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

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 ^4S3/2→^4I15/2, ^2H11/2→^4 I15/2 and ^4F9/2 →^4I15/2, respectively, were simultaneously observed at room temperature. The content of PbF2 has an important influence on the upconversion luminescence emission. With increasing content of PbF2, 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 PbF2 has an influence on the green （551 nm） emission more than on the green （529 nm） and red （657 nm） emissions.

Host dependent thermal stability and frequency upconversion of Er3+-doped heavy metal xyfluoride germanate glasses

The upconversion properties of Er³⁺-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 \to ⁴I_15/2,²H_11/2\to ⁴I_15/2 and ⁴F_9/2 \to ⁴I_15/2, respectively, were simultaneously observed at room temperature. The content of PbF₂ has an important influence on the upconversion luminescence emission. With increasing content of PbF₂, 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 PbF₂ has an influence on the green (551\,nm) emission more than on the green (529\,nm) and red (657\,nm) emissions.