Spectroscopy of Yb3+ :CaF2: From isolated centers to clusters

Vincent Petit (1) , Patrice Camy (1) , Jean-Louis Doualan (1) , Xavier Portier (1) , Richard Moncorgé (1)

1 CIMAP - UMR 6252 - Centre de recherche sur les Ions, les MAtériaux et la Photonique

A detailed spectroscopic study of Yb3+ :CaF2 is made by using laser selective excitation, low-temperature time-resolved fluorescence, and Raman techniques. Three dominant types of Yb3+ isolated ion centers are identified at very low (0.03 at. %) dopant concentration: two of them with cubic and tetragonal symmetries and the third one not clearly identified but likely of trigonal symmetry. Fluorescence decays strongly differ from one site to another. The overall measured positions of the Stark sublevels of the 2F72 and 2F52 multiplets are satisfactorily explained by the crystal-field calculations. On the other hand, at higher dopant concentrations, only one dominant class of Yb3+ centers occurs which corresponds to some hexameric cluster in which the Yb3+ ions site in nearly tetragonal crystal-field environments and whose energy-level positions are discussed and compared with those previously reported in the literature.

Domaines: Optique [physics.optics]

Vincent Petit, Patrice Camy, Jean-Louis Doualan, Xavier Portier, Richard Moncorgé. Spectroscopy of Yb3+ :CaF2: From isolated centers to clusters. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2008, 78, pp.085131. ⟨cea-00348680⟩