Optical, structural and luminescence properties of oxyfluoride phosphate glasses and glass-ceramics doped with Yb3+

Abstract The impact of Al 2 O 3 and Y 2 O 3 addition on the structure, Yb 3+ luminescence and crystallization is investigated for glasses in the P 2 O 5 -SrO-Na 2 O system. Although the addition of Al 2 O 3 and Y 2 O 3 leads to a more connected phosphate network as evidenced using IR and Raman spectroscopies and increases the glass transition temperature, it does not affect strongly the site of the Yb 3+ . The addition of Al 2 O 3 and Y 2 O 3 slightly decreases the rate of the glass crystallization. Surface crystallization occurs upon heat treatment. Crystallization was confirmed by the presence of sharp peaks in the XRD patterns of the glasses. Independently of the glass composition, different crystalline phases precipitate in the glasses upon heat treatment. The precipitation of the Na 1 O 7 P 2 Yb 1 crystal phase leads to an increase of the excited state 2 F 5/2 lifetime of Yb 3+ and also of the bandwidth of the Yb 3+ emission band centered at 1 μm.