Undoped and Yb3+-doped Al2(WO4)3: crystal growth and spectroscopy of new optical materials

Pure and Yb 3+ -doped Al 2 (WO 4 ) 3 single crystals of good quality and purity were grown using the Bridgman-Stockbarger method. This is the first time that Al 3+ is substituted with big cations such as lanthanide ones. Undoped this compound has attractive properties as a non-linear X (3) material (ν 1 = 1049 cm -1 ). When doped with Yb 3+ , it also has interesting spectroscopic properties. Yb 3+ absorption, emission spectra and lifetime have been measured. The Yb 3 2 F 7/2 level splitting was found to be 856 cm (higher than Yb-YAG: 628), and its 2 F 5/2 excited level lifetime is 1.4 ms However, the Yb absorption cross-sections are weak.