Transparent silicate glass-ceramics embedding Ni-doped nanocrystals

摘要

Recent progress in the development of transparent silicate glass-ceramics embedding Ni-doped nanocrystals as broadband gain media is reviewed. At first, optical properties such as the peak positions, wavelengths lifetimes and quantum efficiencies of the near-infrared emission of nickel-doped oxide crystals are overviewed. The quantum efficiencies of the near-infrared emission of nickel-doped LiGa5O8 and MgGa2O4 were as high as ~1 even at room temperature. Thus these materials are promising candidate crystals to be precipitated in glass-ceramics. Crystallization process of Li2O-Ga2O3-SiO2-NiO (LGSN) glass was investigated in detail. Transparent glass-ceramics in which only Ni2+:LiGa5O8 was contained as crystalline phases have been successfully prepared from the glass by heat-treatment. The glass-ceramics exhibited broad near-infrared emission around 1300 nm and the quantum efficiency was about 10 %. The figure of merit as laser transition of the emission was comparable to that of rare-earth doped glasses used in optical fiber amplifiers. LGSN transparent glass-ceramics is a promising candidate material for broadband optical fiber amplifiers and tunable lasers.