Rare-earth-ion-doped sesquioxide laser materials

In this contribution the spectroscopic properties of the Yb-doped sesquioxides like absorption, emission, and lifetime data will be discussed with special consideration of concentration quenching effects since high doping concentrations are necessary for high power thin-disc lasers. Furthermore, recent results of cw-and mode-locked laser experiments with TiSa-and diode-laser pumping will be reported.