Abstract

The sesquioxide of Yttrium is subject of interest to the fields of laser physics and spectroscopy since the early sixties. It exhibits a thermal conductivity that is higher than that of the well established laser host material Y₃AI₅O₁₂ (YAG). Similarity high thermal conductivities can also be found in the isostructural scandia (Sc₂O₃) and lutetia (Lu₂O₃). The thermal conductivities range between 12.5 W/mK in lutetia and 16.5 W/mK in scandia, measured at 50 C . Undoped YAG shows a thermal conductivity of 11 W/mK measured under the same conditions. This property makes the sesquioxides promising host materials for rare-earth based laser systems, especially for high power applications. Furthermore the sesquioxides exhibit a strong crystal field splitting which is favourable for quasi four level systems, e. g. Ytterbium lasers. Another advantage are the very low phonon energies, which reduce the non radiative losses in all laser systems.

© 2000 IEEE