Tunable lasing due to the4T2–4A2electronic–vibrational transition in Cr3+ions in BeAl6O10

Tunable radiation in the 0.79–0.87 μm range was obtained at room temperature in a new active medium BeAl 6 O 10 :Cr 3+ . The energy gap between the 2 E and 4 T 2 levels (~ 236 cm −1 ) and the activation energy E a ≈ 1667 cm −1 were determined. Absorption, luminescence, and excitation spectra were determined and an investigation was made of the temperature dependence of the excited-state relaxation time of Cr 3+ ions in BeAl 6 O 10 (τ lum ≈ 13 × 10 −6 s at 300 K).