Growth, refined structural and spectroscopic characteristics of Tm3+-doped NaGd(WO4)2 single crystals

The details of Tm3+-doped NaGd(WO4)2 single-crystal growth are discussed, the results of precise investigations of its structural and spectroscopic characteristics, as well as the analysis of cross-relaxation process of Tm3+ ions (3H4→3F4, 3H6→3F4) in this crystal are presented. Based on the Judd-Ofelt theory, three intensity parameters, spontaneous emission probabilities, fluorescence branching ratios and fluorescence quantum efficiency from 3H4 and 3F4 levels were refined.