We demonstrate a composite medium, based on periodic array of interspaced conducting nonmagnetic split ring resonators and continuous wires, that exhibits frequency region in the microwave regime with simultaneously negative values effective permeability &mgr;(eff)(omega) permittivity varepsilon(eff)(omega). This structure forms "left-handed" for which it has been predicted such phenomena as Doppler effect, Cherenkov radiation, even Snell's law are inverted. It is now possible through...

We present the design for an absorbing metamaterial (MM) with near unity absorbance A(omega). Our structure consists of two MM resonators that couple separately to electric and magnetic fields so as absorb all incident radiation within a single unit cell layer. fabricate, characterize, analyze absorber slightly lower predicted A(omega) 96%. Unlike conventional absorbers, our solely metallic elements. The substrate can therefore be optimized other parameters interest. experimentally...

Abstract The advent of negative index materials has spawned extensive research into metamaterials over the past decade. Metamaterials are attractive not only for their exotic electromagnetic properties, but also promise applications. A particular branch–the metamaterial perfect absorber (MPA)–has garnered interest due to fact that it can achieve unity absorptivity waves. Since its first experimental demonstration in 2008, MPA progressed significantly with designs shown across spectrum, from...

We show that magnetic response at terahertz frequencies can be achieved in a planar structure composed of nonmagnetic conductive resonant elements. The effect is realized over large bandwidth and tuned throughout the frequency regime by scaling dimensions structure. suggest artificial structures, or hybrid structures combine natural materials, play key role devices.

In this Letter we demonstrate, for the first time, selective thermal emitters based on metamaterial perfect absorbers. We experimentally realize a narrow band midinfrared (MIR) emitter. Multiple sublattices further permit construction of dual-band MIR By performing both emissivity and absorptivity measurements, find that agree very well as predicted by Kirchhoff's law radiation. Our results directly demonstrate great flexibility metamaterials tailoring blackbody emission.

We present a metamaterial that acts as strongly resonant absorber at terahertz frequencies. Our design consists of bilayer unit cell which allows for maximization the absorption through independent tuning electrical permittivity and magnetic permeability. An experimental absorptivity 70% 1.3 is demonstrated. utilize only single in propagation direction, thus achieving an coefficient $α$ = 2000 cm$^{-1}$. These metamaterials are promising candidates absorbing elements thermally based THz...

High absorption efficiency is particularly desirable at present for various microtechnological applications including microbolometers, photodectors, coherent thermal emitters, and solar cells. Here we report the design, characterization, experimental demonstration of an ultrathin, wide-angle, subwavelength high performance metamaterial absorber optical frequencies. Experimental results show that peak 88% achieved wavelength ∼1.58 μm, though theoretical give near perfect absorption.

We demonstrate, for the first time, a spatially dependent metamaterial perfect absorber operating in infrared regime. achieve an experimental absorption of 97% at wavelength $6.0\text{ }\ensuremath{\mu}\mathrm{m}$, and our results agree well with numerical full-wave simulations. By using two different sublattices we experimentally demonstrate spatial frequency varying which may have many relevant applications, including hyperspectral subsampling imaging.

Abstract Solar steam generation has been achieved by surface plasmon heating with metallic nanoshells or nanoparticles, which have inherently narrow absorption bandwidth. For efficient light-to-heat conversion from a wider solar spectrum, we employ adiabatic plasmonic nanofocusing to attain both polarization-independent ultrabroadband light and high dissipation loss. Here demonstrate large area, flexible thin-film black gold membranes, multiscale structures of varying nanoscale gaps (0–200...

We present the design, fabrication, and characterization of a metamaterial absorber which is resonant at terahertz frequencies. experimentally demonstrate an absorptivity 0.97 1.6 THz. Importantly, our only $16\text{ }\ensuremath{\mu}\text{m}$ thick, resulting in highly flexible material that, further, operates over wide range angles incidence for both transverse electric magnetic radiation.

Utilizing terahertz time domain spectroscopy, we have characterized the electromagnetic response of a planar array split ring resonators (SRRs) fabricated upon high resistivity GaAs substrate. The measured frequency dependent magnetic and electric resonances are in excellent agreement with theory simulation. For two polarizations, SRRs yield negative (epsilon < 0). We demonstrate, for first time, dynamical control electrical through photoexcitation free carriers An excited carrier density...

We present the theory, design, and realization of a polarization-insensitive metamaterial absorber for terahertz frequencies. Effective-medium theory is used to describe absorptive properties in terms optical constants---a description that has been thus far lacking. From our theoretical approach, we construct device yields over 95% absorption simulation. Our fabricated design consists planar single unit-cell layer reaches an absorptivity 77% at 1.145 THz.

We present experimental demonstration of electronically tunable metamaterial perfect absorbers in the terahertz regime. By incorporation active liquid crystal into strategic locations within unit cell we are able to modify absorption by 30 percent at 2.62 THz, as well tune resonant over 4 bandwidth. Numerical full-wave simulations match experiments and clarify underlying mechanism, i.e. a simultaneous tuning both electric magnetic response that allows for preservation absorption. These...

We demonstrate THz metamaterials exhibiting either amplitude control, via carrier injection or depletion in the active semiconductor substrate frequency photoexcitation of carriers into semiconducting materials incorporated sub-wavelength metamaterial structure.

We demonstrate reconfigurable anisotropic metamaterials at terahertz frequencies where artificial ``atoms'' reorient within unit cells in response to an external stimulus. This is accomplished by fabricating planar arrays of split ring resonators on bimaterial cantilevers designed bend out plane a thermal observe marked tunability the electric and magnetic as their cells. Our results that adaptive offer significant potential realize novel electromagnetic functionality ranging from detection...

We present the design, fabrication and characterization of a dual band metamaterial absorber which experimentally shows two distinct absorption peaks 0.85 at 1.4 THz 0.94 3.0 THz. The consists electric-field-coupled (ELC) resonator metallic ground plane, separated by an 8 µm dielectric spacer. Fine tuning resonances is achieved individually adjusting each ELC geometry.

Engineered materials composed of designed inclusions can exhibit exotic and unique electromagnetic properties not inherent in the individual constituent components. These artificially structured composites, known as metamaterials, have potential to fill critical voids spectrum where material response is limited enable construction novel devices. Recently, metamaterials that display negative refractive index – a property found any naturally occurring drawn significant scientific interest,...

We present a class of artificial materials that exhibit tailored response to the electrical component electromagnetic radiation. These electric metamaterials are investigated theoretically, computationally, and experimentally using terahertz time-domain spectroscopy. structures display resonant including regions negative permittivity ${ϵ}_{1}(\ensuremath{\omega})&lt;0$ ranging from...

Deep learning has risen to the forefront of many fields in recent years, overcoming challenges previously considered intractable with conventional means. Materials discovery and optimization is one such field, but significant remain, including requirement large labeled datasets one-to-many mapping that arises solving inverse problem. Here we demonstrate modeling complex all-dielectric metasurface systems deep neural networks, using both geometry knowledge underlying physics as inputs. Our...

Planar electric split ring resonator (eSRR) metamaterials and their corresponding inverse structures are designed characterized computationally experimentally utilizing finite element modeling THz time domain spectroscopy. A complementary response is observed in transmission. Specifically, for the eSRRs a decrease transmission at resonance whereas display an increase The frequency dependent effective complex dielectric functions extracted from experimental data and, combination with...

Metamaterial absorbers consisting of metal, metal-dielectric, or dielectric materials have been realized across much the electromagnetic spectrum and demonstrated novel properties applications. However, most utilize metals thus are limited in applicability due to their low melting point, high Ohmic loss thermal conductivity. Other approaches rely on large structures / a supporting substrate as mechanism, thereby realizing absorption volumes. Here we present terahertz (THz) all metasurface...