Аннотация:Phase relationships in the Er:YbxGd1-xAl3(BO3)4-K2Mo3O10-B2O3-(Gd,Er,Yb)2O3 (x=0-0.2, Er-1at.%) system were studied in the temperature range from 1150 to 900оС. Multicomponent melts of 55 mol.%K2Mo3O10 - 45 mol.% B2O3 (I) and 55 mol.% K2Mo3O10 - 40 mol.% B2O3 - 5 mol.% (Gd,Er,Yb)2O3 (II) were suggested as reasonable fluxes for high-temperature solution growth of (Yb3+,Er3+):GdAl3(BO3)4 single crystals. Yb0.15Gd0.85Al3(BO3)4 solubility in the complex flux of II composition has been found as varying from 17 to 9.5 mol.% with decreasing temperature in the interval of 1000-800oC. As a result, (Er,Yb):GdAB single crystals with high optical quality and sizes up to 20×10×10 mm were grown on dipped “point” seeds. Absorption and stimulated emission spectra, emission lifetimes, and efficiencies of energy transfer from Yb3+ to Er3+ ions were determined. Highly efficient continuous-wave diode-pumped laser operation of (Er,Yb):GdAl3(BO3)4 crystal was realized.