Beam alignment based on the imaging properties of the spatial filter by controlling the deformable mirror in a high power laser

Deformable mirror placed in the front-end is widely used for wavefront correction in high power solid-state lasers. However, the laser beam is usually partly blocked by the spatial filter pinhole when the deformable mirror surface is improper. In this paper, this beam alignment problem is solved based on the imaging properties of the spatial filter by controling the defocusing value of the deformable mirror surface. Experimental results show that the spatial filter pinhole is passed through successfully and a relatively complete laser beam nearfield is achieved after beam alignment in the output of the laser system.