UP-CONVERTED ENERGY-TRANSFER FROM ER3-CRYSTAL FIBERS( TO CR3+ IN LINBO3 SINGLE)

In this paper, site occupations of Er3+ and Cr3+ in LiNbO3 (LNO) singl e crystal fibers are discussed. A pairing structure of Er-Cr tends to provide a geometric advantage for cooperative processes, Efficient up- converted energy transfer from Er to Cr tvas observed by pumping the I -4(9/2) state in the near infrared. Downward energy transfer from Cr3 to Er3+ was studied by pumping the T-4(2) State of Cr3+. The up-conve rted and the downward energy transfer can be used to develop diode-pum ped tunable lasers or to sensitize 1.5 mu m Er lasers, respectively.