Lutetium oxide single-crystal fibers for laser applications

The growth of single-crystal optical fibers of Yb-doped Lu₂O₃ is reported. The quality of the fibers is characterized by single-crystal X-ray diffraction, SEM imaging, thermal conductivity and Raman spectroscopy. Preliminary cladding experiments using a high-temperature hydrothermal method are described. The single pass amplification of Yb:Lu₂O₃ is measured up to 6mW, and lasing is demonstrated up to 300mW with a slope efficiency of 2.6%.