In this work, we have studied the spectroscopic and dynamic properties of the green(4S3/2→4I15/2)and blue(2P3/2→4I11/2)upconversions for a series ofEr3+dopedCa3Al2Ge3O12,induced by a red tunable laser excitation. The green emission is due to either an energy transfer involving two ions excited in the4I11/2multiplet or an excited state absorption from the4I13/2level, depending on whether the laser excitation wavelength is tuned on4I15/2→4F9/2or4I13/2→4F5/2.The blue emission mainly results from a three-step absorption process through the4I13/2and4S3/2multiplets. The temperature and concentration effects have been analyzed for the green and blue upconversions. ©1997 American Institute of Physics.