Topological transformation of vortex beams using cylindrical lens

The topological transformation of vortex beams using cylindrical lens is experimentally and numerically demonstrated. The intensity distributions and phase structures of vortex beams with different topological charges were analyzed after the transformation by a cylindrical lens, which were generated using the computing generated holographic method. The results show that the transformation of the cylindrical lens results in the sign change of the topological charges of the vortex beams. In addition, the higher order vortex beams decay into a beam with multiple singularities with charge-one. These observations were analyzed based on the linear superposition of higher order laser modes and Gouy phase delay. Finally, the experiment results were verified by the numerical simulations.