Why so deep research on Yb3+-doped optical inorganic materials?

Abstract The state-of-art of Yb 3+ -doped inorganic materials will be presented due to strong interests in basics research and applied research. 4f 13 configuration will be illustrated by few examples such as optical transition assignments in the IR range, diode pumped-IR laser, figure-of-merit of laser crystals, concentration quenching studies, evidence of Yb 3+ pairs, the advance of Yb 3+ -doped cubic ceramics for laser sources, Yb 3+ as sensitizer of activator ions and Yb 3+ ion as structural probes of hosts. The last results analysed will concern charge transfer processes of Yb 3+ in oxides and the interests in luminescence.