Upconversion emissions of Yb3+/Er3+-codoped germanate-tellurite glasses have been investigated upon the excitation of 980 nm laser diode (LD). It is found that up- conversion luminescence intensities significantly inc...Upconversion emissions of Yb3+/Er3+-codoped germanate-tellurite glasses have been investigated upon the excitation of 980 nm laser diode (LD). It is found that up- conversion luminescence intensities significantly increase with the increasing size of alkali metal ions. Raman spectra show that the maximum phonon energies (MPE) of glass hosts are unchanged with the replacement of alkali metal oxides, indicating that MPE is not the reason for the increase of upconversion fluorescence intensities. The analysis of the non-radiative transition of Er3+ demonstrates that the de- crease of the maximum energy phonon density is the main reason for the enhanced fluorescence intensities.展开更多
文摘Upconversion emissions of Yb3+/Er3+-codoped germanate-tellurite glasses have been investigated upon the excitation of 980 nm laser diode (LD). It is found that up- conversion luminescence intensities significantly increase with the increasing size of alkali metal ions. Raman spectra show that the maximum phonon energies (MPE) of glass hosts are unchanged with the replacement of alkali metal oxides, indicating that MPE is not the reason for the increase of upconversion fluorescence intensities. The analysis of the non-radiative transition of Er3+ demonstrates that the de- crease of the maximum energy phonon density is the main reason for the enhanced fluorescence intensities.
