Plasmonic Holographic Metasurfaces for Generation of Vector Optical Beams

In this paper, a 2-D anisotropic metasurface for generating an azimuthally polarized beam is structured with a patterned metallic layer, which is composed of a fork hologram and periodically aligned sector-shaped antennas in annular circles. The polarization state of the light is tailed due to the plasmonic effect of the antenna unit, which behaves like a single nanopolarizer. The induced Pancharatnam-Berry phase will be compensated by the fork hologram. Such a metasurface in a large pattern size of 27 by 27 μwith fine nanoaperture slits in a resolution of 200 nm is successfully fabricated. Numerical simulations of the single antenna element and the whole holographic structure are performed and coincide with experimental results well. An azimuthally polarized vector beam with a ring-shaped intensity distribution is generated by the metasurface from an incident circularly polarized light, which will serve as flat optical components in optical trapping, super-resolution imaging, and other application fields.