High melting sesquioxides: crystal growth, spectroscopy, and laser experiments

Abstract Due to their high thermal conductivity the sesquioxides Sc 2 O 3 , Y 2 O 3 , and Lu 2 O 3 are interesting host materials for high power laser applications. Furthermore the strong crystal field of these host lattices is especially favourable for quasi-four-level systems such as the trivalent ytterbium ion. Several lanthanide-doped yttria, scandia, and lutetia crystals and a large boule with monocrystalline areas of a few cm 3 in volume have been prepared at our institute by the Bridgman method. The grown crystals exhibit promising features for laser operation. Here, we report on the spectroscopic characterization and first diode-pumped laser experiments with ytterbium-doped lutetia.