Article
Physics, Applied
Shaohua Dong, Shiqing Li, Xiaohui Ling, Guangwei Hu, Yi Li, Hongyi Zhu, Lei Zhou, Shulin Sun
Summary: This study introduces a high-efficiency and broadband spin-unlocked metasurface by combining the resonance phase and the geometric phase mechanisms. The design is achieved by changing one geometric parameter instead of multi-parameter optimization. Experimental results demonstrate the anomalous photonic spin Hall effect and completely independent wavefront manipulations achieved by the spin-unlocked metasurface.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Na-Li Zhang, Sheng-Dong Zhao, Hao-Wen Dong, Yue-Sheng Wang, Chuanzeng Zhang
Summary: In this paper, a reflection-type broadband acoustic coding metasurface (BACMs) is proposed, which utilizes the coupling resonance mechanism between square helical channels and air cavities to achieve encoding and decoding functions in a wide frequency range. The application of the BACMs is demonstrated through numerical simulation and experiments, showing potential for use in the field of acoustic wave devices.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Lin Xiao, Sheng He, Wenkang Cao, Jin Yang, Xuewei Liu, Liting Wu
Summary: This paper proposes amplitude-phase joint coding acoustic metasurfaces (APCMs) that enable simultaneous realization of acoustic wavefront engineering and energy allocation. By adjusting the geometrical parameters of the dual-layer meta-atoms, the reflection amplitude can be continuously controlled and the full reflection phase coverage can be achieved. Two examples are provided to verify the abilities of APCMs, and numerical simulation results confirm their effectiveness.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Guoqiang Li, Hongyu Shi, Jianjia Yi, Bolin Li, Anxue Zhang, Zhuo Xu
Summary: A transmission-reflection-integrated element and metasurface (MS) is proposed to manipulate the amplitudes, phases, and polarization states of electromagnetic waves in a full space. By introducing an amplitude-phase regulation structure to each element, the reflection and transmission can be controlled simultaneously under the same incident wave. The experimental results demonstrate that the proposed integrated element can generate deflective vortex beams with different values of topological charge in both the reflection and transmission modes.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Physics, Applied
Ping Han, Zhan-Dong Huang, Hao-Wen Dong, Sheng-Dong Zhao
Summary: We developed a reflective broadband acoustic coding metasurface utilizing bubble units. The reflected phase difference between the cube bubble unit and pure water unit is approximately pi across a wide range of frequencies. The broadband phenomenon is explained by the reflection theory between the soft water-air interface and the hard water-rigid interface. The relative bandwidth achieved is 187%, close to the theoretical limit of 200%. By reconstructing the 0/1 sequence, we conducted numerical simulations on broadband acoustic focusing and diffusing reflection. The research in this work has potential applications in enhancing underwater communication and cloaking.
APPLIED PHYSICS EXPRESS
(2023)
Article
Chemistry, Multidisciplinary
Yue Gou, Hui Feng Ma, Liang Wei Wu, Zheng Xing Wang, Peng Xu, Tie Jun Cui
Summary: In this study, a novel Pancharatnam-Berry (PB) coding metasurface composed of spin-decoupled elements is proposed to achieve broadband spin-selective reflections with arbitrary wavefront manipulations. The designed metasurface efficiently reflects the designated circularly polarized wave without reversing the spin state, while suppressing its orthogonally polarized wave through random diffusion. Both simulation and experiment results demonstrate the metasurface's chiral-like characteristics despite being composed of nonchiral meta-elements.
Article
Materials Science, Multidisciplinary
D. B. Moore, J. R. Sambles, A. P. Hibbins, T. A. Starkey, G. J. Chaplain
Summary: We design, simulate, and experimentally characterize an acoustic metasurface with a 1D array of open, sound-hard cavities modulated by beyond-nearest-neighbor (BNN) couplings. The hidden complex structure is realized with 3D printing. The structure supports negatively dispersing backwards waves, providing a route to enhanced acoustic sensing.
Article
Physics, Multidisciplinary
Yangyang Fu, Yuan Tian, Xiao Li, Shili Yang, Youwen Liu, Yadong Xu, Minghui Lu
Summary: In this study, a new method for achieving robust asymmetric generation of acoustic vortex field through dual-layer metasurfaces is introduced. This is achieved by controlling the intrinsic topologic charges and the parity of geometry design. The underlying physics is contributed to the one-way process of orbital angular momentum transition ensured by the broken spatial symmetry and the external topologic charge from the vortex diffraction. The novel phenomenon is experimentally demonstrated, providing new routes to manipulate the asymmetric response of vortex fields and potential applications in passive OAM-based diodes.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
O. Schnitzer, R. Brandao
Summary: This article discusses the absorption characteristics of finite metasurfaces and highlights the differences with infinite metasurfaces, particularly due to the excitation of surface waves.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2022)
Article
Chemistry, Multidisciplinary
Mingxin Xu, William S. Harley, Zhichao Ma, Peter V. S. Lee, David J. Collins
Summary: Acoustic metasurfaces with complex 3D structures complicate their fabrication and applicability to higher frequencies, but an ultrathin metasurface approach utilizing planarized micropillars in a discretized phase array is demonstrated here. This subwavelength metasurface can be easily produced via a single-step etching process and is suitable for megahertz-scale applications. The flexibility of this approach is further demonstrated in the production of complex acoustic patterns via acoustic holography. This metasurface approach, combined with predictive models, has broad potential for robust, high-frequency acoustic manipulation in various applications.
ADVANCED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Enrica Martini, Federico Giusti, Alice Benini, Stefano Maci
Summary: This paper investigates anisotropic self-complementary metasurfaces (SC-MTSs) consisting of complementary inductive and capacitive strips that are self-dual according to Babinet’s duality principle. These metasurfaces support the propagation of two orthogonally polarized surface-wave modes with the same phase velocity along the principal directions. The isofrequency dispersion curves of these modes are hyperbolas, and in some cases, they degenerate into almost straight lines. This property allows the SC-MTS to be used for designing dual-polarized leaky-wave antennas by modulating the impedances of the complementary strips.
Article
Materials Science, Multidisciplinary
Haixiao Zhang, Yiwei Zhang, Xiaoli Liu, Yu Bao, Jinyu Zhao
Summary: This paper introduces a new method to realize the extraordinary physical property of impurity-shielding, achieving perfect transmission at exceptional points. By investigating the system composed of PT-symmetric metasurfaces sandwiching a medium slab, the two complementary solutions of exceptional points corresponding to perfect transmission are obtained. The impurity-shielding effect can be perfectly demonstrated when the mass density of the slab approaches zero, and the proposed system is frequency independent.
Article
Nanoscience & Nanotechnology
Liang Xu, Dan Yang Wang, Xin Ge Zhang, Lin Bai, Wei Xiang Jiang, Tie Jun Cui
Summary: Information technology is advancing towards interconnected and intelligent connections of all objects. A networked metasurface with online electromagnetic manipulation capabilities has been proposed and realized, allowing multiple users to access and control the reflected beams through cloud connections. Experimental results demonstrate the online programmability of the networked metasurface. This approach provides a practical route for realizing networked metasurfaces, with potential applications in smart electromagnetic control nodes, distributed cooperative metasurface systems, and metasurface-assisted wireless networks.
Article
Chemistry, Multidisciplinary
Lei Chen, Qian Ma, Si Si Luo, Fu Ju Ye, Hao Yang Cui, Tie Jun Cui
Summary: This paper introduces a touch-programmable metasurface (TPM) based on touch sensing modules, which can achieve various electromagnetic (EM) manipulations and encryptions by touch controls. The TPM simplifies the coding regulation process and provides a new interaction manner, enabling independent and direct manipulations of meta-units and efficient inputs of coding patterns. The feasibility of the TPM design is verified through various coding patterns, demonstrating its wide application prospects.
Article
Optics
Zuyu Li, Yuhang Zhang, Hui Huang, Shuai Qin, Kaiqian Jie, Hongzhan Liu, Jianping Guo, Hongyun Meng, Faqiang Wang, Xiangbo Yang, Zhongchao Wei
Summary: This study proposes a single layer multifunctional metasurface for independently and simultaneously displaying nanoprinting and holographic images. By tailoring the dimensions and orientation angle of nanobricks, the amplitude and phase can be artificially designed. Compared with previous work, our metasurfaces significantly improve the quality of holographic images while not affecting nanoprinting images, with simple structures.
Article
Optics
Mohammad Sajjad Mirmoosa, Xuchen Wang, Lukas Freter, Ari Sihvola, Sergei Tretyakov
Summary: Generalized duality transformations modify constitutive relations of electromagnetic media while preserving principal electromagnetic properties. In this work, we consider the transformation of Tellegen nihility as a specific type of extreme-property nonreciprocal bi-isotropic media and demonstrate that intriguing electromagnetic properties of that medium can be realized in a certain class of isotropic magnetodielectric media without magnetoelectric coupling. We show that the transformed medium exhibits permittivity and permeability values with equal absolute values and opposite signs.
Article
Nanoscience & Nanotechnology
Xuchen Wang, Mohammad S. S. Mirmoosa, Sergei A. A. Tretyakov
Summary: This paper theoretically elucidates the effect of temporal discontinuities of effective parameters on the propagation of reactive metasurface surface waves. It shows that by switching the surface reactance value, the velocity of surface waves can be fully controlled, and the power of reflected and transmitted waves can be amplified. It also demonstrates that switching a boundary from supporting transverse-electric polarization to only allowing transverse-magnetic polarization freezes and converts the propagating surface wave to a static magnetic-field distribution. Furthermore, temporal jumps of the boundary reactance couple free-space propagating waves to the surface wave, similar to a spatial prism. These intriguing phenomena enable the generation and control of surface waves.
Article
Physics, Applied
J. A. Alvarez-Sanchis, B. Vidal, S. A. Tretyakov, A. Diaz-Rubio
Summary: By controlling geometric parameters, the quality factor of all-dielectric metasurfaces can be adjusted and designed theoretically for improved performance as sensors in the THz band. However, material losses significantly limit the resonances' quality factor, leading to the proposal of all-dielectric metasurfaces as an alternative to metal-dielectric structures. In this study, the effect of losses on all-dielectric metasurfaces is examined using realistic materials, and their sensing performance is compared with nanostructures supporting extraordinary optical transmission. The results highlight the limitations of all-dielectric metasurfaces and the superiority of structures with extraordinary optical transmission.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Applied
Hamidreza Taghvaee, Fu Liu, Ana Diaz-Rubio, Sergei Tretyakov
Summary: Breaking the diffraction limit on optical devices and achieving subwavelength focusing requires tailoring the evanescent spectrum of wave fields. This paper presents a feasible strategy based on the concepts of the perfect lens and power flow-conformal metasurfaces, allowing for subwavelength hotspot size in near-field focusing. The findings have potential applications in antennas, beam-shaping devices, nonradiative wireless power transfer systems, microscopy, and lithography.
PHYSICAL REVIEW APPLIED
(2023)
Article
Multidisciplinary Sciences
Xuchen Wang, Mohammad Sajjad Mirmoosa, Viktar S. Asadchy, Carsten Rockstuhl, Shanhui Fan, Sergei A. Tretyakov
Summary: Photonic time crystals are artificial materials with spatially uniform but temporally varying electromagnetic properties. This study extends the concept of photonic time crystals to two-dimensional artificial structures called metasurfaces. By designing a microwave metasurface, the researchers confirmed the existence of momentum bandgaps and exponential wave amplification, demonstrating the potential of metasurfaces as a material platform for emerging photonic space-time crystals and for amplifying surface-wave signals in wireless communications.
Article
Chemistry, Multidisciplinary
Shuomin Zhong, Xuchen Wang, Sergei A. A. Tretyakov
Summary: Conventional coherent absorption occurs only when two incident beams exhibit mirror symmetry. This study proposes a more general metasurface paradigm for coherent perfect absorption with impinging waves from arbitrary asymmetric directions. It shows theoretically and confirms experimentally that the relative amplitude of the reflected wave can be continuously tuned by changing the phase difference between the two beams, opening up promising possibilities for wave manipulation with applications in various fields.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Physics, Applied
N. Ha-Van, C. R. Simovski, F. S. Cuesta, P. Jayathurathnage, S. A. Tretyakov
Summary: In conventional inductive wireless power devices, energy is transferred via reactive near fields, and radiation from transmitting and receiving coils is considered a parasitic effect that reduces power-transfer efficiency. This paper develops a dynamic theory of wireless power transfer between two small loop antennas, clarifies the role of far-field radiation, and proposes a possibility to achieve efficient wireless power transfer at large distances through radiation suppression. The analytical results are validated through simulations and measurements, offering the potential to greatly expand the distance range of compact wireless power-transfer devices.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Applied
G. A. Ptitcyn, M. S. Mirmoosa, S. Hrabar, S. A. Tretyakov
Summary: Temporal modulation allows dynamic control and modification of electromagnetic system response, enabling functionalities that were conventionally unachievable. By explicitly considering the time dependence of circuit or surface parameters, it becomes possible to emulate electromagnetic systems with arbitrary frequency dispersion and nonlinear properties, including non-Foster response. Proper modulation of a time-varying capacitor can mimic static inductance, capacitance, or resistance with arbitrary values, positive or negative. The stability of the system is ensured through necessary modifications of determined ideal modulation functions. A proposed invisible sensor is demonstrated using full-wave simulations, along with discussions on the stability of externally modulated systems. This study introduces an alternative paradigm of using time modulations to engineer system responses, applicable not only to electromagnetic systems but also in other branches of physics.
PHYSICAL REVIEW APPLIED
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Sergei Kosulnikov, Francisco S. Cuesta, Xuchen Wang, Ana Diaz-Rubio, Sergei Tretyakov
Summary: High-frequency wireless communications at millimeter-wave bands require directive, high-gain antennas to achieve longer communication links. Anomalously reflecting and reconfigurable intelligent surfaces can be used to ensure sufficient space coverage. This presentation discusses recent analytical estimations of link budget with the presence of such reflectors, providing simple expressions for the far field using macroscopic reflection coefficients and a generalized Friis formula. The analytical results are validated through numerical simulations of a specific realization for millimeter-wave frequency band.
2023 17TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION, EUCAP
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Yongming Li, Xikui Ma, Grigorii Ptitcyn, Sergei Tretyakov
Summary: In this study, a novel method is proposed for designing anomalous reflectors using arrays of loaded strips. By assuming two different sets of induced polarization currents flowing on the surface, specular reflection can be eliminated and the reflected wave propagates towards the desired direction. Surface waves are tuned by optimizing the current distribution to obtain purely reactive loads. Additional loaded strips inserted within a lambda/2-sized cell of the structure help optimize the design, and perfect anomalous reflection is achieved. The obtained results are compared with conventional reflectarrays, demonstrating significant improvement.
2023 17TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION, EUCAP
(2023)
Article
Materials Science, Multidisciplinary
F. S. Cuesta, M. S. Mirmoosa, S. A. Tretyakov
Summary: One advantage of reciprocal bianisotropic metasurfaces is their ability to produce asymmetric scattering depending on the illumination side and circular polarization. However, we demonstrate that geometrical asymmetry can be emulated using nonbianisotropic layers in coherent illumination, enabling optical control of desired asymmetric scattering and chirality effects. We illustrate this concept by emulating asymmetric scattering required for creating a 180 degrees hybrid junction for plane waves using either a bianisotropic metasurface or simple sheets with electric response under simultaneous illumination by two coherent waves.
Proceedings Paper
Engineering, Electrical & Electronic
Nam Ha-Van, Constantin R. Simovski, Francisco S. Cuesta, Prasad Jayathurathnage, Sergei A. Tretyakov
Summary: We investigate a regime of radiation suppression in wireless power transfer (WPT) between two loop antennas in free space. By optimizing load impedance and working frequency, high power transfer efficiency can be achieved due to partial compensation of the radiation resistances of both antennas. This regime is analyzed for two antenna arrangements: coaxial arrangement, where WPT is solely based on near fields, and coplanar arrangement, where both near-field and far-field power transfer mechanisms are combined. The radiation suppression regime is analyzed and visualized for both arrangements. Theoretical results are validated by simulations and experiments with two loop antennas.
2023 53RD EUROPEAN MICROWAVE CONFERENCE, EUMC
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Shamsul Arefeen Al Mahmud, Prasad Jayathurathnage, Yining Liu, Jorma Kyyra
Summary: Fast automatic identification of WPT receiver is critical for future deployment of efficient and low-cost dynamic wireless power transfer devices. This article presents a new approach for receiver identification and transmitter activation in wireless power transfer systems, enabling fast charging request and energy-saving.
2023 IEEE WIRELESS POWER TECHNOLOGY CONFERENCE AND EXPO, WPTCE
(2023)