and double-clad optical fiber codoped with 0.7Yb2O3/0.7Tb2O3 (mol.%) were investigated. The highest emission intensity (energy transfer efficiency equals 12.92%) was obtained for 0.7Yb2O3/0.7Tb2O3 codoped glass. Comparative analysis showed significant differences in the shape of luminescence of fabricated germanate glass and optical fiber. Due to dominant transition from D45 sublevel the main green UC peak (Tb3+: D45→F57) of fabricated double-clad optical fiber is shifted by 4 nm toward longer wavelengths.

Rare earth-doped lead borate glasses and transparent glass-ceramics: structure-property relationship.

Correlation between structure and optical properties of rare earth ions in lead borate glasses and glass-ceramics was evidenced by X-ray-diffraction, Raman, FT-IR and luminescence spectroscopy. The rare earths were limited to Eu(3+) and Er(3+) ions. The observed BO(3)↔BO(4) conversion strongly depends on the relative PbO/B(2)O(3) ratios in glass composition, giving important contribution to the luminescence intensities associated to (5)D(0)-(7)F(2) and (5)D(0)-(7)F(1) transitions of Eu(3+). The near-infrared luminescence and up-conversion spectra for Er(3+) ions in lead borate glasses before and after heat treatment were measured. The more intense and narrowing luminescence lines suggest partial incorporation of Er(3+) ions into the orthorhombic PbF(2) crystalline phase, which was identified using X-ray diffraction analysis.