Host dependent thermal stability and frequency upconversion of Er~(3+)-doped heavy metal oxyfluoride germanate glasses

摘要

The upconversion properties of Er~(3+)-doped heavy metal oxyfluoride germanate glasses under 975 nm excitation have been investigated. The intense green (551 and 529 nm) and relatively weak red (657 nm) emissions corresponding to the transitions ~4S_(3/2) →~4I_(15/2), ~2H_(11/2) → ~4I_(15/2) and ~4F_(9/2) → ~4I_(15/2), respectively, were simultaneously observed at room temperature. The content of PbF_2 has an important influence on the upconversion luminescence emission. With increasing content of PbF_2, the intensities of green (529 nm) and red (657 nm) emissions increase slightly, while the green emission (551 nm) increases markedly. These results suggest that PbF_2 has an influence on the green (551 nm) emission more than on the green (529 nm) and red (657 nm) emissions.