Preparation and up-conversion luminescence properties of Er: YbAG and Er: YAG single crystals

High quality optical single crystals of cubic Yb 2.96 Er 0.04 Al 5 O 12 and Y 2.96 Er 0.04 Al 5 O 12 were successfully prepared using the OFZ method. The 980 nm photon absorption intensity by Yb 2.96 Er 0.04 Al 5 O 12 crystal is much larger than that in Y 2.96 Er 0.04 Al 5 O 12 crystal, the transmission of Yb 2.96 Er 0.04 Al 5 O 12 crystal is lower than that of Y 2.96 Er 0.04 Al 5 O 12 crystal, because the density of Yb 2.96 Er 0.04 Al 5 O 12 single crystal (6.604 g/cm 3 ) is larger than that of Y 2.96 Er 0.04 Al 5 O 12 single crystal (4.529 g/cm 3 ). The up-conversion luminescence spectra of the crystals excited by 980 nm laser show several distinct groups of emission peaks at ∼544 and ∼556 nm, as well as ∼650 and ∼667 nm. The peak intensities of the up-conversion luminescence spectrum for the Yb 2.96 Er 0.04 Al 5 O 12 crystal were much higher than those for the Y 2.96 Er 0.04 Al 5 O 12 crystal. Overall, the results of the present study suggest that Yb 2.96 Er 0.04 Al 5 O 12 single crystal may have advantages over Y 2.96 Er 0.04 Al 5 O 12 single crystal for luminescence in solid-state lasers.