Design of Optical Security Platform with Oblique Helicoidal Liquid Crystals

Abstract

As an increase of interest on personal information, encrypting data with high security has received a lot of attention. Optical security platforms are considered as a strong candidate for promising security systems owing to using infinite degrees of freedom light. Here, we suggest a simple approach for high security of optical security platform via incorporating oblique helicoidal liquid crystal (ChOH) that controls wavelength of light into multi-band metasurface which modulates properties of incident light by controlling configurations of embedded nanostructures. Specifically, we design the ChOH to reflect a certain wavelength of incident light only when specific electric field and temperature are applied. In addition, the multi-band metasurface displays holographic images when target wavelengths of light are introduced. Therefore, the encrypted wavelength information on metasurface is decoded as holographic images only upon precise electric field and temperature. Since the configurations of light and nanostructures are infinite, our approach provides high security as well as the ability to be protected from computational decoding.