Optical absorption and luminescence study of cobalt-doped magnesium aluminosilicate glass ceramics

Linear and nonlinear optical properties of cobalt-doped magnesium aluminosilicate transparent glass ceramics that were prepared under different conditions have been studied. It has been shown that absorption and luminescence spectra and absorption bleaching of these glass ceramics are defined mainly by tetrahedrally coordinated Co2+ ions located in magnesium aluminum spinel nanocrystals. The lifetimes of the T-4(1)(F-4) and T-4(2)(F-4) excited states of the tetrahedral Co2+ ions were found to be in the ranges 25-40 and 120-450 ns, respectively, depending on the Co concentration. (C) 2002 Optical Society of America.