Growth and spectroscopic characterization of Pb<Superscript>2+</Superscript>:CaF<Subscript>2</Subscript> crystals

CaF<Subscript>2</Subscript> crystals doped with various concentrations of PbF<Subscript>2</Subscript> (0.4, 0.5, 1 and 2 mol%) were grown in vacuum, in a shaped graphite furnace using the vertical Bridgman method. The optical absorption spectra reveal the four characteristic UV absorption bands (labeled A, B, C and D) of the Pb<Superscript>2+</Superscript> ions. As the PbF<Subscript>2</Subscript> concentration increases, the structure of the bands become clearly visible, that is characteristic for the ns <Superscript>2</Superscript> ions in various hosts. High intensity emission bands in the near UV spectral region have been observed. The dependence on the Pb<Superscript>2+</Superscript> concentration of the optical absorption and emission of the Pb<Superscript>2+</Superscript>:CaF<Subscript>2</Subscript> crystals were not reported before. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2012