Multi‐Channel Image Encryption Based on an All‐Dielectric Metasurface Incorporating Near‐Field Nanoprinting and Far‐Field Holography

Abstract

Metasurfaces that can efficiently control the light‐field characteristics have shown many advantages in ultra‐compact, high‐resolution, and high‐concealment optical imaging such as nanoprinting and holography. The development of metasurfaces with multiple functions operating at multiple wavelengths can promote the progress of optical imaging with high information storage and encryption densities. Here, an all‐dielectric metasurface is proposed for multi‐channel image encryption in the near field by controlling the amplitude distribution based on Marius’ law and for holographic imaging in the far field by controlling the phase distribution based on the Pancharatnam–Berry phase. This metasurface can realize the pattern imaging of 12 channels by independently regulating the three‐wavelength channel and different polarization modes. The metasurface achieves independent control of the amplitude, phase, polarization, and wavelength of the incident light wave, improving the storage capacity of information and its encryption security level. The proposed multichannel metasurface provides an effective solution for high‐capacity optical encryption and information storage applications.

Four-channel holographic metasurface based on frequency-angle multiplexing

“…Among these, metasurface holography is one of the most promising imaging techniques due to its characteristics of ultra-compactness, high resolution, and large viewing angles, which enable high-quality image reconstruction [13]. In addition, the metasurface holographic technology can also utilize controllable optical parameters such as amplitude [14], phase [15,16], polarization state [17,18], wavelength [19,20], orbital angular momentum [21], and incident angle [22] to achieve multidimensional multiplexing, thereby improving the efficiency of information transmission.…”