Actively Q-switched self-frequency-doubled Yb:YCOB green laser with output power of a dozen watts

A diode laser (LD) end-pumped acousto-optic Q switched self-frequency-doubled (SFD) Yb:YCa4O(BO3)3 (Yb:YCOB) pulsed green laser was realized for the first time (to our knowledge), with a maximum average output power of 11.6 W and an optical conversion efficiency of 30.0% from the LD to SFD lasers. The wavelength of the SFD lasers was controlled to be 507 nm for improving quantum efficiency up to 96% and reducing thermal effects. The repetition rates ranged from 20 to 500 kHz, and the maximum pulse energy was 312.0 mu J with a peak power of 4.78 kW at a repetition rate of 20 kHz. This work represents the highest output power in the SFD pulsed lasers and provides an efficient and compact way to generate high-power pulsed green lasers that should have important applications in many aspects, such as ultraviolet (UV) laser generation, laser display, and medical, military, and scientific research. (c) 2023 Optica Publishing Group