- 标题
- 摘要
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- 实验方案
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Ruler equation for precisely tailoring the resonance frequency of terahertz U-shaped metamaterials
摘要： Artificially controlling the spectral response of metamaterials is important for the applications of functional devices. Here, we identify a simple ruler equation for describing the direct relation between the resonance frequencies and geometric parameters in terahertz U-shaped metamaterials. Utilizing this ruler equation, we demonstrate the switching of the multi-band resonator which can be customized to work at expectant frequency bands. This ruler equation provides a practical guidance on tailoring the resonance frequency and paves the way for the development of metamaterial-based terahertz functional devices.
关键词： terahertz,surface plasmon,metamaterials
更新于2025-09-23 15:23:52
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Study of In-Plane Wave Propagation in 2-Dimensional Anisotropic Elastic Metamaterials
摘要： Objective Due to its multiple applications, elastic metamaterial is of great interest for researchers today. In this article, in-plane wave propagation in 2-D anisotropic metamateials with anisotropic density and anisotropic Young’s modulus is comprehensively studied. Method Characteristics of wave propagation in 2-D metamaterial with different combinations of negative properties are provided, and the unnatural phenomenon is also explained. Based on Snell’s law and weld boundary condition, analysis of wave propagation from conventional isotropic material into anisotropic metamaterial is performed. Significance This paper can serve as a foundation for future study of massive modeling and simulation of both isotropic and anisotropic metamaterials.
关键词： Anisotropy,Snell’s law,Wave propagation,Christoffel equations,Elastic metamaterials
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Design of a Metamaterial Element in Deep Subwavelength Composed of Multilayer Meander Line (MML) Resonator Structures
摘要： An extremely compact metamaterial element is proposed with multilayer meander line (MML) resonator inclusions. The MML is featured with multiple single-planar meander line (SML) structures which are connected by via. The effective inductance in the new MML structure is thus multiplied leading to a reduced resonance frequency. A proof MML element is numerically demonstrated with period of 8mm. Very strong electric responses have been observed indicating the MML element is essentially a kind of electrically resonating structure. The proof MML element resonances at 237MHz in VHF band. The electrical period size is 1/158λ0 which is in deep subwavelength. By making the meander line thinner or incorporating more SML layers, the effective inductance can be further enhanced and the structure is more compact which is promising for radio frequency metamaterial designs in future.
关键词： compact element,multilayer meander line (MML) structure,Metamaterials
更新于2025-09-23 15:22:29
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[IEEE NAECON 2018 - IEEE National Aerospace and Electronics Conference - Dayton, OH, USA (2018.7.23-2018.7.26)] NAECON 2018 - IEEE National Aerospace and Electronics Conference - Electromagnetic Propagation across an Achiral/Chiral (Dispersive) Boundary Using Phasor Approach to Fresnel Coefficients
摘要： Electromagnetic propagation across an achiral/chiral interface has been studied to evaluate Fresnel coefficients and examine the propagation characteristics. Extending the problem to include dispersive chiral dielectrics and discrete components may lead to potential applications such as tunable superlenses (with imaging and vision implications) and also devices including chiral Fabry-Perot etalons.
关键词： Fresnel coefficients,chiral Fabry-Perot resonator,metamaterials,chiral media,internal reflection,anomalous Brewster phenomenon
更新于2025-09-23 15:22:29
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Microstrip Line Impedance Matching Using ENZ Metamaterials, Design and Application
摘要： The idea of this paper is to extend the tunneling effect of epsilon-near-zero (ENZ) narrow channel for matching two microstrip lines with different impedance characteristics. The main advantage of this method is the possibility to design a channel with subwavelength electrical size and obtain similar matching condition when compared with a conventional λ/4-transformer. The bandwidth of the structure is directly related to the bandwidth of the ENZ-metamaterials (MTM). The suggested matching circuit is comprised of a metallic wall and an ENZ narrow channel. To realize the ENZ channel, a rectangular waveguide which operates in TE10 mode is designed and implemented using a substrate integrated waveguide (SIW) technology. A set of vias are also needed for emulating the metallic wall to reduce the ENZ channel cross section. The proposed structure for different impedance values of 50?, 100?, and 150? was designed, simulated, fabricated, and tested. Moreover, as an important application of a matching network, a microstrip patch antenna has been matched over the desired frequency band. Simulation results based on CST microwave studio have good agreement with measurements. It is shown that the bandwidth of the circuit is 8%–15%.
关键词： impedance matching,metamaterials (MTM),Epsilon-near-zero (ENZ),microstrip line,tunneling
更新于2025-09-23 15:22:29
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On loss compensation, amplification and lasing in metallic metamaterials
摘要： The design of metamaterials, which are artificial materials that can offer unique electromagnetic properties, is based on the excitation of strong resonant modes. Unfortunately, material absorption—mainly due to their metallic parts—can damp their resonances and hinder their operation. Incorporating a gain material can balance these losses, but this must be performed properly, as a reduced or even eliminated absorption does not guarantee loss compensation. Here we examine the possible regimes of interaction of a gain material with a passive metamaterial and show that background amplification and loss compensation are two extreme opposites, both of which can lead to lasing.
关键词： loss compensation,split-ring resonator,active media,lasing,nanophotonics,Metamaterials
更新于2025-09-23 15:22:29
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[OSA CLEO: Science and Innovations - San Jose, California (2014..-..)] CLEO: 2014 - Terahertz near-field phase contrast imaging
摘要： We demonstrate a method, permitting the observation of dielectric loading of hydrocarbons into a porous coordination polymer nanocrystal (PCP), by spatially resolving the phase difference between the near-field responses of two terahertz resonators.
关键词： Near-field microscopy,terahertz,Spectroscopy,Metamaterials
更新于2025-09-23 15:22:29
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Ultrathin Microwave Devices for Polarization-Dependent Wavefront Shaping Based on an Anisotropic Metasurface
摘要： Metasurfaces have recently become a promising material, offering new degrees of freedom in molding electromagnetic wave properties. In this work, we propose and numerically investigate ultrathin microwave devices for polarization-dependent wavefront shaping based on an anisotropic metasurface, which consists of a square metal ring with a cross, a dielectric substrate, and a metal ground plane. It is demonstrated the proposed metasurface can independently manipulate reflective x- and y-polarized wavefronts at frequency of 15 GHz via engineering of the metal cross. Furthermore, the reflective efficient is extremely high, reaching a near-unity value of 0.98. Based on this anisotropic metasurface, a polarization beam splitter is achieved by artificially arranging the spatial distribution of metasurfaces with prescribed geometries. In addition, we successfully design a focusing metasurface to separate the x- and y-polarized beams via focusing them at different positions. The proposed approach paves a way toward the applications of the metasurface in a microwave band.
关键词： electromagnetic metamaterials,microwave propagation,beam steering,microwave antennas
更新于2025-09-23 15:22:29
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Analytical model of the fundamental mode of 3D square split ring resonators
摘要： An analytical model is developed for the charge and potential distributions of the fundamental mode of three-dimensional (3D) singly split ring resonators (SRRs) with square cross section, which nowadays can be conveniently fabricated by additive manufacturing techniques. This model allows the derivation of approximate formulas for the equivalent capacitance and the analysis of the resonant properties of this type of SRRs at any frequency. The total capacitance is expressed as the sum of the usual gap capacitance and a surface capacitance associated with the charges on the SRR walls, which are determined from the solution for the irrotational part of the electric field of a square split cylinder obtained by conformal mapping. The applicability of the proposed model for a broad range of SRR parameters is demonstrated by comparing the resonance frequency of sample SRR configurations found theoretically with the corresponding values obtained by numerical simulations and experiments. Furthermore, the functions describing the charge and current mode profiles provided in this work can be instrumental in estimating the near-field interaction and the coupling constants of an ensemble of resonant 3D square split rings and thus for tailoring the response of metamaterials and other devices formed by these elements.
关键词： capacitance,resonance frequency,analytical model,split ring resonators,metamaterials
更新于2025-09-23 15:22:29
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All-Optical Transmission Modulation Due to Inelastic Interactions of Ultrashort Pulses in a Disordered Resonant Medium
摘要： Random resonant media being one of the possible realizations of disordered metamaterials open a room of opportunities for achieving new fundamental effects and designing advanced nanophotonic devices. Strongly nonlinear optical properties of such media attract ever increasing attention nowadays from both theoretical and experimental points of view. Hereinafter, the case of the photonic-crystal-like structure with a randomly varying light–matter coupling provided by the random density of quantum particles is considered. Using numerical solution of the Maxwell–Bloch equations, the effects of the pulse collisions in the medium are studied. It is shown that disorder enables the qualitative changes of the system’s response for co-propagating pulses, whereas this is not the case for the counter-propagating ones. The scheme for an all-optical transmission modulation due to the disorder-induced inelasticity of collisions of co-propagating pulses is proposed. The ability of precise tuning the modulation via the inter-pulse distance and background refractive index adjustment is revealed. This novel approach for light control can be utilized for some high demand applications, such as modulation and switching of a pulsed radiation.
关键词： disordered metamaterials,transmission modulation,ultrashort pulses,localization of light,resonant medium
更新于2025-09-23 15:22:29