Tb3+→Ce3+ energy transfer in Tb3+:Ce3+:YAG single crystalsa)

An energy transfer from 5D3 and 5D4 levels of Tb3+ to 2D3/2 state of Ce3+ in Ce3+:Tb3+:YAG was studied using time resolved spectroscopy. It was found that the transfer from the Tb3+(5D3) level proceeds via (d–d) interaction and the critical distance is 18 Å. The transfer from Tb3+(5D4) state was consistent with the (d–d) interaction and with the critical distance of 15.4 Å, but could also be described in the framework of (d–q) interaction.