COMPOSITIONAL DEPENDENCE OF ER3-CONVERSION LUMINESCENCE IN MF-LIF-ZRF4, GLASSES (M- ALKALI-METALS)( UP)

Compositional variation of the Er3+ upconversion luminescence in the Z rF4-based fluoride glasses was examined with the glass-modifying alkal i-fluoride in 21.25MF . 21.25LiF . 52.5ZrF(4) . 5ErF(3) glasses (M = L i, Na, K, Rb or Cs). Upconversion luminescence of the glasses with 800 nm excitation gave emission bands around 410, 525, 550 and 660 nm. Em ission intensities of these bands changed remarkably, depending on the MF species. An explanation for the observed alkali-fluoride dependenc e is based on the deviation from inversion symmetry in the F- coordina tion around Er3+ and the multiphonon decay rate in the glasses which w ere evaluated from the fluorescence and excitation spectra of Eu3+ ion s in glasses substituted Eu for Er.