SPECTROSCOPY AND EXCITED-STATE ABSORPTION OF NI2-DOPED MGAL2O4()

Luminescence, ground-state and excited-state absorption and lifetime m easurements on Ni2+-doped MgAl2O4 were performed. Excited-state absorp tion bands at 1700 nm in the near infrared and at 750 and 580 nm in th e visible region due to the transitions from the T-3(2) (F-3) metastab le stale to the T-3(1)(F-3), T-1(2)(D-1), and T-3(1)(P-3) states were observed and ESA cross sections were determined. The T-3(2)-T-3(1)(F-3 ) ESA band overlaps with the emission band and prevents lasing of Ni2:MgAl2O4 at room temperature.