Indirect sensitization blue-upconversion wavelength vary in Tm3+/Yb3+ co-doped TeO2-TiO2-K2O glasses

The Tm3+/Yb3+ co-doped tellurite glasses with the base compositions (in mol%) 80TeO2-10K2O-(9.9 − x)TiO2-0.1Tm2O3-xYb2O3 (x = 0.1, 0.3, 0.5, 1.5 and 2.0) were prepared by the conventional melting method, their absorption spectra were performed, their indirect sensitization upconversion spectra were studied in detail. It was interesting to note that the luminescence peaks of indirect sensitization upconversion excited by 800 nm laser diode varied from 475 nm to 452 nm at first, then to 468 nm with x increasing, the corresponding luminescence intensity also increased with x. The processes of indirect sensitization upconversion were analyzed in detail. To our knowledge, no similar result has been reported before. The upconversion efficiency increased greatly, the efficiency of the sample when x = 2.0 was nearly 20-fold of that sample x = 0.1.