Benefit of Tb3+ ions to the spectral properties of Dy3+/Tb3+:CaYAlO4 crystal for use in yellow laser

Single crystals of Dy3+ single-doped and Dy3+/Tb3+ co-doped CaYAlO4 are grown and analyzed. In comparison to Dy3+:CaYAlO4, the absorption cross sections around 453 nm and emission cross section at 582 nm acquired a growth after the incorporation of Tb3+. The fluorescence lifetimes of Dy3+:4F9/2 upper and Dy3+:6H13/2 lower laser levels for 582 yellow emission fall from 0.293 ms to 0.070 ms–0.285 ms and 0.018 ms, respectively. The fluorescence branching ratios of yellow emission at 582 nm are 49.2% and 50.733% for Dy3+:CaYAlO4 and Dy3+/Tb3+:CaYAlO4 crystals, respectively. Deactivation effect of Tb3+ ions as well as the energy transfer mechanism in Dy3+/Tb3+:CaYAlO4 crystal are discussed in detail, and the temperature dependent spectra of the two crystals are also studied as well. Those results indicate that the introduction of deactivation ion Tb3+ can be beneficial for achieving an enhanced yellow emission in Dy3+/Tb3+:CaYAlO4.