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We present results of first experiments with elementary cells for detection of sub-millimeter-wave radiation. The cells realize frequency-division multiplexing (FDM) readout of an antenna coupled superconducting hot electron bolometers (HEB) by means of integrated GHz-range superconducting resonators. Such cells can be coupled to a single transmission line for FDM readout, forming a large format imaging...
We propose a general method to synthesize metasurfaces based on a polarizability-susceptibility scattering approach. We show that a minimal set of four non-zero effective electric and magnetic susceptibility tensor components is sufficient to theoretically transform an incident electromagnetic wave into a great diversity of transmitted and/or reflected waves, where the metasurface can provide positive...
Comprehensive simulations are employed to study the interaction between Laguerre-Gaussian (LG) beams and chiral clusters made of silicon nano-spheres. It is demonstrated that the scattering process is strongly dependent on the orbital and spin angular momentum carried by the LG beams, an effect explained by the selective suppression or resonantly enhanced excitation of Mie modes of the spheres. We...
In this paper we report on techniques to improve sensitivity and reduce the residual stress and its effects on THz MEMS bi-material sensors, using metamaterial structures and self-leveling configurations. Structural metamaterial films made of aluminum and silicon-rich silicon oxide bring the THz absorption close to 100% while making the absorption area relatively flat. Multi-folded bi-material and...
The present work introduces the explicit modelling of graphene in the time domain, defined by its surface conductivity, as a surface boundary condition via an efficient 2D transverse electric FDTD formulation, derived directly from Maxwell's equations. The analysis is conducted at the far-infrared regime and the proposed method is validated by comparing its results with the theoretical propagation...
The link between the constitutive parameters of dissipative media supporting (un)usual wave motions and the plane wave motion exhibition, has been established in order to propose a tool for designing functional materials able to control acoustic wave propagation. In this context, we propose a new route to produce a large amount of Mie resonators possessing very low sound speed (100 m s−1) by means...
The performance/robustness of metasurface cloaks to a complex field environment which may represent a realistic scenario of radiating sources is presently reported. Attention is devoted to the cloak operation near-by multiple line sources and multiple perfectly electrically conducting cylinders. It is shown that the metasurface cloaks, initially designed to cloak an isolated dielectric cylinder excited...
Here, we investigate the performance of metasurfaces used for cloaking of cluster configurations formed by different arrangements of multiple dielectric cylinders and excited by an electric line source. While a suitably designed metasurface can be used to effectively cloak isolated electrically small cylinders, we demonstrate that even electrically large clusters of such particles can be cloaked by...
We introduce the concept of non-uniform metamirrors (full-reflection metasurfaces) providing full control of reflected wave fronts independently from the two sides of the mirror. Metamirror is a single planar array of electrically small bianisotropic inclusions. The electric and magnetic responses of the inclusions enable creating controlled gradient of phase discontinuities over the surface. Furthermore,...
In this work, a design of ultra-compact plasmonic modulator is proposed and numerically analyzed. The device layout utilizes alternative plasmonic materials such as transparent conducting oxides and titanium nitride which potentially can be applied for CMOS compatible process. The modulation is obtained by varying the carrier concentration of the transparent conducting oxide layer and exciting plasmonic...
We analyze and compare surface- and volume-based internal photoelectric effects from spherical nanoparticles, obtaining analytical expressions for the photoemission rate in both cases. Similar to results for a flat metal surface, one can show that the surface mechanism prevails, since it is unaffected by detrimental hot electron collisions. Transient absorption results from dielectric permittivity...
An angular bandpass filter is designed. The structure is made of an array of chains of interconnected Split Ring Resonators. It may be applied for increasing directivity of antennas or reducing grating sidelobes. The main advantage over previous angular filters is the smaller thickness of the structure which is a small fraction of the wavelength while previous designs had always a thickness near one...
We have established a set of useful constraints that should be verified by thin metasurfaces made of perfect electric conductor. Mainly, we found that loci of transmission and reflection coefficients on the complex plane are circumferences. The properties shown in this paper may be useful for limiting the types of realistic responses desired for new metasurfaces.
Answering the question-title, probably quasi-duality is possible for isotropic resonators. It has been found that an isotropic cubic resonator and its complementary counterpart have dual polarizability tensors. However, non isotropic cubic resonators are not dual respect to their complementary particles.
In this work a technique for designing linear to circular polarization convertors is proposed. It is based on self-complementary metasurfaces graved on metal sheets. This kind of device can receive a linearly polarized wave and convert it into a circularly polarized wave. The main advantage over previous designs is the theoretical constancy of the phase difference between the transmission (or reflection)...
In this contribution, we extend the recent results obtained by our group concerning the use of metamaterial-inspired inclusions to design self-filtering horn antennas. In particular, we propose a new horn antenna with a notched-band characteristic based on the use of a single split-ring resonator (SRR). From simulated results it can be found that the proposed structure has a notched-band around the...
A novel compact closed complimentary split ring resonator based Electromagnetic Band gap (C-CSRR-EBG) cell is proposed and its compactness is analyzed numerically. A good reduction level of 21 dB is achieved when 11×3 matrix of the proposed unit cell has been applied to enhance the isolation between the E plane coupled patch antenna arrays. This paper also describes about how the proposed structure...
We study the guided modes in the wire medium slab taking into account both the nonlocality and losses in the structure. We show that due to the fact that the wire medium is an extremeley spatially dispersive metamaterial, the effect of nonlocality plays a critical role since it results in coupling between the otherwise orthogonal guided modes. We show that such a structure supports a set of deep subwavelength...
Here, two different THz radiating structures are analyzed, consisting both of a central slot surrounded by annular or straight corrugations. Concentrically grooved antenna presents a moderately high gain. Its radiation and temporal properties are analyzed both numerically and experimentally. For the second case, no appreciable differences in terms of radiation characteristics are observed when the...
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