Phase control through Huygens' metasurfaces

We describe a dielectric Huygens' metasurface, operating in the visible spectrum, that can manipulate the phase of the transmitted light over a full 2π with high transmission efficiency. The metasurface is comprised of dielectric cylindrical nanoparticles embedded in a glass-like medium. The size of the nanoparticles and their separation are much smaller than the wavelength of visible light. From the metasurface, we construct a lens that focuses light to a diffraction limited spot size with high efficiency.