Search

In this paper, a vitreous matrix 65TeO2–15Li2O–20ZnO (TLZ) doped with different concentrations of Sm2O3 (0.1, 0.15, 0.2, 0.35, 0.5, and 1.0 mol%) was produced via melt-quenching technique. The influence of the concentration of Sm2O3 ions on physical and thermal properties, and the Raman gain coefficient of TLZ glass samples, has been investigated. From the X-ray diffractograms, it was obtained that adding Sm2O3 ions had no discernible effect on the overall properties of the TLZ glass samples, keeping the amorphous nature of the glass structure. In addition, it was observed that the density of the samples increased with the incorporation of the Sm3+ ions. Furthermore, the molar volume of the TLZ glass samples increased and the oxygen packing density (OPD) decreased, with the insertion of the Sm2O3. These results indicated that the Sm3+ ions are actively involved in the glass structure by forming bonds with the non-bridging oxygen (NBO) species. Another important result was the investigated sample thermal stability (ΔT) that remains constant up to a concentration of 0.15 mol% of Sm2O3 and then increases with the additional Sm2O3. In addition, the Raman analyses, for an excitation at 532 nm, revealed that the incorporation of Sm3+ ions does not significantly affect the Te–O–Te bonding environment. The refractive index of the samples was determined, and it was obtained that the refractive index increased with the incorporation of Sm3+ ions. Finally, the Raman gain coefficient was also investigated for the peaks centered at 988 and 2091 cm−1, and it exhibited a minimum value at a Sm2O3 concentration of approximately 0.5 mol%. In conclusion, these results indicate that the TLZ glass samples are good candidates for high-speed optical communications due to their interesting properties and higher Raman cross-section compared to other glassy systems. [ABSTRACT FROM AUTHOR]

Tellurite glasses are good candidates for high-speed optical communications due to interesting properties and hence they present higher Raman cross section as compared to other glassy systems. In this work, tellurite glasses with 65TeO2-15Li2O-20ZnO (TLZ1) and 60TeO2-15Li2O-25ZnO (TLZ2) compositions and doped with different concentrations of Er2O3 (0.5; 1.0; and 2.0 mol%) were analyzed. The samples were synthetized by conventional melt-quenching method. The Raman gain coefficients of these glasses were obtained from Raman scattering experiments using 532 nm excitation. The Raman results presented a broad bandwidth from 225 to 1160 cm−1 that become broader with Er3+ concentration. Besides that, a slight difference on the 760 cm−1 band was observed with variation of the host composition. The Raman gain spectra presented a quenching effect for concentrations higher than 0.5 mol% and 1.0 mol% of Er2O3 for TLZ1 and TLZ2, respectively. This quenching have been attributed to the variation in TeOx units present in each composition. The Raman gain coefficient increased with Er3+ concentration and these values were two orders of magnitude higher than silicate glasses. Therefore, the materials studied present potential as new media for Raman amplifiers. [ABSTRACT FROM AUTHOR]

In this work, 80TeO2–(20 − x) Na2O–xTiO2 (x = 0, 5, 10 and 20) mol% glasses by melting quenching technique were obtained. Density (ρ) and molar volume (Vm) of these glasses have been investigated. The characterization was performed by X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) and ultraviolet–visible (UV–Vis) spectroscopy. As expected, the Vm values decreased with x increasing, exhibiting a density opposite behavior. DSC, FTIR and UV–Vis results indicated that, with the increasing the TiO2 content, the role of this oxide changes from network modifier to former. In addition, more covalent bonds are formed, reinforcing the network connectivity by increasing the Te–O–Ti inter-chain bounds. These features improved the glassy system thermal and optical properties. [ABSTRACT FROM AUTHOR]