Enhanced luminescence properties of Er3+/Yb3+ doped zinc tellurofluoroborate glasses for 1.5 µm optical amplification

The spectroscopic investigations on optical absorption, Visible emission, NIR emission and upconversion emission of Er3+/Yb3+ doped zinc tellurofluoroborate glasses have been studied to explore the amplification properties. The bonding parameters (δ and β), oscillator strengths and Judd-Ofelt (JO) intensity parameters were calculated from the absorption spectra. Oscillator strength values of the hypersensitive transitions 4I15/2→4G11/2 and 4I15/2→2H11/2 possess higher values compared to the other transitions. The higher values of the Ω2 parameter and smaller values of the Ω6 parameter indicate the lower symmetry in the prepared glasses. The luminescent intensity corresponding to the 4I13/2→4I15/2 transition changes with the change in Er2O3 content and is due to the energy transfer process taking place between Yb3+ and Er3+ ions. The absorption and emission cross-section values for the 4I13/2→4I15/2 emission band have been calculated using McCumber theory and the Gain cross-section for the 4I13/2→4I15/2 emission transition also obtained. The emission cross-section of 1.53 µm emission band was calculated to be of the order of 1.29×10−20 cm2 by using the McCumber theory.