Generating High-Purity Directive Circularly Polarized Beams From Conformal Anisotropic Holographic Metasurfaces

Abstract

Using anisotropic holographic metasurfaces to transform the creeping waves into circularly polarized (CP) beams has initiated the quest for tangible applications in different disciplines. However, the present designs are only limited to the planar impedance surfaces with rare studies concerning the linear-to-circular polarization converting holographic metasurface over the conformal platforms. In this article, we demonstrate the perfect transformation of linearly polarized (LP) surface waves into CP waves through cylindrical anisotropic holographic metasurfaces consisting of gradient H-shaped slits etched on the periodic circular patches. Especially, the linear-to-circular polarization conversion rate can always maintain a very high level for the beam synthesis no matter how the curvature of the metasurface changes, and such high-purity CP beams also demonstrate very good quality of steerable characteristics over conformal surfaces. Our approach, using anisotropic holographic metasurfaces to transform the creeping waves into high-purity CP beams, should pave the way for more advanced functional meta-device designs over the nonplanar impedance surfaces.