Enhanced 573 nm yellow emissions of Dy^sup 3+^ via Tb^sup 3+^ deactivation in Na^sub 2^Gd^sub 4^(MoO^sub 4^)^sub 7^ crystal

A Dy3+/Tb3+ co-doped Na2Gd4(MoO4)7 yellow laser crystal was successfully grown and analyzed. The use of Tb3+ codoping for enhancing the Dy3+:4F9/2→6H13/2 yellow emissions was investigated in the Na2Gd4(MoO4)7 crystal for the first time. In comparison to Dy3+ single-doped Na2Gd4(MoO4)7 crystal, the Dy3+/Tb3+ co-doped Na2Gd4(MoO4)7 crystal possessed a higher fluorescence branching ratio (80.2%), transition probability (3704 s−1), and fluorescence emission cross section (1.34×10−20 cm2) corresponding to the laser transition 4F9/2→6H13/2 of Dy3+. It was found that the introduced Tb3+ enhanced the 573 nm emission by depopulating the population of the laser lower level Dy3+: 6H13/2, and has little influence on the laser upper level Dy3+: 4F9/2 at the same time. These results suggest that Dy3+/Tb3+ co-doped Na2Gd4(MoO4)7 crystal may be an attractive host for developing solid state lasers at around 573 nm under a conventional 450 nm LD.