Continuous-wave Pr³⁺:BaY₂F₈ and Pr³⁺:LiYF₄ lasers in the cyan-blue spectral region

We report on the first, to the best of our knowledge, continuous-wave quasi three-level lasers emitting in the cyan-blue spectral range in praseodymium-doped crystalline materials. Applying Pr(3+):BaY2F8 as an active medium, up to 201 mW of output power at 495 nm could be obtained with a slope efficiency of 27% under pumping with an optically pumped semiconductor laser (2ω-OPSL) at 480 nm. In the same pumping scheme using Pr(3+):LiYF4, output powers up to 70 mW were realized at 491 and 500 nm, respectively. With Pr(3+):BaY2F8, diode-pumped laser operation with up to 11% slope efficiency and 44 mW output power was also achieved. In the latter case, detailed investigations on the temperature dependency of the laser output were conducted. Moreover, comparative experiments were carried out for the first time, to the best of our knowledge, with green-emitting Pr(3+):BaY2F8 lasers at 524 and 553 nm both under diode and 2ω-OPSL excitation.