摘要:ABSTRACT: Preparation and optical characterization of dysprosium gadolinium oxalate (DGO), dysprosium praseodymium oxalate (DPO) and gadolinium praseodymium oxalate (GPO) single crystals are reported. The crystals were grown using silica gel technique, by the controlled reaction of rare earth nitrates with oxalic acid. Crystals were characterized using X-ray powder diffraction and optical absorption studies. Radiative transition probability, fluorescence branching ratio and radiative lifetime of Dy3+ and Pr3+in the crystals are evaluated by the parameterization of the absorption spectrum using Judd-Ofelt theory. Keywords: oxalate crystals, rare earths, X-ray diffraction, and Judd-Ofelt theory.