Generating colored holographic images by nonlinear processes

 |  SFBCeOPP  |  Nachrichten AG Zentgraf

Influencing the propagation of light plays a decisive role in all applications of light. Here, nanostructured surfaces, so-called Metasurfaces, enable custom-tailored light shaping by designing the properties of subwavelength scaled scatterers in a two-dimensional arrangement. Those particles can interact with light and alter its amplitude, phase, and even its frequency. In our recent publication entitled ‘Nonlinear Bicolor Holography Using Plasmonic Metasurfaces’ published in ACS Photonics, we show that two types of nanoparticle scatterers combined in one geometric metasurface can form a nonlinear colored hologram. By illuminating the metasurface with a near-infrared coherent beam, a colored holographic image appears in the visible regime. With our work, we show that the nonlinear signal can be adjusted depending on the incident light properties as well as the nanoparticles' resonance frequency. This approach demonstrates that multiple nonlinear processes can be combined into one metasurface to expand the application range of metasurface optics, for example in holographic color display applications, enhanced optical encryption schemes, and multiplexed optical data storage.

The present work is part of the joint project “Coupling between plasmonic excitations and intersubband transitions in nonlinear metasurfaces” of the groups of Prof. Zentgraf (Paderborn University) and Prof. Cinchetti (TU Dortmund) and is funded by the Deutsche Forschungsgemeinschaft (DFG) within the Collaborative Research Center TRR142 “Tailored Nonlinear Photonics”.

Nonlinear plasmonic metasurface for color holography. Rotation symmetric gold nano antennas are used to encode a holographic image based on the Pancharatnam–Berry phase. The position of the meta-atoms can be randomly distributed in a square lattice, while the rotation of each antenna is significant for the image encryption. The schematic illustration shows a nonlinear plasmonic metasurface, which can carry holographic information, for instance, a colored tree and house. If the metasurface is illuminated at its resonance frequency ω, the image is generated at frequencies 2ω and 3ω in Fourier space.