Role of TeO2 coordination with the BaF2 and Bi2O3 on structural and emission properties in Nd3+ doped fluoro phosphate glasses for NIR 1.058 μm laser emission

Abstract Fluoro phosphate glasses with different contents of barium and bismuth (8, 11, 14, 17 and 20 mol %) doped with Nd3+ were prepared by melt quenching technique. Importance of these modifier ions on structural transformation were carried out using XRD, FTIR, FT-Raman and 31P MAS NMR characterizations. 31P MAS NMR spectra revealed that structural modifications due to Bi2O3 are more when compared with BaF2 in this fluoro phosphate glass matrix. Three phenomenological Judd-Ofelt (J-O) parameters Ωλ (λ = 2, 4, 6) have been derived from the absorption spectra of Nd3+ doped barium and bismuth fluoro phosphate glasses. From the Judd-Ofelt parameters, transition probabilities (A), branching ratios (β) of certain transitions and radiative lifetimes of certain excited states of Nd3+ are extracted and reported. From the emission spectra, emission cross sections (σe), band gains (σexΔλeff) and optical gain parameters (σexτR) were reckoned for the observed emission bands in these phosphate glasses. It is observed that barium glass resulted higher laser spectroscopic parameters (σe, σexΔλeff, σexτR) which are crucial characteristics for exploring promising laser applications. Impact of Ba2+ and Bi3+ on luminescent properties of Nd3+ doped fluoro phosphate glasses has been examined in search of solid sate gain medium for laser emitting NIR light around 1.058 μm for photonic applications.