2024 | Jooohon Kim, Jun-Hyung Im, Sunae So, Yeongseon Choi, Hyun Jung Kang, Bogyu Lim, Minjae Lee, Young-Ki Kim, and Junsuk Rho
This study presents a dynamic hyperspectral holography system enabled by inverse-designed metasurfaces combined with oblique helicoidal cholesteric liquid crystals (CH_OH). The metasurface, designed using inverse design, allows encoding of ten independent holographic images at different wavelengths. The CH_OH, which has an oblique helicoidal structure, provides precise spectral modulation with a narrow bandwidth and wide tunable range, enabling dynamic switching of multicolor holography. The system demonstrates simultaneous spatial and spectral tunability, allowing for high information capacity and dynamic control of the holographic images through changes in electric field (E) and temperature (T). The CH_OH cell acts as a tunable wavelength modulator, reflecting specific wavelengths of light to the metasurface, resulting in multicolor metallograms with combinations of E and T. The results show that the system can achieve near-zero crosstalk between holographic images due to the high information density. The study also demonstrates an optical secret-sharing platform, where a specific combination of E and T is required to decrypt the holographic images. The system offers a high-security platform with potential applications in security and optical encryption. The proposed method provides a simple and generalizable approach for designing interactive metasurfaces with tunable optical properties. The study highlights the potential of combining metasurfaces with liquid crystals for advanced optical applications.This study presents a dynamic hyperspectral holography system enabled by inverse-designed metasurfaces combined with oblique helicoidal cholesteric liquid crystals (CH_OH). The metasurface, designed using inverse design, allows encoding of ten independent holographic images at different wavelengths. The CH_OH, which has an oblique helicoidal structure, provides precise spectral modulation with a narrow bandwidth and wide tunable range, enabling dynamic switching of multicolor holography. The system demonstrates simultaneous spatial and spectral tunability, allowing for high information capacity and dynamic control of the holographic images through changes in electric field (E) and temperature (T). The CH_OH cell acts as a tunable wavelength modulator, reflecting specific wavelengths of light to the metasurface, resulting in multicolor metallograms with combinations of E and T. The results show that the system can achieve near-zero crosstalk between holographic images due to the high information density. The study also demonstrates an optical secret-sharing platform, where a specific combination of E and T is required to decrypt the holographic images. The system offers a high-security platform with potential applications in security and optical encryption. The proposed method provides a simple and generalizable approach for designing interactive metasurfaces with tunable optical properties. The study highlights the potential of combining metasurfaces with liquid crystals for advanced optical applications.