Composition-dependent optical transitions and 2.0 μm emission properties of Ho3+ in xGeO2-(80–x)TeO2-9.5ZnF2-10NaF-0.5Ho2O3 glasses

Ho3+ doped glasses with various compositions xGeO2-(80-x)TeO2-9.5ZnF2-10NaF-0.5Ho2O3 (x=0, 10, 20, 30, 40, 50, 60, 70 and 80) were prepared by a melt-quenching technique. The composition-dependent optical transition properties of Ho3+ were investigated in the framework of Judd-Ofelt theory. The emission cross sections for 5I7→5I8 transition of Ho3+ in these glasses were calculated according to McCumber theory, and their compositional dependence was discussed. A simple method was proposed in calculating the emission cross sections of 5I7→5I8 transition, and the calculation results were compared with those derived from McCumber theory. Finally, the optical gain coefficient spectra for 5I7→5I8 transition were also analyzed.