Optical Absorption and Fluorescence Properties of Er~(3+) / Yb~(3+) Codoped Lead Bismuth Alumina Borate Glasses

摘要

Lead bismuth alumina borate glasses codoped with Er~(3+)/Yb~(3+) were prepared by melt quenching technique. Optical absorption, FTIR and photoluminescence spectra of these glasses have been studied. Judd-Ofelt theory has been applied to to the f ? f transitions for evaluating Ω_2, Ω_4 and Ω_6 parameters. Radiative properties like branching ratio β_r and the radiative life time τ_R have been determined on the basis of Judd-Ofelt theory. Upconversion emissions have been observed under 980nm laser excitation at room temperature. Green and red up-conversion emissions are centered at 530, 550 and 656 nm corresponding to ~2H_(11/2) →~4I_(15/2), ~4S_(3/2) →~4I_(15/2) and ~4F_(9/2) →~4I_(15/2) transitions of Er~(3+) respectively. The results obtained are discussed quantitatively based on the energy transfer between Yb~(3+) and Er~(3+).