Er3+ -doped CaSO4-P2O5 glasses with successive increase in Er2O3 contents (from 0.1 to 0.9 mol %) were prepared using melt-quench method aimed to improve their chemical stability and optical behavior. The structure was investigated using FT-infrared and Raman spectroscopy. Non-crystalline phases were detected by X-ray diffraction (XRD) spectroscopy. From the Raman spectra, Qi were identified (i = 0, 1, 2 and 3) stands for the number of bridging oxygen per PO4 tetrahedra, meta- and pyro-phosphate units were observed. The structure indicates that meta-phosphate (Q2) and Q1 units are more predominant during the modification process (de-polymerization). The vibrational frequencies (as symmetric, asymmetric, harmonic bending and ionic group) were observed in Raman and IR spectra. The spectroscopic properties of materials have been characterized in order to assess their potential for solid state lasers and other photonic devices. The UV–Vis-NIR absorption spectra fitting were used to calculate the optical band gap (Eg), bonding parameters (δ) and root mean square deviation (σrms) of the glass samples. The experimental and theoretical oscillator strength in Judd-Ofelt (JO) parameter was identified, the radiative properties like transition probability (A), branching ration (βR) and radiative lifetime (τR) for the transition in the spectra were determine and reported. Other physical properties like density, molar volume were determined with Archimedes method. The results suggest that the glass system is a potential for functional glasses.

Keywords: Judd–Ofelt analysis, Phosphate, Raman, Density, Spectroscopy, Er3+