Independent Manipulations of Transmitting and Receiving Channels by Nonreciprocal Programmable Metasurface

Abstract

The electromagnetic (EM) beam manipulations such as spatial scanning have always been the focus in information science and technology. Generally, the transmitting and receiving (T/R) beams of the same aperture should be coincident due to the reciprocal theory, and hence, more flexible controls of the spatial information are limited accordingly. Here, we propose a new approach to achieve independent controls of beam scanning in spatial T/R channels based on one aperture made by a nonreciprocal programmable metasurface. The meta-atom is designed to have independent propagation chains for T/R waves by introducing dual-direction power amplifiers (PAs) as the isolators for one-way transparency. A programmable phase shifter with a 360°coverage is loaded with the PA device in the transmitting or receiving chain to realize independent beam scanning in the T/R channels. A prototype of the proposed metasurface is fabricated, and independent beam scanning in the T/R channels is directly acquired with good performance in our measurements. In addition, a proof of concept of integrated sensing and auxiliary communications is accomplished to verify the validity of the presented method.

Synergy between AI and Optical Metasurfaces: A Critical Overview of Recent Advances

“…Tunable and reconfigurable nonreciprocal structures are among the hot topics in the field of AI-metasurface synergy. Some examples include manipulation with transmitting and receiving channels in nonreciprocal surfaces that has been dealt with in 2024 [168], nonreciprocal magnetic metasurfaces for phase modulation in 2023 [169] and many more.…”

Simultaneous Circular Dichroism and Wavefront Manipulation with Generalized Pancharatnam–Berry Phase Metasurfaces

“…Metasurfaces are the two-dimensional equivalent of metamaterials, possessing the remarkable ability to flexibly manipulate the amplitude, phase, and polarization of electromagnetic waves by periodically arranging subwavelength structures, which opens a new era of digital optics. − Many exotic phenomena and applications have been observed with metasurfaces, such as the compact spectrometer, , optical computing, , optical biosensing, , quantum entanglement, , asymmetric photonic spin–orbit interactions, − achromatic and ultrawide-angle lenses, − and simultaneous circular dichroism and wavefront manipulation. − Various structures, such as the quasi-split-ring resonator, helical surface arrays, and chiral stepped nanoaperture, have been proposed. However, these methods increase the complexity of design and fabrication due to the requirement of structures to break the n -fold ( n > 2) rotational and mirror symmetries or vertical symmetry.…”