High-power single-longitudinal-mode visible Pr:YLF ring lasers

•Achieved visible single-longitudinal-mode Pr:YLF ring lasers using optical diode and F-P etalon.•Obtained watt-level single-longitudinal-mode SLM laser outputs for orange and red light.•Achieved the narrowest linewidth of Pr:YLF SLM output, 9.7 MHz for green, to our knowledge.•Presented detailed insights into linewidth variation with output power, validated using the Airy function. We present the development and characterization of high-power single-longitudinal-mode (SLM) Pr:YLF lasers across the visible spectrum using a ring cavity design integrated with an optical diode (OD) and Fabry-Perot etalons. Our study achieved notable single-frequency outputs at 639 nm (red), 604 nm, and 607 nm (orange), and 522 nm (green). Specifically, we obtained a maximum output of 1.4 W at 639 nm, while the orange lasers produced outputs of 435 mW at 604 nm and 1.03 W at 607 nm. The green laser achieved a maximum output of 313 mW at 522 nm. The narrowest linewidths recorded were 7.8 MHz for red, 9.4 MHz and 7.6 MHz for orange, and 9.7 MHz for green. These results demonstrate the feasibility of using a ring cavity combined with an F-P etalon to achieve high-power, narrow-linewidth SLM operation across a significant portion of the visible spectra, offering potential applications in precision spectroscopy, optical communications, and metrology.