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 (delta and beta), oscillator strengths and Judd-Ofelt (JO) intensity parameters were calculated from the absorption spectra. Oscillator strength values of the hypersensitive transitions I-4(15/2) ->(4)G(11/2) and I-4(15/2) -> H-2(1 1 /2) possess higher values compared to the oilier transitions. The higher values of the Omega(2) parameter and smaller values of the Omega(6) parameter indicate the lower symmetry in the prepared glasses. The luminescent intensity corresponding to the 4I(13/2) -> I-4(15/2) transition changes with the change in Er3+ content and is due to the energy transfer process taking place between Yb3+ and Er'' ions. The absorption and emission cross-section values for the I-4(13/2) -> I-4(15/2) emission band have been calculated using McCumber theory and the Gain cross-section for the I-4(13/2) -> I-4(15/2) emission transition also obtained. The emission cross-section of 1.53 mu m emission band was calculated to be of the order of 1.29x102 cm' by using the McCumber theory.