High power nanosecond optical vortex laser oscillation in mode-selection slab resonator

A method for generating high-power, millijoule level single pulse energy optical vortex laser using a mode-selection slab resonator is proposed and experimentally demonstrated. The optical resonator forms a stable cavity with just two mirrors and a Nd: YAG laser slab, which is both streamlined and reliable. The mode-selection involves the tilt control of cavity mirrors and the radius control of the circular aperture in favor of the donut-shaped LG₀₁ mode over others due to their different sensitivity to the resonator misalignment. By tuning the angle of the insert fused silica plate, nanosecond lasers in LG_0,+1, and LG_0,−1 modes are directly obtained with average power of 22.77 W and 21.85 W, and their pulse energies are 4.55 mJ and 4.37 mJ, respectively. The approach in this paper provides a concise solution for creating high-power vortex laser with slab resonator. Its potential for further power scaling holds promises for diverse applications, extending beyond industry manufacturing to fields like remote sensing, medical treatment, precision measurement, and scientific research.