Reconfigurable All-dielectric Transmission Lens for Vortex Beam Generation

In this paper, a novel design for vortex beam generation is proposed by utilizing phase-gradient all-dielectric metamaterials. The pluggable element of proposed design is able to provide a full transmission–phase covering the range of $2 \pi$ together with a high transmission efficiency. The elements corresponding to each value of phase are encoded to 360 modules. Thus, designed phase modules can be judiciously arranged to generate vortex beams carrying orbital angular momentum with different modes. Full-wave simulations validate the spiral-shaped phase fronts of the vortex beam. The proposed lens paves the way for the applications of vortex beam.