Concentration dependent enhanced luminescence and its quenching effect in erbium incorporated heavy metal oxide—borate glasses

Erbium incorporated zinc-lead-bismuth-borate glasses are prepared through melt-quenching technique and their concentrated dependent structural, thermal and spectroscopic properties are evaluated. Prepared glasses are thermally stable and amorphous nature and the density and refractive indices of the prepared glasses increases with Er₂O₃ concentration. UV–vis-NIR spectra exhibits multiple transitions accompanied by hyper sensitive transition of ⁴I_15/2 → ²H_11/2. Theoretical Judd-Oflet calculations were performed and correlated with experimental results. JO and bonding parameters reveal the covalence nature of the prepared glasses and radiative probabilities shows highest branching ratio for ⁴I_15/2 → ²H_11/2 transition. Luminescence results exhibit luminescence enhancement up to 1 mol% of erbium and thereafter luminescence quenches due to the existence of cross-relaxation channels. Using McCumber's theory, absorption and emission cross-section values are estimated and are in agreement with each other and as well as with the experimental stimulated cross-sectional values. About 40% population inversion is achieved for the prepared glasses. Therefore, the investigated results suggest that, the prepared glasses are suitable candidates for amplifier applications. (paper)