Dual-ended pumped high-power 915 nm Pr3+:LiYF4 laser and power scaling under energy levels cascade

•The highest power of the Pr3+:LiYF4 lasers at the 915 nm wavelength is achieved by using laser diodes dual-ended pumping to date.•To eliminate the laser power saturation phenomenon and further improve the output power, we propose a simple and effective method, namely laser energy levels cascade.•The output power, threshold, and slope efficiency of the laser in the cascade mechanism are theoretically predicted by establishing two different laser models. We reported a high-power 915 nm Pr3+:LiYF4 (Pr:YLF) laser dual-ended pumped by laser diodes (LDs). The maximum output power of the laser was 3.39 W with a slope efficiency of 19.8 %. The fluctuation range of the laser wavelength was less than 0.58 nm. As far as we know, this is the highest power at 915 nm for LD-pumped Pr:YLF lasers to date. To eliminate the power saturation phenomenon and further improve the laser output power, we proposed a simple and effective method, i.e., laser energy levels cascade. Based on the experimental data, we calculated the populations of 3P0 and 1G4 energy levels in Pr:YLF crystal during laser cascading and developed two different models to verify the feasibility of the laser cascade mechanism. Moreover, the laser cascade could be realized merely by designing the lens film without introducing other devices, which provided a simple and effective solution for developing high-performance lasers.