Design of Security Platform via Holographic Metasurface with Oblique Helicoidal Liquid Crystals

Abstract

Metasurfaces (MSs) with sub-wavelength scale of nanostructures have an ability to respond to the properties of incident light (e.g., wavelength, polarization, incident angle) and provide a corresponding programmed optical signal that are predetermined by configuration of nanostructures. Because the configurations of light and nanostructures have the infinite degrees of freedom, therefore, the metasurfaces have been considered as promising security platform that does not allow computational decryption . Here, we propose the simple and versatile design of high security platform via wavelength responsive MS integrated with the layer of oblique helicoidal liquid crystals (LCs). Specifically, we design MS to display holographic images only when target wavelengths of light are exposed. The integrated LC layers are programmed to reflect the target wavelengths under the specific electric field and temperature. Consequently, we demonstrate our security platform to show the encrypted holographic image only when the programmed electric field and temperature are applied. This work was supported by the NRF (2021R1A4A1030944, 2021R1A2C2095010, 2022M3C1A3081312).