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Guang-Ming Wang

Bio: Guang-Ming Wang is an academic researcher from University of Science and Technology, Liaoning. The author has contributed to research in topics: Antenna (radio) & Metamaterial. The author has an hindex of 34, co-authored 117 publications receiving 3393 citations.

Papers published on a yearly basis

Papers
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Journal ArticleDOI
TL;DR: In this article, a general strategy to design high-efficiency bifunctional devices based on metasurfaces composed by anisotropic meta-atoms with polarization-dependent phase responses is described.
Abstract: Achieving multiple diversified functionalities in a single flat device is crucial for electromagnetic (EM) integration, but available efforts suffer the issues of device thickness, low efficiency, and restricted functionalities. Here, a general strategy to design high-efficiency bifunctional devices based on metasurfaces composed by anisotropic meta-atoms with polarization-dependent phase responses is described. Based on the derived general criterions, two bifunctional metadevices, working in reflection and transmission modes, respectively, that can realize two distinct functionalities with very high efficiencies (≈90% in reflection geometry and ≈72% in transmission one) are designed and fabricated. Microwave experiments, including both far-field and near-field characterizations, are performed to demonstrate the predicted effects, which are in excellent agreement with numerical simulations. The findings in this study can motivate the realizations of high-performance bifunctional metadevices in other frequency domains and with different functionalities, which are of crucial importance in EM integration.

204 citations

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TL;DR: In this article, a high-gain transmitting lens antenna by employing layered phase-gradient metasurface (MS) was proposed to focus the propagating plane wave to a point with high efficiency.
Abstract: We propose a high-gain transmitting lens antenna by employing layered phase-gradient metasurface (MS). The MS is engineered to focus the propagating plane wave to a point with high efficiency. An X-band patch antenna is placed at the focal point of the MS as a feed source, and then the quasi-spherical wave emitted by the source is transformed to plane wave. Due to the successful conversion of quasi-spherical wave to plane wave, the beam width of the patch antenna has been decreased 66° and the gain has been enhanced 11.6 dB. The proposed lens antenna not only opens up a new route for the applications of phase-gradient MS in microwave band, but also affords an alternative for high-gain antenna.

189 citations

Journal ArticleDOI
TL;DR: In this article, three ultrathin devices with multiple polarization-dependent functionalities and very high efficiencies on both transmission and reflection sides were designed to manipulate EM waves in either mode, which significantly expand the capabilities of metasurfaces for more demanding and diverse applications.
Abstract: Metasurfaces offer great opportunities to control light, but so far most ``metadevices'' work either in pure reflection or pure transmission mode, leaving half of electromagnetic (EM) space untapped. Thus the authors design meta-atoms with polarization-dependent transmission and reflection properties, to efficiently manipulate EM waves in either mode. They fabricate three ultrathin devices with multiple polarization-dependent functionalities and very high efficiencies on both transmission and reflection sides. These findings significantly expand the capabilities of metasurfaces for more demanding and diverse applications.

169 citations

Journal ArticleDOI
TL;DR: In this paper, the authors report on the design, fabrication, and measurement of a triple-band absorber enhanced from a planar two-dimensional artificial metamaterial transmission line (TL) concept.
Abstract: We report on the design, fabrication, and measurement of a triple-band absorber enhanced from a planar two-dimensional artificial metamaterial transmission line (TL) concept. Unlike previous multiband absorbers, this implementation incorporates fractal geometry into the artificial TL framework. As a consequence of the formed large $LC$ values, the utilized element is compact in size, which approaches ${\ensuremath{\lambda}}_{0}$/15 at the lowest fundamental resonant frequency. For independent control and design, a theoretical characterization based on a circuit model analysis (TL theory) is performed and a set of design procedures is also derived. Both numerical and experimental results have validated three strong absorption peaks across the $S$, $C$, and $X$ bands, respectively, which are attributable to a series of self-resonances induced in the specific localized area. The absorber features near-unity absorption for a wide range of incident angles and polarization states and a great degree of design flexibility by manipulating the $LC$ values in a straightforward way.

147 citations

Journal ArticleDOI
TL;DR: An interference-assisted metasurface-multiplexer (meta-plexer) that counterintuitively exploits constructive and destructive interferences between hybrid meta-atoms and realizes independent spin-selective wavefront manipulation is proposed.
Abstract: Achieving simultaneous polarization and wavefront control, especially circular polarization with the auxiliary degree of freedom of light and spin angular momentum, is of fundamental importance in many optical applications. Interferences are typically undesirable in highly integrated photonic circuits and metasurfaces. Here, we propose an interference-assisted metasurface-multiplexer (meta-plexer) that counterintuitively exploits constructive and destructive interferences between hybrid meta-atoms and realizes independent spin-selective wavefront manipulation. Such kaleidoscopic meta-plexers are experimentally demonstrated via two types of single-layer spin-wavefront multiplexers that are composed of spatially rotated anisotropic meta-atoms. One type generates a spin-selective Bessel-beam wavefront for spin-down light and a low scattering cross-section for stealth for spin-up light. The other type demonstrates versatile control of the vortex wavefront, which is also characterized by the orbital angular momentum of light, with frequency-switchable numbers of beams under linearly polarized wave excitation. Our findings offer a distinct interference-assisted concept for realizing advanced multifunctional photonics with arbitrary and independent spin-wavefront features. A variety of applications can be readily anticipated in optical diodes, isolators, and spin-Hall meta-devices without cascading bulky optical elements.

139 citations


Cited by
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Journal ArticleDOI
TL;DR: In this article, the basic physics and applications of planar metamaterials, often called metasurfaces, which are composed of optically thin and densely packed planar arrays of resonant or nearly resonant subwavelength elements, are reviewed.

1,047 citations

Journal ArticleDOI
TL;DR: In this paper, a double V-shaped metasurface that can efficiently convert linear polarizations of electromagnetic (EM) waves in wideband is proposed, which can be used in many applications, such as reflector antennas, imaging systems, remote sensors, and radiometers.
Abstract: In this paper, a double V-shaped metasurface that can efficiently convert linear polarizations of electromagnetic (EM) waves in wideband is proposed. Based on the electric and magnetic resonant features of a single V-shaped particle, four EM resonances are generated in a V-shaped pair, leading to significant bandwidth expansion of cross-polarized reflections. The simulation results show that the proposed metasurface is able to convert linearly polarized waves into cross-polarized waves in ultrawideband from 12.4 to 27.96 GHz, with an average polarization conversion ratio (PCR) of 90%. The experimental results are in good agreement with the numerical simulations. Compared to published designs, the proposed polarization converter has a simple geometry but an ultrawideband and hence can be used in many applications, such as reflector antennas, imaging systems, remote sensors, and radiometers. The method can also be extended to the terahertz band.

493 citations

Journal ArticleDOI
TL;DR: The fundamental building blocks essential for the realization of metasurfaces are discussed in order to elucidate the underlying physics of various physical realizations of both plasmonic and purely dielectric metAsurfaces.
Abstract: In the wake of intense research on metamaterials the two-dimensional analogue, known as metasurfaces, has attracted progressively increasing attention in recent years due to the ease of fabrication and smaller insertion losses, while enabling an unprecedented control over spatial distributions of transmitted and reflected optical fields. Metasurfaces represent optically thin planar arrays of resonant subwavelength elements that can be arranged in a strictly or quasi periodic fashion, or even in an aperiodic manner, depending on targeted optical wavefronts to be molded with their help. This paper reviews a broad subclass of metasurfaces, viz. gradient metasurfaces, which are devised to exhibit spatially varying optical responses resulting in spatially varying amplitudes, phases and polarizations of scattered fields. Starting with introducing the concept of gradient metasurfaces, we present classification of different metasurfaces from the viewpoint of their responses, differentiating electrical-dipole, geometric, reflective and Huygens' metasurfaces. The fundamental building blocks essential for the realization of metasurfaces are then discussed in order to elucidate the underlying physics of various physical realizations of both plasmonic and purely dielectric metasurfaces. We then overview the main applications of gradient metasurfaces, including waveplates, flat lenses, spiral phase plates, broadband absorbers, color printing, holograms, polarimeters and surface wave couplers. The review is terminated with a short section on recently developed nonlinear metasurfaces, followed by the outlook presenting our view on possible future developments and perspectives for future applications.

417 citations

Journal Article
TL;DR: In this paper, it was shown that ZnO samples can be magnetic even without transition-metal doping and also suggests that introducing Zn vacancy is a natural and an effective way to fabricate magnetic ZNO nanostructures.
Abstract: Extensive calculations based on density functional theory have been carried out to understand the origin of magnetism in undoped ZnO thin films as found in recent experiments. The observed magnetism is confirmed to be due to Zn, instead of O, vacancy. The main source of the magnetic moment, however, arises from the unpaired 2p electrons at O sites surrounding the Zn vacancy with each nearest-neighbor O atom carrying a magnetic moment ranging from 0.490 to 0.740 B. Moreover, the study of vacancy-vacancy interactions indicates that in the ground state, the magnetic moments induced by Zn vacancies prefer to ferromagnetically couple with the antiferromagnetic state lying 44 meV higher in energy. Since this is larger than the thermal energy at room temperature, the ferromagnetic state can be stable against thermal fluctuations. Calculations and discussions are also extended to ZnO nanowires that have larger surface to volume ratio. Here, the Zn vacancies are found to lead to the ferromagnetic state too. The present theoretical study not only demonstrates that ZnO samples can be magnetic even without transition-metal doping but also suggests that introducing Zn vacancy is a natural and an effective way to fabricate magnetic ZnO nanostructures. In addition, vacancy mediated magnetic ZnO nanostructures may have certain advantages over transition-metal doped systems in biomedical applications.

357 citations