The optical spectroscopy of LiGa(5)0(8):Ni(2+).

The optical spectroscopy of nickel-doped LiGa(5)0(8) is presented. Absorption and luminescence measurements taken over a wide temperature range indicate that the dopant nickel ion is doubly charged and occupies a site of near-octahedral symmetry. We observe a luminescence transition in the near-infrared which is assigned to the 3T(2)(3F)->3A(2)(3F) transition of the Ni (2+) ions. No visible luminescence is observed. Radiative decay times as a function of temperature have been measured to determine the presence and extent of nonradiative transitions in this system. The near-infrared luminescence appears to have a high quantum efficiency up to temperatures of around 350K above which nonradiative processes occur. The quantum efficiency and broad smooth shape of the luminescence makes this an interesting transition from the viewpoint of tunable laser action.