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

Abstract Laser crystals of LiYF 4 (YLF) doped with 5–64 at.% of trivalent ytterbium ions (Yb 3+ ) were grown by a vertical Bridgman method. As crystal growth materials of YbF 3 and YF 3 including YOF impurities caused opaque crystal, the YOF reduction procedure using PbF 2 was essential before starting the crystal growth. We derived seven energy levels from the 2 F 7/2 and 2 F 5/2 manifolds of Yb 3+ :YLF by the crystal-field analysis from which we explain the observed polarized absorption and emission spectra. The intrinsic broad and complicated spectra of Yb 3+ :YLF are attributed to the strong coupling of the 4f electrons with lattice vibration of the crystal.