Optical properties of transparent alkali gallium silicate glass-ceramics containing Ni²⁺-doped β-Ga₂O₃ nanocrystals

Broadband near-infrared (IR) luminescence in transparent alkali gallium silicate glass-ceramics containing Ni²⁺-doped β-Ga₂O₃ nanocrystals was observed. This broadband emission could be attributed to the ³T_2g (³F) → ³A_2g (³F) transition of octahedral Ni²⁺ ions in glass-ceramics. The full width at half-maximum (FWHM) of the near-IR luminescence and fluorescent lifetime of the glass-ceramic doped with 0.10 mol% NiO were 260 nm and ∼1220 μs, respectively. It is expected that transparent Ni²⁺-doped β-Ga₂O₃ glass-ceramics with this broad near-IR emission and long fluorescent lifetime have potential applications as super-broadband optical amplification media.