Transparent 45SiO(2)-25Al(2)O(3)-5CaO-10NaF-15CaF(2) glass ceramics doped with different levels of Er3+ were prepared. The spherical CaF2 nanocrystals with 10-20 nm in size were verified to be homogeneously embedded among the glassy matrix. Room temperature absorption and emission spectra corresponding to I-4(13/2) <-> I-4(15/2) transitions of Er3+ ions in precursor glasses and glass ceramics, respectively had been measured. For glass ceramics, with increasing of Er3+ content from 0.1 to 2.0 mol%, the FWHM values of the emission bands increased from 42 to 71 nm; meanwhile, the lifetime of I-4(13/2) level slightly reduced. However, both the values of FWHM and lifetime were larger than those of precursor glasses due to the change of ligand field of Er3+ ions. (c) 2005 Elsevier Ltd. All rights reserved.