Output characteristics of Pr:YAlO₃ and Pr:YAG lasers pumped by high-power GaN laser diodes

We investigated whether Pr:YAlO₃ and Pr:Y₃Al₅O₁₂ (YAG) can work as gain media for high-power visible lasers and replace trivalent praseodymium (Pr)-doped fluoride crystals, with particular focus on thermal loading resistivity. Pr:YAlO₃ exhibits a high laser gain at 747 nm, and we obtained a maximum output power of 1.2 W and a slope efficiency of 26.7% with high-power GaN laser diode pumping. Excited state absorption and large phonon energy hinder laser oscillation of Pr:YAG at room temperature. We obtained 616 nm laser oscillation of Pr:YAG at 40 K. Furthermore, we achieved a visible laser with Pr:YAG ceramics for the first time. The maximum output power is ∼30mW with a slope efficiency of ∼0.7%.