  Metasurfaces are two-dimensional optical structures enabling complete control
of the amplitude, phase, and polarization of light. Unlike plasmonic
metasurfaces, planar silicon structures facilitate high transmission, low
losses and compatibility with existing semiconductor technologies. Here, we
report an experimental demonstration of high-efficiency polarization- sensitive
dielectric metasurfaces with full 2pi phase control in transmission mode at
telecommunication wavelengths. Such silicon metasurfaces are poised to enable a
versatile optical platform the realization of all-optical circuitry on a chip.
