Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Independent control of differently-polarized waves using anisotropic gradient-index metamaterials.

ABSTRACT: We propose a kind of anisotropic gradient-index (GRIN) metamaterials, which can be used to control differently-polarized waves independently. We show that two three- dimensional (3D) planar lenses made of such anisotropic GRIN metamaterials are able to make arbitrary beam deflections for the vertical (or horizontal) polarization but have no response to the horizontal (or vertical) polarization. Then the vertically- and horizontally-polarized waves are separated and controlled independently to deflect to arbitrarily different directions by designing the anisotropic GRIN planar lenses. We make experimental verifications of the lenses using such a special metamaterial, which has both electric and magnetic responses simultaneously to reach approximately equal permittivity and permeability. Hence excellent impedance matching is obtained between the GRIN planar lenses and the air. The measurement results demonstrate good performance on the independent controls of differently-polarized waves, as observed in the numerical simulations.

SUBMITTER: Ma HF

PROVIDER: S-EPMC4166714 | biostudies-other | 2014

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Similar Datasets

Anisotropic coding metamaterials and their powerful manipulation of differently polarized terahertz waves.

Project description:Metamaterials based on effective media can be used to produce a number of unusual physical properties (for example, negative refraction and invisibility cloaking) because they can be tailored with effective medium parameters that do not occur in nature. Recently, the use of coding metamaterials has been suggested for the control of electromagnetic waves through the design of coding sequences using digital elements '0' and '1,' which possess opposite phase responses. Here we propose the concept of an anisotropic coding metamaterial in which the coding behaviors in different directions are dependent on the polarization status of the electromagnetic waves. We experimentally demonstrate an ultrathin and flexible polarization-controlled anisotropic coding metasurface that functions in the terahertz regime using specially designed coding elements. By encoding the elements with elaborately designed coding sequences (both 1-bit and 2-bit sequences), the x- and y-polarized waves can be anomalously reflected or independently diffused in three dimensions. The simulated far-field scattering patterns and near-field distributions are presented to illustrate the dual-functional performance of the encoded metasurface, and the results are consistent with the measured results. We further demonstrate the ability of the anisotropic coding metasurfaces to generate a beam splitter and realize simultaneous anomalous reflections and polarization conversions, thus providing powerful control of differently polarized electromagnetic waves. The proposed method enables versatile beam behaviors under orthogonal polarizations using a single metasurface and has the potential for use in the development of interesting terahertz devices.

| S-EPMC6059931 | biostudies-literature

Independent controls of differently-polarized reflected waves by anisotropic metasurfaces.

Project description:We propose a kind of anisotropic planar metasurface, which has capacity to manipulate the orthogonally-polarized electromagnetic waves independently in the reflection mode. The metasurface is composed of orthogonally I-shaped structures and a metal-grounded plane spaced by a dielectric isolator, with the thickness of about 1/15 wavelength. The normally incident linear-polarized waves will be totally reflected by the metal plane, but the reflected phases of x- and y-polarized waves can be controlled independently by the orthogonally I-shaped structures. Based on this principle, we design four functional devices using the anisotropic metasurfaces to realize polarization beam splitting, beam deflection, and linear-to-circular polarization conversion with a deflection angle, respectively. Good performances have been observed from both simulation and measurement results, which show good capacity of the anisotropic metasurfaces to manipulate the x- and y-polarized reflected waves independently.

| S-EPMC4397642 | biostudies-other

Shaping 3D Path of Electromagnetic Waves Using Gradient-Refractive-Index Metamaterials.

Project description:An all-dielectric semispherical lens with functions in shaping 3D wave-propagation paths is proposed and experimentally verified. When radiation sources are placed in the central region, the lens behaves as a magnifying device to resolve the sources in subwavelength scale; while when the electromagnetic waves impinge on the semispherical lens from outside, they will be guided spirally inward.

| S-EPMC5115487 | biostudies-literature

Fano resonances from gradient-index metamaterials.

Project description:Fano resonances - resonant scattering features with a characteristic asymmetric profile - have generated much interest, due to their extensive and valuable applications in chemical or biological sensors, new types of optical switches, lasers and nonlinear optics. They have been observed in a wide variety of resonant optical systems, including photonic crystals, metamaterials, metallic gratings and nanostructures. In this work, a waveguide structure is designed by employing gradient-index metamaterials, supporting strong Fano resonances with extremely sharp spectra. As the changes in the transmission spectrum originate from the interaction of guided modes from different channels, instead of resonance structures or metamolecules, the Fano resonances can be observed for both transverse electric and transverse magnetic polarizations. These findings are verified by fine agreement with analytical calculations and experimental results at microwave, as well as simulated results at near infrared frequencies.

| S-EPMC4728681 | biostudies-literature

Applications of gradient index metamaterials in waveguides.

Project description:In this letter, we find that gradient index metamaterials (GIMs) could be utilized to manipulate wave propagation in waveguides. Through manipulating the conversion between propagating wave and surface wave, we can design some interesting applications in waveguides, such as controlling transmission effect, realizing bending waveguide and achieving waveguide splitting effect. These devices not only work for both transverse electric and magnetic polarized waves, but also function for a broadband of spectra. Numerical simulations are performed to verify our findings.

| S-EPMC4677397 | biostudies-literature

Conical Refraction of Elastic Waves by Anisotropic Metamaterials and Application for Parallel Translation of Elastic Waves.

Project description:Conical refraction, which is quite well-known in electromagnetic waves, has not been explored well in elastic waves due to the lack of proper natural elastic media. Here, we propose and design a unique anisotropic elastic metamaterial slab that realizes conical refraction for horizontally incident longitudinal or transverse waves; the single-mode wave is split into two oblique coupled longitudinal-shear waves. As an interesting application, we carried out an experiment of parallel translation of an incident elastic wave system through the anisotropic metamaterial slab. The parallel translation can be useful for ultrasonic non-destructive testing of a system hidden by obstacles. While the parallel translation resembles light refraction through a parallel plate without angle deviation between entry and exit beams, this wave behavior cannot be achieved without the engineered metamaterial because an elastic wave incident upon a dissimilar medium is always split at different refraction angles into two different modes, longitudinal and shear.

| S-EPMC5577280 | biostudies-literature

Broadband mode conversion via gradient index metamaterials.

Project description:We propose a design for broadband waveguide mode conversion based on gradient index metamaterials (GIMs). Numerical simulations demonstrate that the zeroth order of transverse magnetic mode or the first order of transverse electric mode (TM0/TE1) can be converted into the first order of transverse magnetic mode or the second order of transverse electric mode (TM1/TE2) for a broadband of frequencies. As an application, an asymmetric propagation is achieved by integrating zero index metamaterials inside the GIM waveguide.

| S-EPMC4838908 | biostudies-other

Enhanced flexural wave sensing by adaptive gradient-index metamaterials.

Project description:Increasing sensitivity and signal to noise ratios of conventional wave sensors is an interesting topic in structural health monitoring, medical imaging, aerospace and nuclear instrumentation. Here, we report the concept of a gradient piezoelectric self-sensing system by integrating shunting circuitry into conventional sensors. By tuning circuit elements properly, both the quality and quantity of the flexural wave measurement data can be significantly increased for new adaptive sensing applications. Through analytical, numerical and experimental studies, we demonstrate that a metamaterial-based sensing system (MBSS) with gradient bending stiffness can be designed by connecting gradient negative capacitance circuits to an array of piezoelectric patches (sensors). Furthermore, we demonstrate that the proposed system can achieve more than two orders of magnitude amplification of flexural wave signals to overcome the detection limit. This research encompasses fundamental advancements in the MBSS with improved performance and functionalities, and will yield significant advances for a range of applications.

| S-EPMC5066180 | biostudies-literature

Electrical access to critical coupling of circularly polarized waves in graphene chiral metamaterials.

Project description:Active control of polarization states of electromagnetic waves is highly desirable because of its diverse applications in information processing, telecommunications, and spectroscopy. However, despite the recent advances using artificial materials, most active polarization control schemes require optical stimuli necessitating complex optical setups. We experimentally demonstrate an alternative-direct electrical tuning of the polarization state of terahertz waves. Combining a chiral metamaterial with a gated single-layer sheet of graphene, we show that transmission of a terahertz wave with one circular polarization can be electrically controlled without affecting that of the other circular polarization, leading to large-intensity modulation depths (>99%) with a low gate voltage. This effective control of polarization is made possible by the full accessibility of three coupling regimes, that is, underdamped, critically damped, and overdamped regimes by electrical control of the graphene properties.

| S-EPMC5621972 | biostudies-literature

Gradient Index Devices for the Full Control of Elastic Waves in Plates.

Project description:In this work, we present a method for the design of gradient index devices for elastic waves in plates. The method allows the design of devices to control the three fundamental modes, despite the fact that their dispersion relation is managed by different elastic constants. It is shown that by means of complex graded phononic crystals and thickness variations it is possible to independently design the three refractive indexes of these waves, allowing therefore their simultaneous control. The effective medium theory required for this purpose is presented, and the method is applied to the design of the Luneburg and Maxwell lenses as well as to the design of a flat gradient index lens. Finally, numerical simulations are used to demonstrate the performance of the method in a broadband frequency region.

| S-EPMC4830996 | biostudies-other

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data