Spectroscopic properties of Yb doped YLF grown by a vertical Bridgman method

Laser crystals of LiYF4 (YLF) doped with 5-64 at.% of trivalent ytterbium ions (Yb3+) were grown by a vertical Bridgman method. As crystal growth materials of YbF3 and YF3 including YOF impurities caused opaque crystal, the YOF reduction procedure using PbF2 was essential before starting the crystal growth. We derived seven energy levels from the F-2(7/2) and F-2(5/2) manifolds of Yb3+:YLF by the crystal-field analysis from which we explain the observed polarized absorption and emission spectra. The intrinsic broad and complicated spectra of Yb3+:YLF are attributed to the strong coupling of the 4f electrons with lattice vibration of the crystal. (c) 2005 Published by Elsevier B.V.