Metasurface holographic image projection based on mathematical properties of Fourier transform

Abstract

Fourier transform, mapping the information in one domain to its reciprocal space, is of fundamental significance in real-time and parallel processing of massive data for sound and image manipulation. As a powerful platform of high-efficiency wave control, Huygens’ metasurface may offer to bridge the electromagnetic signal processing and analog Fourier transform at the hardware level and with remarkably improved performance. We here demonstrate a Huygens’ metasurface hologram, where the image pattern can be self-rotated or projected in free space by modulating the phase distribution based on the rotational invariance, time-shifting and scaling properties of Fourier transform. Our proof-of-concept experiment shows high-efficiency imaging operation in accordance with theoretical predictions, validating the proposed scheme as an ideal way to perform largely parallel spatial-domain mathematical operations in the analog domain using electromagnetic fields.

Domain multiplexed computer-generated holography by embedded wavevector filtering algorithm

“…We believe this new algorithm can find applications in other iteration algorithms for phase retrieval as well. Other types of wavevector filtering, such as high-pass, band-reject and band-pass, are also expected to incorporate into the CGH for implementing various image processing tasks [35,36].…”

Meta-optics for spatial optical analog computing

“…Extending the applicability of mathematical operations to the microwave wavelengths could take advantage of the ease of fabrication and simpler characterization of artificial structures [133]. To showcase the effectiveness of quantum analog behaviors in wave-based signal processing, microwave metamaterials were utilized as quantum searching simulators [134].…”

Dual‐Polarized Tri‐Channel Encrypted Holography Based on Geometric Phase Metasurface

“…[4][5][6] There are several basic approaches to realize the abrupt phase changes for the metasurface construction: plasma metasurface composed of nano antennas [7] for linearly polarized incident waves, geometric phase also named as Pancharatnam-Berry (P-B) phase metasurface for circularly polarized incident waves, [4,8,9] and Huygens' metasurface which can manipulate the scattered co-polarized component under linearly polarized incident illuminations. [10][11][12][13][14][15] In addition, 1-bit phase-coding metasurface has crucial applications in holographic imaging and beamforming. [16,17] Traditional gradient index metamaterials and lenses allow manipulating the transmitted phase of the co-polarized component by the propagation phase through the variation of unit cell structure parameters, [18] which is further adopted in metasurface design.…”