Spectrally interleaved topologies using geometric phase metasurfaces

Deep-learning-assisted inverse design of dual-spin/frequency metasurface for quad-channel off-axis vortices multiplexing

“…As the proof of concept, quad-channel VBs carrying independent OAM and dual-frequency off-axis VVB generation are experimentally demonstrated in the microwave region. The proposed metasurface provides a pivotal degree of freedom of frequency/wavelength in addition to the conventional spin-decoupled method, 32 and further expands the channel capacity relative to the spectrally interleaved geometric phase metasufaces, 61 which may bring potential innovation to the improvement of channel capability in wireless/optical communication.…”

Multifunctional metasails for self-stabilized beam-riding and optical communication

“…Given the independence of these functionalities, two distinct phase discontinuity profiles should be imprinted across the metasail. A common approach to achieve this goal is to use shared aperture interleaved metasurfaces in which two or multiple sub-arrays are interspersed each of which is associated with a different phase function [34,35,36,37,38].…”

“…A common approach to achieve this goal is to use shared aperture interleaved metasurfaces, in which two or multiple sub-arrays are interspersed, each of which is associated with a different phase function. [34][35][36][37][38] Although previous demonstrations of metasails have relied on diffraction or resonant phase tuning to enable wavefront engineering, [20][21][22]31,32 the use of the geometric Pancharatnam-Berry (PB) phase shi seems to be a more natural choice, especially when it comes to a multifunctional design. The use of PB phase not only gives rise to a dispersionless phase discontinuity suitable for the broadband response required across the Doppler-broadened propulsion band for stable beam-riding, but also yields minimal crosstalk between the phase response of the interleaved subarrays in a multifunctional shared aperture platform owing to its non-resonant nature.…”

Terahertz Reconfigurable Metasurface for Dynamic Non-Diffractive Orbital Angular Momentum Beams using Vanadium Dioxide

“…Previous research has mainly focused on producing OAM beams based on metasurfaces without tunable metaparticles. The majority of these metasurfaces are aimed at producing an OAM beam with a particular l [15], [16]; realizing multichannel superpositions of OAM states with various l values [17], [18]; or generating OAM beams with different topological charges at different wavelengths [19], [20], input beam intensities [21] and polarization states [22]. However, in general, these metasurfaces are not tunable or reconfigurable, which inherently limits their practical impact.…”