Related papers: Gradient Index Metamaterial Based on Slot Elements
We propose a general method for designing wideband matching tapers in inhomogeneous media where phase velocity is coupled to the taper impedance profile. Such tapers are used to match wideband gradient index (GRIN) lens antennas. To…
We demonstrate a silicon-based, single-layer anti-reflection coating that suppresses the reflectivity of metals at near-infrared frequencies, enabling optical probing of nano-scale structures embedded in highly reflective surroundings. Our…
The advent of additive manufacturing has opened opportunities to rapidly prototype devices and products ranging from automotive and aerospace applications to micro/nanoscale metastructures, as examples). Three-dimensional (3D) printing has…
We consider some nonlinear phenomena in metamaterials with negative refractive index properties. Our consideration includes a survey of previously known results as well as identification of the phenomena that are important for applications…
Negative refraction is known to occur in materials that simultaneously possess a negative electric permittivity and magnetic permeability; hence they are termed negative index materials. However, there are no known natural materials that…
We theoretically demonstrate the capability of a ferromagnetic-normal (FN) interface in graphene to focus an electron-wave with a certain spin direction. The essential feature is the negative refraction Klein tunneling, which is…
Sub-wavelength resolution imaging requires high numerical aperture (NA) lenses, which are bulky and expensive. Metasurfaces allow the miniaturization of conventional refractive optics into planar structures. We show that high-aspect-ratio…
A metamaterials-based approach to making a wide-angle absorber of infrared radiation is described. The technique is based on an anisotropic Perfectly Impedance Matched Negative Index Material (PIMNIM). It is shown analytically that a…
In this paper we present a novel telescope composed exclusively of thin, flat optical elements, each being a hot-pressed multi-layered structure combining the properties of a lens, its anti-reflection coating and frequency selection or…
We demonstrate the capability of block-copolymer templating to tune the refractive indices of functional oxides over a broad range by structuring materials on the 20-1000 atoms scale, with simple one-pot synthesis. The presented method is…
Novel low index (n less than 1.3)/high light trapping cladding films consisting of nanoporous alumina (sapphire), as formed by controlled anodization of aluminum, are described. These films are mechanically hard, intrinsically very…
The index of refraction governs the flow of light through materials. At visible and near infrared wavelengths the real part of the refractive index is limited to less than 3 for naturally occurring transparent materials, fundamentally…
We found strong similarities between the gravitational lensing and the conventional optical lensing. The similarities imply a graded refractive index description of the light deflection in gravitational field. We got a general approach to…
We designed and implemented a gradient index metasurface for the in-plane focusing of confined terahertz surface waves. We measured the spatial propagation of the surface waves by two-dimensional mapping of the complex electric field using…
Recently, we have suggested dielectric metamaterial composed as an array of submicron dielectric spheres located on top of an amorphous thin-film solar cell. We have theoretically shown that this metamaterial can decrease the reflection and…
We present an apparatus for terahertz fingerprint discrimination of materials designed to be fast, simple, compact and economical in order to be suitable for preliminary on-field analysis. The system working principles, bioinspired by the…
Spectral imagers, the classic example being the color camera, are ubiquitous in everyday life. However, most such imagers rely on filter arrays that absorb light outside each spectral channel, yielding ~1/N efficiency for an N-channel…
Guided mode resonance (GMR), the resonant coupling of free-space light into leaky waveguide modes, is traditionally achieved with periodic patterned structures. However, this approach makes its key properties such as quality factor…
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…
Cost-effective mid-wave infrared (MWIR) optoelectronic devices are of utmost importance to a plethora of applications such as night vision, thermal sensing, autonomous vehicles, free-space communication, and spectroscopy. To this end,…