LASER-INDUCED FLUORESCENCE LINE NARROWING IN SM2+-DOPED FLUORIDE GLASS

Fluorescence line-narrowing experiments have been made for the Sm2+ ion in fluoride glass at 77 K under cw dye-laser excitation at various energies within the inhomogeneously broadened F-7(0)-5D0 and F-7(0)-5D1 absorption lines. The energies of the three Stark levels of the F-7(1) and 5D1 manifolds have been obtained as a function of the 5D0-F-7(0) energy separation. From the analysis of this result, it has been found that the site-to-site variations of the energies of these Stark levels can be explained well only by taking into account the J-mixing effect. The low-energy levels of the 4f(5)5d configuration lie in the vicinity of the 5D(J) states in this material. However, no effect of the crystal-field mixing of the 4f(5)5d states on the inhomogeneous distribution of the energies of the F-7(1) and 5D1 states has been observed. The origin of the unusually intense 5D0-F-7(0) transition in Sm2+ is also discussed.