Structural-Color Encrypted Meta-Holography: Sb2S3-Driven Tri-Channel Switching between Near- and Far-Field Light Manipulation

Abstract Over the past decades, there has been significant progress in imaging technology based on metasurfaces. The amount of optical information that can be stored on metasurface has increased continuously, evolving from static imaging to dynamic imaging. In this article, a three-channel dynamic switching imaging metasurface based on the phase-change material Sb 2 S 3 has been proposed, where three images are captured at the interface of the metasurface, the near field (Fresnel region), and the far field (Fraunhofer region), respectively. Thanks to the significant differences in their optical properties between the crystalline and amorphous states of the Sb 2 S 3 material, dynamic imaging and hiding capabilities have been demonstrated by temperature-controlled switching of the material state. By employing the Adam optimization algorithm to systematically tune the parameters of Sb 2 S 3 meta-atom, coupled with rigorous validation through finite-difference time-domain simulations, we successfully demonstrate tri-channel dynamic imaging with low crosstalk, high resolution, and exceptional contrast ratio. This design provides an efficient platform for dynamic optical display, information encryption, and multifunctional integration with promising prospects in image display, information security, and optical storage fields.