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Multi-photon-excited thermal-correlated green and red upconversion (UC) emissions have been quantified in H o 3+ / Y b 3+ co-doped fluotellurite (BZLFT) glass phosphor under the 978 nm laser excitation. The temperature dependence of the fluorescence intensity ratio (FIR) originated from UC emissions bands centered at 550 nm and 661 nm has been verified in the range of 303-543 K. The net emission photon numbers of 5 F 4 + 5 S 2 → 5 I 8 and 5 F 5 → 5 I 8 transition emissions are up to 40.08×10 12 and 68.51×10 12 c p s in the 0.4 w t . % H o 2 O 3 -0.4 w t . % Y b 2 O 3 co-doped BZLFT case under the 6.95 W / m m 2 laser power density. Furthermore, the quantum yield (QY) and luminous flux are determined to be dependent on pumping power. When the excitation power increases 874 mW, the QY values for 550 nm and 661 nm emissions are as high as 0.94×10 -5 and 1.60×10 -5 . In addition, the high photon producing efficiency is conducive to ensuring high feedback to thermosensitive performance. The temperature thermal sensor can be manipulated steadily in medium temperature range, and the relative sensitivity reaches 0.4 % K -1 at 303 K, which is 1 order of magnitude larger than those in several rare-earth-doped materials. Efficient photon conversion ability and high temperature sensitivity indicate that the rare-earth-ion-doped fluotellurite material has a prospective application in the construction of optical temperature sensors based on the FIR technique allowing for self-referenced temperature determination.

Intense multi-peak red fluorescence and effective near-infrared (NIR) ultra-broadband emission have been observed in Pr 3+ doped ion-exchangeable aluminum germanate (NMAG) glasses. The maximum emission cross section for P 0 3→F 2 3 red emission is up to 100.58×10 -21   cm 2 , and the NIR emission corresponding to D 2 1→G 4 1 transition possesses a full-width at half-maximum (FWHM) of 210 nm. Although the obvious cross-relaxation (CR) process at high concentration causes a decrease of the quantum efficiency, the CR broadens the spectral FWHM effectively from another perspective. The admirable red fluorescence trace and the NIR single-mode transmission confirm that Pr 3+ doped NMAG glass planar waveguides can support the generation of visible fluorescence and the amplification of infrared signal. For a waveguide channel ion-exchanged in molten KNO 3 for 2 h, the single-mode field diameters at 1.55 μm are identified to be 10.4 μm in the horizontal direction and 6.5 μm in the vertical direction, implying an acceptable overlap with a standard single-mode fiber. Effective red fluorescence and broad NIR emission demonstrate that Pr 3+ doped NMAG glasses are a promising substrate in developing irradiative luminescence sources and ultra-broadband waveguide amplifiers, especially operating at the entire S-, C-, and L- bands.