Quantum efficiencies of near-infrared emission from Ni2+-doped glass-ceramics

A systematic method to evaluate potentials of Ni2+-doped transparent glass-ceramics as a new broadband optical gain media is presented. At first, near-infrared emission of various ceramics were investigated to explore the suitable crystalline phase to be grown in the glass-ceramics. The quantum efficiency of Ni2+ near-infrared emission estimated by the Struck-Fonger analysis was higher than 95% for spinel-type structure gallate crystals MgGa2O4 and LiGa5O8 at room temperature. Transparent glass-ceramics containing Ni2+:LiGa5O8 could be prepared and the quantum efficiency for the glass-ceramics was measured to be about 10%. This value shows a potential of Ni-doped transparent glass-ceramics as a broadband gain media.