Upconversion photon quantification in Tm3+/Yb3+ doped aluminum germanate glasses for waveguide-typed irradiation light sources

Upconversion (UC) fluorescence photons have been quantified precisely in Tm3+/Yb3+ doped waveguide-adaptive aluminum germanate glasses under the excitation of 975 nm laser with different power density. The quantum yield (QY) for intense near-infrared (NIR), weak red and efficient blue multi-photon UC emissions of Tm3+ is identified as a positive correlation with laser power density, and the increasing tendency of the QY for three-photon fluorescence is extremely severe. The absolute QY values for 477 nm blue and 806 nm NIR UC emissions are derived to be 1.43 × 10−4 and 36.11 × 10−4, respectively, when the excitation power density is set to 1482 W/cm2. The macroscopic quantization of UC photons in Tm3+/Yb3+ doped aluminum germanate glasses provides a valuable reference in developing integrated waveguide-typed irradiation light sources.