4f2 to 4f5d excited state absorption in Pr3+-doped crystals

We first report one photon classical spectroscopy of Pr3+-doped LiLuF4 single crystals which leads to the energy level diagram for Pr3+ levels in this host and to the D-1(2) and P-3(0) emitting level lifetimes. Then, excited state absorption (ESA) spectra from these metastable levels to 4f5d states are presented and the ESA cross-sections are in the order of 10(-18) cm(2). Subsequently, such upconversion excitation into the 4f5d states of Pr3+ is used to generate the broad band 4f5d to 4f(2) UV fluorescence. Moreover, an energy transfer from Pr3+ 4f5d states to Ce3+ 5d states is clearly identified. (C) Elsevier Science B.V. All rights reserved.