Blue cooperative luminescence in Yb3+-doped barium gallogermanate glass excited at 976 nm

摘要

The Yb3+-doped barium gallogermanate glass has been prepared via the conventional melt method. The absorption spectra, the near infrared emission spectra, the upconversion emission spectra and the differential scanning calorimetry have been measured. Bright blue upconversion emission centered at 476 nm has been observed under the 976 nm laser diode excitation at room temperature. The blue upconversion emission mechanism has been discussed on the blue emission intensity and the measured lifetime. The slope of the log-log plot of the blue emission intensity versus the pump power is equal to 1.98, and the blue luminescence decay time is half of the near infrared fluorescence decay time, confirming that the blue emission comes from Yb3+-Yb3+ pairs cooperative upconversion mechanism. The result of differential scanning calorimetry suggests that this type of glass is suitable as a potential candidate for fiber drawing.