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O: Fachverband Oberflächenphysik
O 77: Poster: Plasmonics and Nanooptics
O 77.24: Poster
Wednesday, March 14, 2018, 18:15–20:30, Poster A
Ultrathin metasurfaces for nonlinear optical image encoding — •Felicitas Walter1, Guixin Li2, and Thomas Zentgraf1 — 1Department of Physics, University of Paderborn, D-33098, Germany — 2Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
In this project we demonstrate that an ultrathin nonlinear photonic metasurface, consisting of meta-atoms with three-fold rotational symmetry, can be used to hide optical images under illumination with a fundamental wave. However, the hidden image can be read out from second harmonic generation (SHG) waves. This is achieved by controlling the destructive and constructive interferences of SHG waves from two neighboring meta-atoms. In addition, we apply this concept to obtain grey-scale SHG imaging. Nonlinear metasurfaces based on space variant optical interference open new avenues for multi-level image encryption, anti-counterfeiting and background free image reconstruction.