Spectroscopic properties of Dy3+-doped NaGd(MoO4)2 crystal

• The polarized spectral properties of the Dy3+:NaGd(MoO4)2 crystal have been recorded.
• The crystal takes on large branching ratio for yellow emission.
• The emission cross-section of the crystal at 574 nm is much larger than that of Dy3+:LiNbO3.
• The crystal shows the potential of direct yellow laser generation.

A single crystal 1.85 at% Dy3+:NaGd(MoO4)2 was grown by the Czochralski method and spectroscopic properties of the crystal were investigated. Room temperature polarized absorption spectra were analyzed by the Judd–Ofelt theory. Then the intensity parameters, spontaneous transition probabilities, branching ratios, and radiative lifetimes of Dy3+ ions in the crystal were obtained. The peak polarized emission cross-sections for the 4F9/2 → 6H13/2 transition were calculated to be 1.62 × 10−20 and 1.35 × 10−20 cm2 for π and σ polarizations respectively by the Füchtbauer–Ladenburg equation. The fluorescence decay curve and quantum efficiency of the 4F9/2 multiplet were measured to be 156 μs and 74%, respectively. The experimental results show that the Dy3+:NaGd(MoO4)2 crystal can be pumped directly by commercially available 450 nm blue laser diodes and may be a promising yellow laser material.