Broadband 1-1.7 µm emission in Ni2+/Yb3+/Er3+-doped silica-gallo-germanate glass-ceramics and their optical fiber

This paper presents a novel glass-ceramics material and its fiber co-doped with Yb³⁺/Ni²⁺/Er³⁺ fabricated by the rod-in-tube method. By successive heat-treatment of glasses, it was possible to embed Ni²⁺ ions into γ-Ga2O3 nanocrystals, resulting in broadband emission in the range of 1.0-1.7 µm. Measured luminescence decay times suggested possible energy transfer from Yb³⁺ to Ni²⁺ and Er³⁺ ions. For fabricated optical fiber co-doped with Yb³⁺/Ni²⁺/Er³⁺ ions, we obtained a crystal environment of Ni²⁺ ions during the fiber drawing process without further heat-treatment of the fiber. The widest obtained (3 dB and 10 dB bands) for the fabricated optical fiber were equal to 52 nm and 495 nm, respectively (λexc = 940 nm).