Er-doped phosphate glasses were fabricated by melt-quenching technique. The changes in their thermal, structural and luminescence properties with the addition of Al2O3, TiO2 or ZnO were studied.Physical and thermal properties were investigated through density measurement and differential thermal analysis. Structural characterization was performed using the Raman and Infrared spectroscopy. In order to study the influence of the composition on the luminescence properties of the glasses, the refractive index, the luminescence spectra and the lifetime values were measured.The results show that with the addition of Al2O3 and TiO2 the phosphate network becomes more connected increasing the glass transition temperature, whereas the addition of ZnO does not show 2 significant changes in the optical, thermal and structural properties but it leads to a larger emission cross-section at 1540 nm as compared to the other glasses. As the site of the Er 3+ is not strongly affected by the change in the glass composition, we think that the emission properties of the glasses depend on the glass structure connectivity, which has an impact on the Er 3+ ions solubility.

Er-doped phosphate glass ceramics were fabricated by melt-quenching technique followed by a heat treatment. The effect of the crystallization on the structural and luminescence properties of phosphate glasses containing Al2O3, TiO2, and ZnO was investigated. The morphological and structural properties of the glass ceramics were characterized by Field Emission-Scanning Electron Microscopy (FE-SEM), X-ray Diffraction (XRD), and micro-Raman spectroscopy. Additionally, the luminescence spectra and the lifetime values were measured in order to study the influence of the crystallization on the spectroscopic properties of the glasses. The volume ratio between the crystal and the glassy phases increased along with the duration of the heat treatment. The crystallization of the glass ceramics was confirmed by the presence of sharp peaks in the XRD patterns and different crystal phases were identified depending on the glass composition. Sr(PO3)2 crystals were found to precipitate in all the investigated glasses. As evidenced by the spectroscopic properties, the site of the Er3+ ions was not strongly affected by the heat treatment except for the fully crystallized glass ceramic which does not contain Al2O3, TiO2, and ZnO. An increase of the lifetime was also observed after the heat treatment of this glass. Therefore, we suspect that the Er3+ ions are incorporated in the precipitated crystals only in this glass ceramic.

The aim of this study was to fabricate a bioactive optical fiber able to monitor “in situ” its reaction with the body through changes in its optical properties. Core and cladding preforms were prepared with the composition (97.25*(0.50P2O5‐0.40SrO‐0.10Na2O)‐2.5ZnO‐0.25Er2O3) and (98.25*(0.50P2O5‐0.40SrO‐0.10Na2O)‐1.75ZnO) (in mol%), respectively, and successfully drawn into a multimode core/clad optical fiber. Optical and near‐Infrared images assessed the proper light guiding properties of the fiber. The fibers favor the precipitation of a Ca‐P reactive layer at its surface concomitant with a reduction in the fiber diameter, when immersed in SBF, often assigned as a sign of bioactivity. It is clearly shown here that the bio‐response of the fiber upon immersion in SBF can be tracked from the decrease in the intensity of the Er3+ ions emission at 1.5 µm. This confirms that the newly developed optical fiber, which combines good optical properties with a suitable bioactive behavior, is a promising platform for the development of novel biomedical devices for biophotonic and photomedical applications. Finally, the successful splicing of the newly developed fiber with commercial optical fibers was an evidence of the possibility to integrate the newly developed phosphate fiber within existing components used in the field of biomedicine.