High-power and efficient vortex Nd:YVO4 laser using annular pumping

Optical vortex lasers that carry orbital angular momentum are of great significance for many applications. A high-power and efficient continuous-wave vortex Nd:YVO4 laser at 1064 nm was demonstrated with annular pumping based on an axicon. The high-quality LG(01) vortex beams with maximum output power up to 6.25 W was achieved under the absorbed pump power of 14.4 W, corresponding to an optical conversion efficiency of 43.4% and a slope efficiency of 44.8%, respectively. Controlling the wavefront handedness of the LG(01) beam was simply achieved by carefully adjusting the output coupler and the window inserted in the resonator. This study shows that annular pumping based on an axicon would have great potential in the development of high-power vortex solid-state lasers with simple and compact resonator structure.