Luminescence at 1.53 μm for a new Er3+-doped transparent oxyfluoride glass ceramic

Transparent 45SiO225Al2O35CaO10NaF15CaF2 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 4I13/2 ↔ 4I15/2 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 4I13/2 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.