GdCa4O(BO3)(3):Dy (GdCOB:Dy) crystal was grown using Czochralski (CZ) pulli
ng method. The polarized absorption and fluorescence spectra were measured
at room temperature. The energy levels of Dy3+ in the CdCOB:Dy crystal were
given based on the spectra. The characteristic parameters of the GdCOB:Dy
crystal were calculated using the Judd-Ofelt theory.