Generation of scalar/vectorial vortex beams by using the plasmonic metasurfaces

Scalar and vector vortex beams are characterized of a helical wavefront but different polarized states, which result in different applications. In this paper, we design and fabricate a plasmonic metasurface based on the geometric phase principle. The designed metasurfaces are capable of generating a scalar vortex beam with a topological charge of ±2 and a vectorial vortex beam with a topological charge of ±1 in the near-infrared band. The experimental results are in good agreement with the simulation results, and our work provides a new idea for the development of a multivortex beam converter.