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Littérature scientifique sur le sujet « Directional metasurfaces »

Auteur : Grafiati

Publié le 29 mars 2025

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Articles de revues sur le sujet "Directional metasurfaces"

Zhang, Ranran, Qiuling Zhao, Xia Wang, Kai Ming Lau, Tsz Kit Yung, Jensen Li et Wing Yim Tam. « Controlling asymmetric transmission phase in planar chiral metasurfaces ». Nanophotonics 11, n^o 3 (22 décembre 2021) : 495–505. http://dx.doi.org/10.1515/nanoph-2021-0558.

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Abstract Metasurfaces with ultrathin artificial structures have attracted much attention because of their unprecedented capability in light manipulations. The recent development of metasurfaces with controllable responses opens up new opportunities in various applications. Moreover, metasurfaces composed of twisted chiral structures can generate asymmetric responses for opposite incidence, leading to more degrees of freedom in wave detections and controls. However, most past studies had focused on the amplitude responses, not to mention using bi-directional phase responses, in the characterization and light manipulation of chiral metasurfaces. Here, we report a birefringent interference approach to achieve a controllable asymmetric bi-directional transmission phase from planar chiral metasurface by tuning the orientation of the metasurface with respect to the optical axis of an add-on birefringent substrate. To demonstrate our approach, we fabricate planar Au sawtooth nanoarray metasurface and measure the asymmetric transmission phase of the metasurface placed on a birefringent sapphire crystal slab. The Au sawtooth metasurface-sapphire system exhibits large oscillatory behavior for the asymmetric transmission phase with the tuning parameter. We confirm our experimental results by Jones matrix calculations using data obtained from full-wave simulations for the metasurface. Our approach in the characterization and light manipulation of metasurfaces with controllable responses is simple and nondestructive, enabling new functionalities and potential applications in optical communication, imaging, and remote sensing.

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Aigner, Andreas, Stefan Maier et Haoran Ren. « Topological-Insulator-Based Gap-Surface Plasmon Metasurfaces ». Photonics 8, n^o 2 (4 février 2021) : 40. http://dx.doi.org/10.3390/photonics8020040.

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Topological insulators (TIs) have unique highly conducting symmetry-protected surface states while the bulk is insulating, making them attractive for various applications in condensed matter physics. Recently, topological insulator materials have been tentatively applied for both near- and far-field wavefront manipulation of electromagnetic waves, yielding superior plasmonic properties in the ultraviolet (UV)-to-visible wavelength range. However, previous reports have only demonstrated inefficient wavefront control based on binary metasurfaces that were digitalized on a TI thin film or non-directional surface plasmon polariton (SPP) excitation. Here, we numerically demonstrated the plasmonic capabilities of the TI Bi2Te3 as a material for gap–surface plasmon (GSP) metasurfaces. By employing the principle of the geometric phase, a far-field beam-steering metasurface was designed for the visible spectrum, yielding a cross-polarization efficiency of 34% at 500 nm while suppressing the co-polarization to 0.08%. Furthermore, a birefringent GSP metasurface design was studied and found to be capable of directionally exciting SPPs depending on the incident polarization. Our work forms the basis for accurately controlling the far- and near-field responses of TI-based GSP metasurfaces in the visible spectral range.

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Li, Panyi, Jiwei Zhao, Caofei Luo, Zhicheng Pei, Hui Jin, Yitian Huang, Wei Zhou et Bin Zheng. « Self-Adaptive Intelligent Metasurface Cloak System with Integrated Sensing Units ». Materials 17, n^o 19 (2 octobre 2024) : 4863. http://dx.doi.org/10.3390/ma17194863.

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Metasurfaces, which are ultrathin planar metamaterials arranged in certain global sequences, interact uniquely with the surrounding light field and exhibit unusual effects of light modulation. Many interesting applications have been discovered based on metasurfaces, particularly in invisibility cloaks. However, most invisibility cloaks are limited to working in specific directions. Achieving effectiveness in multiple directions requires the metasurface to be designed with both perception and modulation capabilities. Current multi-directional metasurface cloak systems are implemented with discrete components rather than an integrated sensing component. Here, we propose an intelligent metasurface cloak system that integrates sensing units, resulting in the cloaking effect with the help of a real-time direction sensor and an adaptive feedback control system. A reconfigurable reflective meta-atom based on phase modulation is presented. Sensing units replace parts of the meta-atoms in the designed tunable metasurface, integrating with an FPGA responsible for measuring the direction and frequency of the incident wave, constituting a closed-loop system together with the feedback parts. Experimental results demonstrate that the metasurface cloak system can recognize the different directions of the incoming wave, and can adaptively manipulate the reflected phase of EM waves to conceal objects without any human participation.

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Wu, Dong, Yang Meng et Chang Liu. « Design of Transparent Metasurfaces Based on Asymmetric Nanostructures for Directional and Selective Absorption ». Materials 13, n^o 17 (25 août 2020) : 3751. http://dx.doi.org/10.3390/ma13173751.

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Maximizing the solar heat gain through windows in winter and minimizing the solar radiation entering the room in summer are of great significance for the energy saving of buildings. Here, we present a new idea for transparent metasurfaces, based on asymmetric metal/insulator/metal (MIM) nanostructures, which can be switched back and forth between absorbing and reflecting solar radiation by reversing the sample orientation. Owing to the fundamental mode of a low-quality-factor resonance, a selective near-infrared absorption is obtained with an absorption peak value of 90% upon front illumination. The average solar absorption (45%) is about 10% higher than that (35%) of reported transparent absorbers. The near-infrared light is also strongly and selectively reflected upon back illumination and a reflection peak value above 70% is observed. Meanwhile, the average visible transmission of the metasurface is above 60%, which is about 1.6 times that (36%) of previous transparent metasurface absorbers. In addition, Cu material can replace the noble metals in this work, which will greatly reduce the manufacturing cost. Owing to the attractive properties of directional and selective absorption, passive operation mode, and low cost of the materials, the metasurfaces have promising prospects in building energy saving or other solar applications where surface transparency is desirable.

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Zhang, Song, Yilin Wang, Pengcheng Huo et Ting Xu. « Plasmonic spin-multiplexing metasurface for controlling the generation and in-plane propagation of surface plasmon polaritons ». Journal of Applied Physics 133, n^o 13 (7 avril 2023) : 133101. http://dx.doi.org/10.1063/5.0144421.

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Surface plasmon polaritons (SPPs) are electromagnetic waves that travel along a metal–dielectric interface and are finding an ever-increasing number of applications in newly emerging nano-photonic and optoelectronic technologies. Different from the traditional approach to excite SPPs using prism or grating, metallic metasurfaces incorporating nano-slots with different orientations enable the photonic spin-dependent directional coupling of SPPs, which shows the unique spin tunability. However, the propagations of these generated SPPs are still correlative due to the conjugated phase profiles of metasurfaces for two incident orthogonal spin states. Here, we propose a plasmonic spin-multiplexing metasurface composed of nano-slots with different geometric dimensions and orientations to efficiently control the near-field generation and in-plane propagation of SPPs. By taking into account both the geometric phase and resonant phase of the nano-slots, the metasurface can generate two independent and fully decoupled SPP fields for a pair of orthogonal spin states. As proof-of-concept, we design a series of spin-multiplexing metasurfaces to numerically demonstrate different near-field optical functionalities, including spin-controlled plasmonic bi-focusing, self-accelerating beams, and vortices. We envision this approach may have potential applications in designing polarization-dependent tunable plasmonic nano-devices.

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AKRAM, Md Tausif, et Kyungjun SONG. « Advanced directional beam control via holographic acoustic metasurfaces for multibeam scanning ». INTER-NOISE and NOISE-CON Congress and Conference Proceedings 270, n^o 11 (4 octobre 2024) : 736–42. http://dx.doi.org/10.3397/in_2024_2642.

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Acoustic multi-beam leaky-wave antennas, designed with holographic metasurfaces, have great potential for beamforming by achieving directional beam control. We propose a planar holographic metasurface for beam steering using multi-beam acoustic radiation serving as high-gain acoustic leaky wave antennas. Based on the principle of holography, we designed a metasurface that adjusts its admittance in a sinusoidal pattern. This surface consists of periodic cylindrical holes with varying depth profiles. A monopole point source is positioned in the middle of the patterned surface, which generates surface waves on the modulated surface and emits acoustic leaky-wave radiation in the desired directions. The holographic admittance surface is designed to radiate an acoustic beam at a frequency of 20 kHz. Additionally, the concept was extended to generate multi-beam scanning for forward leaky-wave radiation in the holographic process. In this research, we employed 3D additive manufacturing to create acoustic holograms, manipulating surface admittance variation at a resolution smaller than the wavelength. The experimental measurements aligned well with both the theoretical and numerical analysis findings, affirming the effectiveness of the proposed technique. The methodology exhibits broad applicability across various domains, including sonar, ultrasound imaging, waveform manipulation, and acoustic communication.

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Cheng, Yang, Yongfeng Li, He Wang, Jiafu Wang, Zhe Qin et Shaobo Qu. « Circular dichroism assisted bi-directional absorbers ». Journal of Physics D : Applied Physics 55, n^o 9 (17 novembre 2021) : 095101. http://dx.doi.org/10.1088/1361-6463/ac3301.

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Abstract Chirality, a geometric property that is of great importance in chemistry, biology, and medicine, has spurred many breakthroughs in the field of multi-dimensional metasurfaces that provide efficient ways of flexibly manipulating amplitude and phase of circular polarization (CP) waves. As one of the most important applications, chiral metamaterials can be used to implement novel absorbers. Herein, an ultra-thin wideband circular dichroic asymmetric metasurface was implemented via loading resistive film into chiral resonators. Opposite and reversible polarization conversion and circular dichroism (CD) were realized as being illuminated by CP waves from both sides meanwhile. Theoretical derivation and simulation verify that the polarization conversion and CD enhancement utilizing multi-layer CD metasurface. It is also found that the orientation angle of the meta-atom of each layer plays an important role in the CD enhancement, which paves a new way for CD enhancement. In addition, the coupling between the CD resonators was utilized to manipulate CD. On this basis, an ultra-thin polarization-insensitive absorber was achieved by employing a C4 2 × 2 CD resonator array, which was identical illuminating from front and back sides. Circular dichroic absorbers possess great potential in practical applications, ranging from stealth technology, antenna isolation, multi-functional microwave devices, chiral sensing, and catalysis.

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Santos, Gonzalo, Maria Losurdo, Fernando Moreno et Yael Gutiérrez. « Directional Scattering Switching from an All-Dielectric Phase Change Metasurface ». Nanomaterials 13, n^o 3 (26 janvier 2023) : 496. http://dx.doi.org/10.3390/nano13030496.

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All-dielectric metasurfaces are a blooming field with a wide range of new applications spanning from enhanced imaging to structural color, holography, planar sensors, and directionality scattering. These devices are nanopatterned structures of sub-wavelength dimensions whose optical behavior (absorption, reflection, and transmission) is determined by the dielectric composition, dimensions, and environment. However, the functionality of these metasurfaces is fixed at the fabrication step by the geometry and optical properties of the dielectric materials, limiting their potential as active reconfigurable devices. Herein, a reconfigurable all-dielectric metasurface based on two high refractive index (HRI) materials like silicon (Si) and the phase-change chalcogenide antimony triselenide (Sb2Se3) for the control of scattered light is proposed. It consists of a 2D array of Si–Sb2Se3–Si sandwich disks embedded in a SiO2 matrix. The tunability of the device is provided through the amorphous-to-crystalline transition of Sb2Se3. We demonstrate that in the Sb2Se3 amorphous state, all the light can be transmitted, as it is verified using the zero-backward condition, while in the crystalline phase most of the light is reflected due to a resonance whose origin is the contribution of the electric (ED) and magnetic (MD) dipoles and the anapole (AP) of the nanodisks. By this configuration, a contrast in transmission (ΔT) of 0.81 at a wavelength of 980 nm by governing the phase of Sb2Se3 can be achieved.

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Park, Yeonsang, Hyochul Kim, Jeong-Yub Lee, Woong Ko, Kideock Bae et Kyung-Sang Cho. « Direction control of colloidal quantum dot emission using dielectric metasurfaces ». Nanophotonics 9, n^o 5 (2 juin 2020) : 1023–30. http://dx.doi.org/10.1515/nanoph-2020-0158.

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AbstractOwing to the recent developments of dielectric metasurfaces, their applications have been expanding from those pertaining to the thickness shrinkage of passive optical elements, such as lenses, polarizers, and quarter-wave plates, to applications pertaining to their integration with active optical devices, such as vertical-cavity surface-emitting lasers. Even though directional lasing and beam shaping of laser emission have been successfully demonstrated, the integration of metasurfaces with random light sources, such as light-emitting diodes, is limited because of function and efficiency issues attributed to the fact that metasurfaces are basically based on the resonance property of the nanostructure. To control the direction of emission from colloidal quantum dots, we present a dielectric metasurface deflector composed of two asymmetric TiO2 nanoposts. TiO2 deflector arrays were fabricated with a dry etching method that is adaptive to mass production and integrated with a colloidal quantum dot resonant cavity formed by sandwiching two distributed Bragg reflectors. To ensure the deflection ability of the fabricated sample, we measured the photoluminescence and far-field patterns of emission from the resonant cavity. From the obtained results, we demonstrated that the colloidal quantum dot emission transmitted through our deflector arrays was deflected by 18°, and the efficiency of deflection was 71% with respect to the emission from the resonant cavity. This integration of dielectric metasurfaces with a resonant cavity shows the possibility of expanding the application of visible metasurfaces in active devices and may help to develop next-generation active devices with novel functions.

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Liu, Zhaoyong, Kailin Ren, Gaoyu Dai et Jianhua Zhang. « A Review on Micro-LED Display Integrating Metasurface Structures ». Micromachines 14, n^o 7 (30 juin 2023) : 1354. http://dx.doi.org/10.3390/mi14071354.

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Micro-LED display technology has been considered a promising candidate for near-eye display applications owing to its superior performance, such as having high brightness, high resolution, and high contrast. However, the realization of polarized and high-efficiency light extraction from Micro-LED arrays is still a significant problem to be addressed. Recently, by exploiting the capability of metasurfaces in wavefront modulation, researchers have achieved many excellent results by integrating metasurface structures with Micro-LEDs, including improving the light extraction efficiency, controlling the emission angle to achieve directional emission, and obtaining polarized Micro-LEDs. In this paper, recent progressions on Micro-LEDs integrated with metasurface structures are reviewed in the above three aspects, and the similar applications of metasurface structures in organic LEDs, quantum dot LEDs, and perovskite LEDs are also summarized.

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Thèses sur le sujet "Directional metasurfaces"

Wang, Dongxing. « Directional Optical Antennas, Wafer-Scale Metasurfaces, and Single Molecule Surface-Enhanced Raman Scattering ». Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11159.

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Within the field of optics, one of the topics being currently investigated with considerable interest is that of plasmonics, which refers to the use of surface plasmons on metallic nanostructures to manipulate light. It can be argued that this has been largely driven by two reasons. First, surface plasmons enable light to be concentrated into deep sub-wavelength regions, and therefore provide a means for overcoming the diffraction limit, which states that light can be focused to dimensions no smaller than roughly half the wavelength. Second, recent years have seen rapid development in nanofabrication methods - largely driven by applications in silicon microelectronics - that permit the realization of the metallic nanostructures needed for plasmonics. The goal of this thesis has been to harness these recent dramatic advances in plasmonics to address a long-standing problem in optics: the fact that Raman scattering cross sections are very small.
Engineering and Applied Sciences

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Nikitskiy, Nikita. « Propriétés d'émetteurs ultra-violets à base d'hétérostructures quantiques et de métasurfaces (Al,Ga)N ». Electronic Thesis or Diss., Université Côte d'Azur, 2024. http://www.theses.fr/2024COAZ5081.

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Les diodes électroluminescentes (LED) sont essentielles dans les technologies modernes, permettant une large gamme d'applications allant de l'éclairage à des usages spécialisés dans les domaines médicaux et environnementaux. Les LED ultra-violettes (UV), basées sur des hétérostructures à base d'alliages de nitrure d'aluminium et de gallium ((Al,Ga)N) avec des émetteurs quantiques, présentent un grand potentiel pour des applications telles que la stérilisation, la purification de l'eau et le diagnostic médical, grâce à leur efficacité énergétique, leur compacité et leur durée de vie plus longue par rapport aux lampes au mercure conventionnelles. Les systèmes à base d'(Al,Ga)N possèdent une bande interdite directe large et ajustable et est comprise entre 3.4 eV et 6.2 eV ce qui équivaut à une longueur d'onde d'émission de 365 nm et 200 nm respectivement. Cela fait rend particulièrement adaptés à l'émission de lumière sur un large spectre de longueurs d'onde dans la gamme UV, tandis que la capacité de dopage du matériau permet de réaliser des régions de type négatif (type n) et de type positif (type p), ce qui est nécessaire pour fabrication des LED. Malgré ces avantages, les LED UV basées sur l'(Al,Ga)N souffrent actuellement d'une efficacité quantique plus faible que à leurs homologues émettant dans le visible, en particulier en raison de la forte densité de défauts, des effets de polarisation de l'émission et de la faible extraction de la lumière. Cette thèse explore différentes voies permettant de remédier à ces problèmes. En particulier, l'utilisation de métasurfaces optiques, c'est-à-dire de réseaux de nanostructures, est envisagée pour améliorer l'émission des hétérostructures (Al,Ga)N. Le chapitre 1 présente l'état de l'art dans ce domaine ainsi que la motivation de ce travail. Le chapitre 2 offre une vue d'ensemble complète des propriétés fondamentales des matériaux (Al,Ga)N, notamment leurs caractéristiques cristallographiques et optiques. Il décrit également la croissance par épitaxie par jets moléculaires des boîtes quantiques (Al,Ga)N utilisées dans ce travail. Au chapitre 3, nous étudions expérimentalement l'influence de la relaxation mécanique des hétérostructures et de la qualité cristalline sur les propriétés optiques des boîtes quantiques émettant dans la gamme UV. Le chapitre 4 examine en profondeur la réponse photonique des matériaux (Al,Ga)N, offrant une analyse théorique et expérimentale des mécanismes d'interaction de la lumière et de la polarisation de l'émission. Enfin, le chapitre 5 traite de l'intégration des métasurfaces avec des émetteurs UV basés sur (Al,Ga)N pour améliorer le contrôle de l'émission et les performances globales du dispositif. L'utilisation de métasurfaces, capables de manipuler la lumière à l'échelle sub-longueur d'onde, est explorée comme une stratégie prometteuse pour augmenter l'extraction de la lumière en dirigeant et contrôlant l'émission dans la gamme UV
Light-emitting diodes (LEDs) are essential in modern technology, enabling a wide range of applications from general lighting to specialized uses in medical and environmental fields. Ultraviolet (UV) LEDs, based on heterostructures of aluminum gallium nitride alloys ((Al,Ga)N) with quantum emitters, hold significant promise for applications in sterilization, water purification, and medical diagnostics due to their energy efficiency, compact form, and longer lifespan compared to conventional mercury lamps.The(Al,Ga)N-based systems have a wide and tunable direct band gap ranging from 3.4 eV to 6.2 eV, which is equivalent to emission wavelengths of 365 nm and 200 nm, respectively. This makes them particularly suitable for light emission over a broad wavelength spectrum in the UV range, while the material doping capability supports both n-type and p-type doping regions, which is necessary for LED fabrication. Despite these advantages, UV LEDs based on (Al,Ga)N currently suffer from lower quantum efficiency compared to their visible-light counterparts, particularly due to high defect densities, emission polarization effects, and overall low light extraction.This work explores these challenges in more detail and also considers the possibility of improving the radiative characteristics of (Al,Ga)N heterostructures by embedding them into a metasurface. Chapter 1 introduces the state of the art in this topic and the motivation for this work. Chapter 2 presents a comprehensive overview of the fundamental properties of (Al,Ga)N materials, including their crystallographic and optical characteristics. It also describes the Molecular Beam Epitaxy growth of (Al,Ga)N quantum dots (QDs) used in this work. In Chapter 3, we experimentally investigate the influence of the mechanical relaxation of the heterostructures and the crystalline quality on the optical properties of the QDs emitting in the UV range. Chapter 4 delves into the photonic response of (Al,Ga)N materials, offering a theoretical and experimental analysis of light interaction mechanisms and emission polarization. Finally, Chapter 5 discusses the integration of metasurfaces with (Al,Ga)N-based UV emitters for improving emission control and overall device performance. The use of metasurfaces, which can manipulate light at the subwavelength scale, is explored as a promising strategy to increase light extraction efficiency by directing and controlling emission in the UV range

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Chapitres de livres sur le sujet "Directional metasurfaces"

Minin, I. V., G. V. Shuvalov et O. V. Minin. « All-dielectric asymmetrical metasurfaces based on mesoscale dielectric particles with different optical transmissions in opposite directions through full internal reflection ». Dans Frontier Research and Innovation in Optoelectronics Technology and Industry, 437–40. London, UK : CRC Press/Balkema, an imprint of the Taylor & Francis Group, [2019] : CRC Press, 2018. http://dx.doi.org/10.1201/9780429447082-64.

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Matsui, Tatsunosuke. « Electron Beam-Induced Directional Terahertz Radiation from Metamaterials ». Dans Metamaterials and Metasurfaces. IntechOpen, 2019. http://dx.doi.org/10.5772/intechopen.80648.

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Wang, Yinpeng. « A Comprehensive Review for Beam Steering Technology ». Dans Electromagnetic Wave Control Techniques of Metasurfaces and Metamaterials, 1–31. IGI Global, 2024. http://dx.doi.org/10.4018/979-8-3693-2599-5.ch001.

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Beam steering technology refers to technologies aiming at altering the propagation direction of the main lobe in radiation scenarios. Among the past decades, the beam steering technique has aroused people's attraction in various research directions. Simultaneously, multitudinous emerging realms like radar, biological imaging, wireless communication, and sensing are inseparable from beam steering. In this chapter, the authors have elaborated on the development of beam control technology from the classic mechanical prism to the latest spatiotemporal encoded metasurface. This review first covers geometric dependent methods, including mechanical control, MEMS control, liquid control, and optical control mechanisms, which are on the basis of Snell's law. After that, the phase control methods based on generalized Snell's law such as semiconductor components, electrically tunable materials, phase change materials, MEMS and spatiotemporal metasurfaces are discussed detailly. Finally, the authors summarize the methods of beam control and look forward to future possibilities.

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Sharma, Anuj Kumar, et Vipul Sharma. « Active and Passive Metamaterials and Metasurfaces ». Dans Advances in Wireless Technologies and Telecommunication, 297–319. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-8287-2.ch012.

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The authors of this chapter begin by discussing the fundamentals of metamaterials and metasurfaces before moving on to active and passive metamaterials. This chapter is broken up into six different sections. In the first section, an overview of metamaterials and metasurfaces is provided, and in the second half, active and passive metamaterials and metasurfaces are discussed. This is followed by an explanation of active metamaterials and metasurfaces in part three, fabrication methods for metamaterials and metasurfaces in part four, future directions and challenges in the field of metamaterials in part five, and a conclusion in part six.

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Ulomi, George Shilela, et Hassan Kilavo. « A Dual Band Frequency Reconfigurable Metasurface Antenna ». Dans Advances in Electronic Government, Digital Divide, and Regional Development, 246–54. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-6471-4.ch013.

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In this chapter, a single feed metasurface antenna with smooth dual-band frequency reconfiguration is proposed. The designed antenna has a simple and compact structure to be used in portable wireless communication devices. The antenna consists of two circular layers of substrate material placed one on top of the other. The lower layer is printed with a rectangular patch antenna in one side, and the other side is a ground plane. The upper substrate layer lay on top of patch antenna side is printed with a number of unit-cells on its upper side. To achieve frequency reconfiguration, the upper substrate layer is mechanically rotated at an angle θz in a clockwise direction along Z-axis. Based on rotation angle, the antenna scattering parameters (S11 and S21) of the unit cell are subjected to change which thereby affects relative permittivity of the upper layer resulting to a frequency reconfiguration.

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Iffat Naqvi, Syeda, et Niamat Hussain. « Antennas for 5G and 6G Communications ». Dans 5G and 6G Enhanced Broadband Communications [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.105497.

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An antenna is of substantial importance for a communication system as the design of an air interface is mainly reliant on the antenna design. With the significant wireless evolution from 1G to 6G, technologies and network capacities are also evolving to fulfill the promptly growing customer demands. These continually increasing demands have gone concurrently with extensive technological accomplishments of the antenna design community. This chapter discusses the sub-6 GHz and millimeter-wave (mm-wave) fifth-generation (5G) antennas, including antenna arrays, multiple-input, multiple-output (MIMO) technology, beam-steering techniques, metasurfaces, and other techniques to achieve the current and impending fast connectivity. Moreover, the design specifications, research directions, various technologies expected to be involved, and challenges in the design, fabrication, and measurement of the sixth-generation (6G) antennas at the THz band have also been presented. In addition, antenna-in-package (AiP) and antenna-on-chip (AoC) technologies with proper technology solutions have also been discussed.

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Actes de conférences sur le sujet "Directional metasurfaces"

Desai, Saaketh, Sadhvikas Addamane, Remi Dingreville, Igal Brener et Prasad P. Iyer. « Self-driving lab discovers high-efficiency directional incoherent emission from reconfigurable semiconductor metasurfaces ». Dans CLEO : Fundamental Science, FF1J.5. Washington, D.C. : Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cleo_fs.2024.ff1j.5.

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We discover high efficiency (77%) steering of incoherent emission from reconfigurable semiconductor metasurfaces by engineering the spatial refractive index profile of the metasurface resonators using autonomous experiments driven by generative models and active learning.

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Liu, Jianing, et Roberto Paiella. « Integrated plasmonic gradient metasurfaces for directional photodetection ». Dans CLEO : Fundamental Science, FM4O.2. Washington, D.C. : Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cleo_fs.2024.fm4o.2.

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We demonstrate the use of plasmonic gradient metasurfaces to tailor the angular response of generic planar photodetectors. The resulting devices are promising for a wide range of computational imaging applications with enhanced miniaturization and functionality.

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Audhkhasi, Romil, Maksym Zhelyeznyakov, Anna Wirth-Singh et Arka Majumdar. « Disordered Metasurface Doublets for Asymmetric Visibility and Synergistic Imaging in the Mid-infrared ». Dans CLEO : Fundamental Science, FTu4G.3. Washington, D.C. : Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cleo_fs.2024.ftu4g.3.

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We propose an all-silicon metasurface doublet that performs imaging in the mid-infrared only along a predefined light propagation direction. As a second application, we optimize two metasurfaces to perform imaging only when used in conjunction with each other.

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Chatzichristodoulou, David, Photos Vryonides, Dimitra Psychogiou et Symeon Nikolaou. « Directional Metasurface with Selective Polarization Using Antenna Elements ». Dans 2024 IEEE International Symposium on Antennas and Propagation and INC/USNC‐URSI Radio Science Meeting (AP-S/INC-USNC-URSI), 1561–62. IEEE, 2024. http://dx.doi.org/10.1109/ap-s/inc-usnc-ursi52054.2024.10686943.

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Munley, Christopher, Arnab Manna, Johannes Froech, Minho Choi et Arka Majumdar. « All-Dielectric Metasurface with a Locally Flat Photonic Band in All Directions ». Dans CLEO : Applications and Technology, JTu2A.168. Washington, D.C. : Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cleo_at.2024.jtu2a.168.

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Bashiri, Ayesheh, Aleksandr Vaskin, Katsuya Tanaka, Michael Steinert, Marijn Rikers, Maximilian A. Weissflog, Bayarjargal N. Tugchin, Thomas Pertsch et Isabelle Staude. « Normal-direction Yellow Laser Emission by Quasi-BIC TiO2 Metasurface ». Dans CLEO : Science and Innovations, SF3G.6. Washington, D.C. : Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cleo_si.2024.sf3g.6.

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We study the lasing action from rhodamine 6G laser dyes integrated with a quasi-BIC TiO2 metasurface supporting high Q-factor resonances. We experimentally observe low threshold lasing (8 nJ) at 568 nm from the integrated system.

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Wang, Chaohui, He-Xiu Xu, Tong Liu, Fan Zhang, Zhengjie Wang et Hui Wang. « Spin-Encoded Wavelength-Direction Multitasking Full-space metasurface ». Dans 2024 International Applied Computational Electromagnetics Society Symposium (ACES-China), 1–3. IEEE, 2024. http://dx.doi.org/10.1109/aces-china62474.2024.10699970.

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Pang, Cheng, Qiming Wang et Jiaran Qi. « Bi-Directional Compact Radiation-Type Metasurface Allowing for Full-Space Customized Beamforming ». Dans 2024 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 1–3. IEEE, 2024. http://dx.doi.org/10.1109/icmmt61774.2024.10672021.

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Salama, Norhan Ahmed, Salah S. A. Obayya et Mohamed A. Swillam. « Tailoring directional scattering in double Fano resonances based on coupled resonators metasurface ». Dans Photonic and Phononic Properties of Engineered Nanostructures XV, sous la direction de Ali Adibi, Shawn-Yu Lin et Axel Scherer, 59. SPIE, 2025. https://doi.org/10.1117/12.3043764.

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Zhuang, Yi, Jin Cheng Zhong, Yi Nan Zhao, Kun Wang et Zi Qian Yu. « ANN-enabled Direction Finding with Space-Time-Coding Metasurface ». Dans 2024 IEEE 12th Asia-Pacific Conference on Antennas and Propagation (APCAP), 1–2. IEEE, 2024. https://doi.org/10.1109/apcap62011.2024.10881721.

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