Record size crystal growth and laser performance of Yb-doped lutetium oxide (Yb:Lu₂O₃) single crystal

The sesquioxide Lu2O3 possesses superior physical and chemical properties and emerges as a promising host material for high-power laser applications. However, Lu2O3 has an extremely high melting point, making it difficult to prepare large-size and high-quality crystals. In this paper, we report the growth of a Yb:Lu2O3 crystal with dimensions of phi 50.7 x 43.0 mm(3) using the temperature gradient technique (TGT) combined with the directional solidification technique. The full width at half maximum (FWHM) of the high-resolution X-ray rocking curve of the crystal was determined to be 58.76 arcsec. Additionally, the optical homogeneity root mean square (RMS) was 10(-5). The thermal properties, spectroscopic characterization, and continuous wave (CW) laser operation of Yb:Lu2O3 crystal were systematically studied. The results demonstrate the efficacy of the TGT as a novel approach for growing large-sized Lu2O3 crystals of exceptional quality.