Enhanced 3 μm luminescence properties based on effective energy transfer Yb 3+ : 2 F 5/2 →Dy 3+ : 6 H 5/2 in fluoaluminate glass modified by TeO 2

Enhanced 3 μm luminescence of Dy3+ based on the effective process of Yb3+:F5/22→Dy3+:H5/26 with a higher energy transfer coefficient of 7.36×10−39  cm6/s in fluoaluminate glass modified by TeO2 was obtained. The energy transfer efficiency from Yb3+ to Dy3+ in Dy3+/Yb3+ codoped glass was as high as 80%, indicating the effective energy transfer of Yb3+. The higher temperature of the glass transition (Tg) and larger characteristic temperatures (ΔT,Kgl) revealed better thermal properties of the prepared glasses compared with the traditional fluoaluminate glasses, which is of great benefit to fiber drawing. The lower hydroxyl content (15.7 ppm) indicated better fluorescence properties of the glass. It was noted that the longer lifetime of 572 μs and higher emission cross section of 5.22×10−21  cm2 along with the bandwidth of 245 nm around 3 μm proved potential applications in mid-IR laser materials of the present glass.