Single Pixel Imaging Key for Holographic Encryption Based on Spatial Multiplexing Metasurface

Abstract

Compared with the traditional holographic technology, metasurface holography is a promising technology due to the large field angle and high spatial resolution. Thanks to the precise control of phase, amplitude, polarization and so on, metasurface holography provides a flexible platform for light modulation, optical encryption and so on. Besides, the process of image reconstruction by single pixel imaging is similar to a form of encoding and decoding, which is realized by calculating the correlation between a series of modulation patterns and their corresponding intensity signals. In this work, an optical encryption scheme is proposed based on spatial multiplexing metasurface, which depends on the combination of holographic technology and single pixel imaging technology. In the encryption scheme, the image transmitted by single pixel imaging based on metasurface is used as the addressing key of holography. Besides, illuminating different positions of the metasurface can generate different holographic reconstructed images, and there is 50% information overlapped between adjacent sub‐holograms. This work makes use of the spatial multiplexing property of metasurface, which can complete different functions, paving the way for the application in the field of optical imaging encryption and information security.

Recent Advances and Prospects of Optical Metasurfaces

“…In addition to efficient wavefront modulations ,,, and diverse holographic multiplexing, ,,− inverse design ,− has been developed to rapidly meet the increasing demands of metasurface design. In addition, intelligent algorithms promote novel optical detection technologies, such as single-pixel imaging (Figure a), , hyperspectral imaging, ,,, and all-optical diffractive deep neural network. ,− …”

“…With the aid of an intelligent algorithm, a single metasurface can simultaneously implement multiple functions, ,,,,,− which can significantly simplify the design, assembly, and operation of optical systems. Intelligent optical processing − and detection technologies − are constantly emerging. Supported by advanced fabrication, metasurfaces with larger diameters and more complex structures are being developed to achieve better performance and more complex functions.…”

Holographic-assisted multiplexing optical metasurfaces

“…We also proposed a holographic encryption method based on combination of single pixel imaging and multiplexing holography [10]. The schematic is shown in Figure 4.…”

“…To increase the transmittance, the aperture size of nanohole is optimized. And for the spatial multiplexing holographic metasurface [10], to increase the security, we introduced the overlapping multiplexing, where two neighbor holograms share half area. And only the illumination aims at the correct area, the image can be reconstructed successfully, and here are the simulation results.…”

Continuous‐Spectrum–Polarization Recombinant Optical Encryption with a Dielectric Metasurface

“…[34,35] Moreover, a combination of single-pixel imaging and holography based on spatial multiplexing metasurfaces has been demonstrated for optical encryption, which further increases the capacity and DoFs of information transmission. [36] Theoretically, the information capacity of optical encryption is determined by the DoFs of metasurfaces light control. Great achievements have been made to continuously expand the number of DoFs, and the ultimate eight DoFs in Jones matrix has been realized by bilayer metasurface.…”