Investigations on luminescence behavior of Er3+/Yb3+ co-doped boro-tellurite glasses

Abstract

Er3+/Yb3+ co-doped boro-tellurite glasses with the chemical composition 30TeO2+(24−x)B2O3+15SrO+10BaO+10Li2O+10LiF+1Er2O3+xYb2O3 (where x=0, 0.1, 0.5, 1 and 2 in wt%) have been prepared and their luminescence behavior were studied and reported. Absorption spectral measurements have been used to derive the Judd–Ofelt (JO) intensity parameters from the experimental and calculated oscillator strength values following the JO theory. The various lasing parameters such as stimulated emission cross-section (σEp), experimental and calculated branching ratios (βR) and radiative lifetime (τcal) for the 2H9/2→4I15/2, 4S3/2→4I15/2 and 4I13/2→4I15/2 emission transitions were determined using the JO intensity parameters. The absorption and emission cross-section values for the 4I13/2→4I15/2 emission band have been calculated using McCumbar theory and the Gain cross-section for the 4I13/2→4I15/2 emission transition also obtained. The upconversion emission mechanism have been studiedthrough various energy transfer processes and the intensity of the upconversion emission transitions are found to increase with the increase in Yb3+ ion concentration. The luminescence decay curves corresponding to the 4I13/2→4I15/2 transition of the Er3+/Yb3+ co-doped boro-tellurite glasses under 980nm excitation wavelength have also been studied and reported in the present work.