.Optics Communications 159 1999 221–224 De-excitation mechanisms of BaLiF:Co2q crystals3

4 4. 2qThe de-excitation mechanisms from the T F level for a promising new vibronic laser material, BaLiF:Co2 3 .emission centered at 1588 nm, FWHMs426 nm, are reported. At low temperatures, the decay time is on average equal to .580 ms, decreasing very rapidly above 80 K t s1 ms. This decrease is due to multiphonon processes from the excitedRT 4 4. 4 4.vibronic level T F to the highly excited vibronic fundamental level T F promoted by the vibrational modes E and2 1 g T of the BaLiF crystal. The decay time dependence on the temperature was fitted according to the Mott–Seitz model,2g 3 presenting a good agreement. The following parameters were determined: radiative lifetime, t s580 ms, nonradiative