Watt-level and near diffraction-limited Pr³⁺-doped single-crystal fiber lasers

Using a CZ-grown a-cut Pr:YLF crystal as laser gain medium after processing it into crystal fiber, we have demon-strated real Pr3+-doped single-crystal fiber lasers for the first time to the best of our knowledge. This Pr3+ crystal fiber has absorbed up to 20.4 W of pump power, which is the highest absorbed power among Pr3+ lasers. For two representative laser emissions at about 639 nm and 607 nm, we have achieved maximum output powers of 5.45 W and 3.04 W, respectively. Output powers of the two lasers show very good linearities, which indicate that the present out-put powers are only limited by the available pump power. Both laser emissions have exhibited near diffraction-limited beam qualities. This proposal has provided a good and fea-sible route for the development of compact, high-power, and high-brightness all-solid-state Pr3+ visible lasers via crystal fiber.(c) 2023 Optica Publishing Group