Metasurface Enabled Multi‐Target and Multi‐Wavelength Diffraction Neural Networks

Laser & Photonics Review, Год журнала: 2024, Номер unknown

Опубликована: Сен. 3, 2024

Abstract Benefiting from low power consumption and high processing speed, there is a growing interest in diffraction neural networks (DNNs), which are typically showcased with 3D printing devices, leading to large volumes, costs, levels of integration. Metasurfaces can desirably manipulate wavefronts electromagnetic waves, providing compact platform for mimicking DNNs novel functions. Although multi‐wavelength multi‐target recognition provides richer more detailed understanding complex environments, existing architectures primarily trained classify single target at specific wavelength. A metasurface approach proposed design multiplexed that multiple targets spatial sequences across various wavelengths channels. To realize multi‐task processing, the dielectric designed based on phase wavelength multiplexing, integrate different tasks such as operating distinct classifying diverse targets. The efficacy this method exemplified through numerical simulation experimental demonstration recognizing two wavelengths, wavelength, dual wavelengths. This enables DNNs, opening new window develop massively parallel versatile artificial intelligence systems.

Язык: Английский

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An Ultrathin, Fast‐Response, Large‐Scale Liquid‐Crystal‐Facilitated Multi‐Functional Reconfigurable Metasurface for Comprehensive Wavefront Modulation

Advanced Materials, Год журнала: 2024, Номер 36(26)

Опубликована: Апрель 8, 2024

The rapid advancement of prevailing communication/sensing technologies necessitates cost-effective millimeter-wave arrays equipped with a massive number phase-shifting cells to perform complicated beamforming tasks. Conventional approaches employing semiconductor switch/varactor components or tunable materials encounter obstacles such as quantization loss, high cost, complexity, and limited adaptability for realizing large-scale arrays. Here, low-cost, ultrathin, fast-response, solution relying on metasurface concepts combined together liquid crystal (LC) requiring layer thickness only 5 µm is reported. Rather than immersing resonant structures in LCs, joint material-circuit-based strategy devised, via integrating deep-subwavelength-thick LCs into slow-wave structures, achieve constitutive metacells continuous phase shifting stable reflectivity. An LC-facilitated reconfigurable sub-system containing more 2300 realized its unprecedented comprehensive wavefront manipulation capacity validated through various functions, including beam focusing/steering, vortex beams, holograms, demonstrating milli-second-level function-switching speed. proposed methodology offers paradigm shift modulating electromagnetic waves non-resonating broadband fashion fast-response low-cost properties by exploiting functionalized LC-enabled metasurfaces. Moreover, this extremely agile metasurface-enabled antenna technology will facilitate transformative impact systems empower new possibilities engineering diffractive wave calculation/inference.

Язык: Английский

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Physics‐Informed Inverse Design of Programmable Metasurfaces

Advanced Science, Год журнала: 2024, Номер unknown

Опубликована: Сен. 5, 2024

Abstract Emerging reconfigurable metasurfaces offer various possibilities for programmatically manipulating electromagnetic waves across spatial, spectral, and temporal domains, showcasing great potential enhancing terahertz applications. However, they are hindered by limited tunability, particularly evident in relatively small phase tuning over 270°, due to the design constraints with time‐intensive forward methodologies. Here, a multi‐bit programmable metasurface is demonstrated capable of beam steering facilitated developed physics‐informed inverse (PIID) approach. Through integrating modified coupled mode theory (MCMT) into residual neural networks, PIID algorithm not only significantly increases accuracy compared conventional networks but also elucidates intricate physical relations between geometry modes. Without decreasing reflection intensity, method achieves enhanced as large 300°. Additionally, inverse‐designed experimentally validated, which adaptable 1‐bit, 2‐bit, tri‐state coding schemes, yielding deflection angle up 68° broadened coverage. The demonstration provides promising pathway rapidly exploring advanced devices, potentially impact on communication imaging technologies.

Язык: Английский

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Directional Phase and Polarization Manipulation Using Janus Metasurfaces

Advanced Science, Год журнала: 2024, Номер 11(38)

Опубликована: Авг. 9, 2024

Abstract Janus metasurfaces, exemplifying two‐faced 2D metamaterials, have shown unprecedented capabilities in asymmetrically manipulating the wavefront of electromagnetic waves both forward and backward propagating directions, enabling novel applications asymmetric information processing, security, signal multiplexing. However, current metasurfaces only allow for directional phase manipulation, hindering their broader application potential. Here, study proposes a versatile metasurface platform that can directionally control polarization terahertz by integrating functionalities half‐wave plates, quarter‐wave metallic gratings within cascaded structure. As proof‐of‐principle, experimentally demonstrates capable independent simultaneous over polarization, showcasing propagation direction‐encoded focusing conversion. Moreover, focused points are utilized with distinct states advanced direction‐ polarization‐sensitive detection imaging. This unique strategy direction‐dependent versatility opens new avenues designing ultra‐compact devices significant implications imaging, encryption, data storage.

Язык: Английский

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Liquid Crystal Metasurface for On‐Demand Terahertz Beam Forming Over 110° Field‐Of‐View

Laser & Photonics Review, Год журнала: 2024, Номер 18(9)

Опубликована: Апрель 15, 2024

Abstract The terahertz spectral region, which bridges between electronics and optics, is poised to play an important role in the development of transformative wireless communication imaging systems with unprecedented functionality. Currently, a major challenge technology develop high‐performance beam‐forming devices that can dynamically shape radiation flexible manner. Existing have limited coding bits, field‐of‐view, beam gain. Here, reconfigurable liquid crystal‐integrated metasurface experimentally demonstrated, each unit cell being independently addressable. has 260° continuous phase tuning range crystal layer thickness only 1% free‐space wavelength. wave diffracted from be steered toward wide directions shown, covering record‐large 110° field‐of‐view peak gain 25 dBi. also features low power consumption sub‐second switching time. Furthermore, formation multiple beams direction ratio adjustable on demand. proposed possesses compelling prospects for future applications.

Язык: Английский

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Meta‐Device for Field‐of‐View Tunability via Adaptive Optical Spatial Differentiation

Advanced Science, Год журнала: 2025, Номер unknown

Опубликована: Янв. 13, 2025

Optical edge detection is a crucial optical analog computing method in fundamental artificial intelligence, machine vision, and image recognition, owing to its advantages of parallel processing, high speed, low energy consumption. Field-of-view-tunable particularly significant for detecting broader range objects, enhancing both practicality flexibility. In this work, novel approach-adaptive spatial differentiation proposed field-of-view-tunable detection. This improves the ability acquire information facilitates over wider angular range. The adaptive meta-device relies on two core components: dielectric metasurface liquid prism. shown function as highly efficient (≈85%) isotropic differentiator, operating across entire visible spectrum (400 700 nm) within wide-angle object space, expanding up 4.5 times original field view. scheme presents new opportunities efficient, flexible, high-capacity integrated data processing imaging devices. And simultaneously provides architecture next generation wide field-of-view phase contrast microscopy.

Язык: Английский

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Electrically Active Terahertz Liquid‐Crystal Metasurface for Polarization Vortex Beam Switching

Laser & Photonics Review, Год журнала: 2024, Номер 18(7)

Опубликована: Март 12, 2024

Abstract Polarized vortex waves have attracted widespread attention in investigations of light–matter interactions and the augmentation information capacity owing to their distinctive characteristics. Nevertheless, reconfigurable generation vector beams, especially at terahertz (THz) frequencies, remains challenging. In this study, a tunable THz polarization beam generator based on liquid‐crystal metasurface is proposed. A unit cell featuring linear selectivity developed. general methodology for designing metasurfaces generate customized patterns introduced. Furthermore, electrically polarized cylinder beams experimentally demonstrated. The findings study can open up opportunities wireless communication super‐resolution imaging applications.

Язык: Английский

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Enabling Beam-Scanning Antenna Technologies for Terahertz Wireless Systems: A Review

Fundamental Research, Год журнала: 2024, Номер 5(2), С. 556 - 570

Опубликована: Ноя. 12, 2024

Due to the exponentially growing global mobile data of wireless communications evolving from 5 G 6 in recent years, research activities leveraging terahertz (THz) waves obtain larger channel capacities have shown an ever-increasing pace and reached unprecedented height than before. Historically, past few decades already witnessed much progress THz generation detection technologies, which been recognized for a long time as bottleneck preventing being tamed by human beings. However, importance developing advanced components such antennas, transmission lines, filters, power amplimers, etc., constitute basic building blocks system, should not be overlooked sake exploiting spectra future communications, sensing imaging applications. While producing scannable highly-directive antenna beam proves indispensable period microwaves, significance functionality is more critical era, considering that intractable challenges severity free-space propagation losses, susceptibility atmospheric environments, unavailability efficient signal sources. This article structured under this background, dedicated reviewing several enabling beam-scanning concepts, structures, architectures developed systems. Specifically, we divide these solutions into four groups based on different mechanisms, i.e., mechanical motion, phased array, frequency beam-scanning, reconfigurable metasurfaces.

Язык: Английский

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A dual-band programmable metasurface for terahertz beam steering

Applied Physics Letters, Год журнала: 2025, Номер 126(19)

Опубликована: Май 12, 2025

Terahertz programmable metasurfaces hold significant promise for next-generation communications due to their capability steer electromagnetic waves. However, most existing terahertz operate at only a single frequency, leaving much of the vast spectrum underutilized. In this study, we introduce “butterfly” dual-band metasurface, integrated with liquid crystals, designed efficient beam steering. By applying bias voltages, metasurface achieves phase change nearly 270° two distinct frequencies, ∼400 and ∼700 GHz. Our experimental results demonstrate that butterfly is compatible both binary ternary coding schemes these remarkably enhancing beam-steering performance expanding spatial coverage. This advancement in technology marks step forward harnessing full potential spectrum, opening another pathway broadband communication imaging applications.

Язык: Английский

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Reconfigurable Intelligent Metasurface Technology for Terahertz Communication

Springer proceedings in physics, Год журнала: 2025, Номер unknown, С. 608 - 623

Опубликована: Янв. 1, 2025

Язык: Английский

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