Spectroscopic properties of newly flux grown and highly Yb3+-doped cubic RE2O3 (RE=Y, Gd, Lu) laser crystals

We have developed laser grade and highly Yb3+-doped cubic rare-earth sesquioxides (RE2O3, RE = Y, Gd, Lu) single crystals by means of a newly designed high-temperature solution growth method which gives them spectroscopic properties different from those obtained by high-temperature solidification methods. Absorption and emission cross sections, visible anti-Stokes emission, fluorescence decays of the new cubic Gd2O3:Yb3+ single crystals are presented and compared to those of Y2O3:Yb3+ and Lu2O3:Yb3+ crystals. The case of cubic Gd2O3:Yb3+ is particularly interesting since its basic spectroscopic properties have never been detailed and we were capable of achieving Yb-doping level as high as 20%.