Metamaterial Huygens´ surfaces from microwave to optical frequencies

Huygens´ surfaces are two-dimensional metamaterials (metasurfaces) that impart arbitrary phase shifts on light passing through them. These reflectionless surfaces provide new beam shaping, steering, and focusing capabilities. They are realized with spatially varying, two-dimensional arrays of polarizable particles that provide both electric and magnetic polarization currents. If the surface is anisotropic, polarization control such as linear-to-circular polarizers are also possible. Huygens´ surfaces at microwave, mm-wave, and optical frequencies are demonstrated.