Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 59: Plasmonics and Nanooptics

O 59.5: Poster

Dienstag, 21. März 2017, 18:30–20:30, P2-OG1

Fabrication and Characterization of Photonic Metasurfaces — •Alexander Faßbender, Felix Bleckmann, and Stefan Linden — Physikalisches Institut, Rheinische Friedrich-Wilhelms Univerität Bonn, Nußallee 12, D-53115 Bonn, Germany

Photonic metasurfaces can be used to locally control the phase of incoming electromagnetic waves by scattering the wave from the sub-wavelength building blocks of the metasurface. In combination with the Generalized Snell’s law this allows to nearly arbitrarily control the refraction at such surfaces. Depending on the exact structure of the used metasurface one can construct various optical elements, e.g., lenses and holograms.
Here, we want to demonstrate a metasurface that generates an optical vortex. For that purpose, we fabricate an antenna array using electron beam lithography. We employ gold antennas with a length of 200 nm to modify the properties of a circular polarized wave at 750 nm wavelength. More specific, we control the locally induced phase of light with the opposite helicity by rotating each antenna by a certain angle relatively to a reference axis. To achieve a radial phase gradient, necessary to generate an optical vortex, the orientation of the antennas rotates by π per turn. Using an interferometer we plan to demonstrate that our photonic metasurface generates an optical vortex exhibiting the characteristic spiral phase distribution.