Design of Interactive Meta-Holographic Sensor Using Liquid Crystallinity

The arrays of subwavelength-scaled nanostructures on a surface, often called metasurfaces, have made advances in flat optics because of their potential to display programmable hologram and miniaturize optical components. As previous metasurface systems are passive, however, their practical applications have been impeded. Accordingly, recent efforts have focused on the realization of active metasurfaces that can autonomously sense a target trigger and switch homographic images. Nevertheless, the full potential of active metasurface system has yet to be realized due to the limitation of previous approaches, including limited design of nanostructures, complex fabrication process, and slow response.<br/>Here, we propose a simple and versatile approach to enable dynamically tunable metahologram systems by leveraging the optical anisotropic and stimuli-responsive nature of liquid crystals (LCs). We demonstrate the new class of active metahologram, a thin-layer of LCs integrated with multiplexing metasurface (LC-MS), to autonomously sense a programmed stimulus (e.g., electric field, temperature, pressure, toxic gas) and dynamically switch the holographic images [1,2]. These attribute provides insight into the rational design of interactive meta-hologram sensor/display that enable their full potential of multifunctional active devices.<br/><b>References</b><br/>[1] Kim, I.;, Kim, W.-S.; Kim, K.; Afnan, M.; Mehmood, M.; Badloe, T.; Kim, Y.; Gwak, J.; Lee, H.; Kim, Y.-K.*; Rho, J.* Holographic metasurface gas sensors for instantaneous visual alarms. <i>Science Advances</i>, <b>2021</b>, 7, eabe9943.<br/>[2] Kim, I.; Ansari, M. A.; Mehmood, M. Q.; Kim, W. -S.; Jang, J.; Zubair, M.; Kim, Y. -K.<b>*</b>; Rho, J.* Stimuli-responsive dynamic meta-holographic displays with designer liquid crystal modulator. <i>Advanced Materials</i>, <b>2020</b>, 32, 2004664.