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In this study we describe the design, the simulation and the characterization of a NIR domain plasmonic wavelength demultiplexer integrated on SOI waveguide. The reported device is made of a few chains of gold nano cut wires with a total feature dimensions of 4μm×4μm and is acting as a 1.3/1.5 μm wavelength demultiplexer for optical communication. This is the smallest footprint size wavelength demultiplexer...
We demonstrate numerically and experimentally the feasibility of an ultra-thin invisibility cloak for low frequency antenna applications. We consider a monopole antenna mounted on a ground plane and a metallic obstacle located in its near-field. We simulate the real antenna radiation scenario considering the finite size of the obstacle, its cylindrical form, as well as the non-negligible influence...
A planar reconfigurable metasurface is used as a parabolic reflector for antenna applications. The metasurface is composed of unit cells incorporating voltage-controlled varactor diodes, where the dispersion responses of the cells can be tailored. The phase characteristics of a parabolic reflector is engineered by judiciously controlling the bias voltage of the varactor diodes on the planar metasurface...
We introduce a novel class of dark modes for electromagnetically induced transparency. These dark modes depend on both near-field and far-field coupling between resonators. As an example, a planar metasurface composed of a bilayer of metallic Z-shaped meta-atoms is investigated. Performed simulations and measurements show the appearance of sharp Fano resonances.
An active metasurface is used as a reconfigurable reflectarray antenna. The metasurface is composed of unit cells incorporating voltage-controlled varactor diodes, where the dispersion responses of the cells can be tailored. A prototype is fabricated and far-field antenna measurements are performed. We experimentally demonstrate frequency agility over a broad frequency range and beam scanning mechanisms.
Superluminal wave propagation phenomenon achieved from a periodic structure in which a transmission line (TL) is loaded with non-Foster negative capacitors is presented. The loading decreases the effective capacitance and the effective permittivity of the dielectric substrate of the TL. An experimental investigation of the superluminal phase and group velocity in the non-Foster loaded TL is reported...
To create an active phase-gradient metasurface relying on variable inductance, an impedance converter is used to realise positive inductance values. By varying the inversion coefficient, a variation of the inductance can be achieved electronically. A prototype of the circuit is fabricated and tested. Different inductance values are obtained with respect to the inversion coefficient used. Such circuit...
All-dielectric devices are designed using Quasi-Conformal Transformation Optics (QCTO) concept and fabricated by additive manufacturing for the control of wave propagation. Three lenses are studied; the first one is used to compensate for the curvature of a non-planar antenna array, the second one to steer an electromagnetic beam and the last one to concentrate an electromagnetic field.
The engineering of metasurfaces for antenna and sensing applications is studied. The metasurfaces composed of LC-resonant cells, are designed to achieve either phase modulation or high quality factor resonances. While the phase modulated metasurface used as a superstrate in a Fabry-Perot cavity antenna, shows the capability to steer the radiated beam to an off-normal radiation, the high quality factor...
in this study we describe the design, the simulation and the characterization of a waveguided plasmonic lens on SOI. The lens is made of gold nanowires on a SOI waveguide. A thin silicon dioxide layer separates the gold nanowires from the SOI waveguide. This lens is made of a gradient index corresponding to the effective index of the gold wires on the silicon waveguide. Simulations and characterizations...
A miniaturized antenna using a matching circuit with Non-Foster elements is described. Such active external matching circuit allows a commercial antenna whose frequency range is 950–1260 MHz to operate at lower frequencies (about 125 MHz) with a relative bandwidth of 40%. Analytical study was used to design the active circuit and then to implement it. Simulation and measurement results show similar...
Quasi-conformal transformation optics (QCTO) is applied to design electromagnetic lenses for focusing and collimating applications at microwave frequencies. Two devices are studied and conceived by solving the Laplace's equation that describes the deformation of a medium in a space transformation. The first lens is applied to produce an overall directive in-phase emission from an array of sources...
Based on transformation electromagnetics concept, the design procedure of a lens antenna, which steers the radiated beam of a primary source, is presented. Laplace's equation is adopted to construct the mapping between the virtual space and the physical space. Full wave simulations are performed to validate the model. The numerical results show that, when placing the lens antenna above a microstrip...
It has been recently shown that a metasurface presenting a phase-gradient can be effectively used as a partially reflecting surface (PRS) in a Fabry-Perot leaky wave antenna to produce beam steering. The aim of the present contribution is to develop and present an analytical model which will allow us to predict the angle of deflection.
In this paper, based on quasi-conformal transformation optics (QCTO), a synthesis design of a conformal array radiation enhanced by an all-dielectric metamaterial lens is presented. For the two-dimensional TE polarization, a physically cylindrically conformed patch array can acquire the same radiating features of a virtual planar focusing patch array, using a lens having only nonmagnetic medium parameters...
Transformation optics concept is used to change the physical size of radiating sources. By choosing transformations that either compress or expand space, and then match it to the surrounding radiation environment, we are able to either increase or reduce the aperture size of the embedded source. We show that a small aperture antenna can then behave as one with a large aperture and vice-versa. A study...
A planar Z-shaped meta-atom has been recently proposed as an alternative design to the conventional electric-LC (ELC) resonator for achieving negative permittivity. Transforming the LC topology of the resonator helps to facilitate transposition of geometrical parameters for the optical regime and also to improve the metamaterial homogeneity. In this work, we discuss about the interpretation of the...
Gradient index lenses are proposed to transform a cylindrical wave into a plane one. The lenses are designed from metamaterials engineering in a wide frequency band. A primary source operating in the whole X-band is used to feed the lenses. The lens-antenna systems are low profile and exhibit a directive emission in the H-plane. A very good agreement is observed between measurements performed on the...
We address the potential of a metamaterials in a guided wave configuration for applications in the near IR domain. We consider a hybrid type structure made of 2D metamaterial array over a high index slab waveguide, as for instance silicon our case. The experimental and modeling results show that effective index and loss level in such hybrid waveguides can be carefully controlled by the engineering...
In this paper we address the potential of metallic metamaterials in guided wave configurations to explore the possibility of their use for transformation optics applications in the near-infrared domain (λ = 1.5 µm). The experimentally investigated hybrid metamaterial structure is made of 2D array of 200×50×50 nm gold cut wires located on the top of high index silicon on insulator (SOI) waveguide....
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