High Efficiency Ultrathin Transmissive Metasurfaces

Abstract Metasurfaces offer unprecedented freedom to manipulate electromagnetic waves at deeply subwavelength scales. However, realizing a highly efficient metasurface, yet simple enough to conceptualize, design, and fabricate, is a challenging task. In this paper, a novel approach is proposed for designing meta‐atoms which can achieve full phase control in the range 0–2 π with high efficiency in the transmission mode. In particular, a bilayer meta‐atom is designed, exploiting nearly perfect polarization conversion of the two orthogonal transmissions, whose transmission efficiency reaches as high as 85%. The transmission phase control in the circular polarization basis is achieved with the axial rotation of the proposed meta‐atom based on Pancharatnam–Berry phase principle. These meta‐atoms are then wielded to construct metasurfaces for generating vortex beams carrying orbital angular momentum. The conversion efficiency as high as 75% and a transmission efficiency of 55% are achieved for the realized metasurfaces.