Al2O3 color center lasing in near infrared at 300 K

Two investigated color center types are luminescent in the near IR in sapphire crystals. These color centers have no-phonon lines of 0.755 and 0.914 microns, radiative decay times of 94 and 65 ns, absorption cross-sections of 0.57 x 10 to the -17th and 1.8 x 10 to the -17th per sq cm, respectively, and no temperature luminescence quenching is observed at 300 K. Optical pumped laser action with both CC types was obtained. The laser emission was continuously tunable over the ranges of 0.75-0.95 and 0.96-1.15 microns, and laser efficiencies were 1 and 16 percent, respectively.