Optical spectroscopy of BaY2F8:Dy3+

The optical spectra of the BaY 2 F 8 :Dy 3+ laser crystal have been investigated in the 5000–30 000 cm −1 range. The Judd–Ofelt parametrization scheme has been applied to the analysis of the room temperature absorption spectra. The calculated radiative lifetime of the 4 F 9/2 state is 1.48 ms. Decay curves of the visible emission have been measured as a function of the temperature for two different Dy 3+ concentrations (0.5 and 4.4%). In the case of the diluted crystal the emission profiles are single exponential with decay times consistent with the radiative lifetime. The decay curves of the concentrated crystal are not exponential and they obey the Inokuti–Hirayama model for energy transfer for an electric dipole–dipole interaction in the absence of diffusion among the donors. The emission cross section at 575 nm has been estimated using the integral β–τ method in order to assess the potentialities of this compound as a solid state laser material in the yellow region.