Structural studies of tellurite glasses doped with erbium ions

Investigation of emission characteristics in Er3+- doped bismuth phosphate glasses for NIR laser materials

Bismuth flourophosphate glasses doped with Er3+ ions (0.5 mol %) were synthesized using different modifier fluorides with the aid of melt quenching route. The glass samples were labelled as PBiBaAFT (where AF = Li, Na, Mg, K, Ca and Sr fluorides). The influence of cations of network modifiers on the structure and thereby spectroscopic properties of Er3+ ions was analysed via Powder XRD, FTIR, optical absorption and photoluminescence. Existence of relevant vibrational groups and modifications in structure due to the different admixture modifier cations were recognized via FTIR spectra. The Judd-Ofelt parameters abide by the trend Ω2 > Ω6 > Ω4 in the PBiBaLiT, PBiBaKT, PBiBaCaTand PBiBaSrT glasses whereas the trend was noticed to be Ω2 > Ω4 > Ω6 for PBBiNaT and PBiBaMgT glasses respectively. The visible emission spectra were recorded by exciting at 379 nm exhibit three emission bands centered at 526 nm, 544 nm and 686 nm. NIR emission spectra were recorded by exciting at 980 nm exhibit broad emission at 1535 nm. Admixture of different cations could exhibit change in luminescence intensity and radiative parameters of the prepared glasses. Spectroscopic parameters such as radiative transition probability (A), branching ratio (β), absorption cross section (∑), effective bandwidth (Δλeff) and optical band gain (σe × Δλeff) are calculated. The mid infrared spectroscopic features were investigated.

Tellurite Glasses from the 70TeO2-5XO-10P2O5-10ZnO-5PbF2(X= Pb, Bi, Ti) System Doped Erbium Ions-The Influence of Erbium on the Structure and Physical Properties

In this article, we present research on the influence of erbium ions on the structure and magneto-optical properties of 70TeO₂-5XO-10P₂O₅-10ZnO-5PbF₂ (X = Pb, Bi, Ti) tellurite glass systems. Structural changes occurring in the glasses during doping with erbium ions were investigated using positron annihilation lifetime spectroscopy (PALS) and Raman spectroscopy. The X-ray diffraction (XRD) method was used to confirm the amorphous structure of the investigated samples. Based on the Faraday effect measurements and calculated values of Verdet constant, the magneto-optical properties of the glasses were determined.

Effect of Yb3+ on the Structural and Visible to Near-Infrared Wavelength Photoluminescence Properties in Sm3+-Yb3+-Codoped Barium Fluorotellurite Glasses

We report on the Sm³⁺ and Sm³⁺:Yb³⁺-doped barium fluorotellurite glasses prepared using the conventional melting and quenching method. The spectroscopic characterisations were investigated with Raman and FTIR to evaluate the glasses’ structural and hydroxyl (-OH) content. The Raman analysis revealed a structural modification in the glass network upon adding and increasing the Yb³⁺ concentration from a TeO₃ trigonal pyramid to a TeO₄ trigonal bi-pyramid polyhedral. At the same time, the FTIR measurements showed the existence of -OH groups in the glass. Thus, under the current experimental conditions and nominal composition, the -OH group contents are too large to enable an effective removal. The near-infrared region of the absorption spectra is employed to determine the nephelauxetic ratio and bonding parameters. The average nephelauxetic ratio decreases, and the bonding parameter increases with the increasing Yb³⁺ content in the glasses. A room temperature visible and near-infrared photoluminescence ranging from 500 to 1500 nm in wavelength and decay properties were investigated for glasses doped with Sm³⁺ and Sm³⁺-Yb³⁺ by exciting them with 450 and 980 nm laser sources. Exciting the Sm³⁺- and Sm³⁺-Yb³⁺-doped glasses by 450 nm excitation reveals a new series of photoluminescence emissions at 1200, 1293, and 1418 nm, corresponding to the ⁶F_11/2 state to the ⁶H_J (J = 7/2, 9/2, 11/2) transitions. Under the 976 nm laser excitation, a broad photoluminescence emission from 980 to 1200 nm was detected. A decay lifetime decreased from ~244 to ~43 μs by increasing the Yb³⁺ content, ascribing to concentration quenching and the OH content.