Visible, Up-conversion and NIR (~1.5 μm) luminescence studies of Er3+ doped Zinc Alumino Bismuth Borate glasses

Er3+ doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses with composition 20ZnO+10Al2O3+(10−x)Bi2O3+60B2O3+xEr2O3 (where x=0.1, 0.5, 1.0 and 2.0 mol%) were prepared by using a melt quenching technique to study their luminescence efficiency in different regions of electromagnetic spectrum using absorption, emission, up-conversion and time resolved photoluminescence spectral studies at room temperature. The Judd-Ofelt (JO) parameters evaluated by applying JO theory to the absorption spectra of Er3+ doped ZnAlBiB glasses were used to calculate the radiative properties such as transition probability (AR), Branching ratios (βR), radiative lifetimes (τR), stimulated emission cross-section (σse), gain band width (σse×ΔλP) and optical gain (σse×τR) parameters for the prominent luminescent levels of Er3+. Visible and near infra-red (NIR) emission spectra have been recorded by exciting the glass samples at 486 nm and 980 nm respectively. Quantum efficiency (η) values for the prepared glasses were evaluated from the decay curves recorded for the NIR transition 4I13/2→4I15/2. The up-conversion luminescence shown by these glasses were recorded and analysed to understand utility of these glasses as up-conversion lasers by exciting them with 980 nm laser diode. The visible, up-conversion and NIR luminescence studies indicate that Er3+ ions doped ZnAlBiB glasses are aptly suitable for solid state lasers and optical amplifiers.