Correction of vortex laser beam in a closed-loop adaptive system with bimorph mirror

The phase correction of a vortex laser beam is undertaken in the closed-loop adaptive system including a Hartmann–Shack wavefront sensor with singular reconstruction technique and a bimorph piezoceramic mirror. After correction the vortex doughnutlike beam is focused into a beam with bright axial spot that considerably increases the Strehl ratio and optical system resolution. Since the phase break cannot be exactly reproduced on the flexible mirror surface, off-axis vortices appear in the far field at the beam periphery.