Electron paramagnetic resonance enhanced crystal field analysis for low point-group symmetry systems: C 2v sites in Sm 3+ :CaF 2 /SrF 2 .

We present a comprehensive spectroscopic study of C-2v point-group symmetry sites in Sm3+:CaF2/SrF2 codoped with either NaF or LiF. Data includes electron paramagnetic resonance measurements of Zeeman and hyperfine interactions for the ground state, as well as site-selective excitation and fluorescence spectroscopy up to the (4)G(5/2) multiplet. Inclusion of the EPR data allowed us to determine unique crystal-field parameters. The parameters provide information about the geometry of the sites and the nature of the interactions between the Sm3+ dopant and the alkaline earth co-dopant.