Gap-Surface Plasmon Metasurfaces For Structured Beams Generation

We design, fabricate and experimentally demonstrate a focused vector-beam (FVB) operating in reflection by designing gap-surface plasmon metasurfaces that enables efficient linear-polarization conversion and total phase control over the reflected light. The proof-of-concept fabricated sample efficiently generates FVBs in the wavelength range of 800-950nm with the averaged absolute efficiencies reaching as high as similar to 35% and similar to 34% for the radially-polarized and azimuthally-polarized beams, respectively.