65 research outputs found
Spin-coated nickel doped cadmium sulfide thin films for third harmonic generation applications
In the current study, different percentages of Nickel (0%, 2%, 4% and 6%) doped CdS thin films have been deposited on glass substrates by the sol-gel spin-coating technique. Before performing the nonlinear optical studies, the structural, morphological and optical properties were examined as a function of Ni doping concentration through the XRD, SEM, AFM and UV–vis spectrometry, respectively. According to the XRD patterns, all films are polycrystalline and the incorporation of Ni does not change qualitatively the crystalline phase of CdS. The Ni doping affects the surface morphology of the CdS thin films which is indicated by scanning electron microscopy and atomic force microscopy images. The band gap was determined via the equation related to the absorption coefficient. It\u27s deduced that the optical band-gap values increased from 2.35 eV to 2.41 eV depending on Ni content. Though, the nonlinear optical properties were determined based on the measurements of the third harmonic generation (THG) using the rotational Maker fringe technique. The results showed that the third order nonlinear optical susceptibilities oscillate between 5.40 × 10−21 m2/V2 for CdS:Ni (2%) and 4.98 × 10−21 m2/V2 for CdS:Ni (6%) while the pure CdS one falls inward, with a value of 5.09 × 10−21 m2/V2
Metasurface beam splitter based on all-dielectric elliptic resonators
© 2017 IEEE. We describe an all-dielectric metasurface, based on elliptic dielectric resonators (EDRs), which is designed to work as a beam splitter at 16.98 GHz. The proposed metasurface refracts electromagnetic incident waves with orthogonal polarizations along two specific directions without reflection
Metasurface Beam Splitter Based On All-Dielectric Elliptic Resonators
We describe an all-dielectric metasurface, based on elliptic dielectric resonators (EDRs), which is designed to work as a beam splitter at 16.98 GHz. The proposed metasurface refracts electromagnetic incident waves with orthogonal polarizations along two specific directions without reflection
Caractérisation des particules issues des gaz d'échappment des véhicules Euro5
SSCI-VIDE+CARE+ABO:BDANational audienceNon
Design of an ultra-wideband and highly-directive photoconductive THz Vivaldi antenna
© 2017 IEEE. This paper presents the design of THz Vivaldi Antenna operating in the frequency band of 0.1-6 THz. An optimized design of the antenna is developed by using the CST software to realize an ultra-wideband impedance match, which ranges from 0.7 to 6 THz, as well as a high directivity level, which varies from 3.8 dBi at 2.5 THz to 7.8 dBi at 6 THz. The antenna gain Gmax is found to be -1.6 dBi at 5.5 THz its efficiency ηmax is 16.3 % at 5.25 THz, both of which are relatively low because of metallic and dielectric losses
Dynamics of quantum-memory assisted entropic uncertainty and entanglement in two-dimensional graphene
We explore the quantum-memory assisted entropic uncertainty (QMA-EU), Jensen-Shannon coherence and entanglement dynamics in a Graphene sheet of disordered electrons in the presence of the intrinsic decoherence. The Graphene sheet containing two sublattices in a two-dimensional honeycomb lattice, which results due to the impurity-potentials interaction of two Dirac points. Entropic uncertainty and logarithmic negativity are used to investigate the generation and preservation of QMA-EU and entanglement under the major factors of Graphene material, including the band structure parameter, the wave numbers as well as the decoherence effect. For the initial uncorrelated two-lattice-point-qubit state, it is found that the lattice-point interactions have high capacity to generated partially/maximally two-lattice-point-qubit entangled and hence the partial/perfect Bob’s ability to guessing the outcome of Alice’s measurement. The increase of the graphite band structure parameter, the wave numbers enhance the generated lattice-point entanglement and Jensen-Shannon coherence, and hence the quantum memory game has a high prediction accuracy. For the intrinsic decoherence, the ability to generate entanglement, Jensen-Shannon coherence. and guessing the Alice’s measurement outcomes weakens. The sudden death-birth phenomenon in the logarithmic-negativity dynamics appears. The increase of the graphite band structure parameter weakens the robustness dynamics against the decoherence effect, while the increase of the wave number operators enhances this robustness. For initial maximally correlated state, the robustness dynamics of the QMA-EU, Jensen-Shannon coherence, and logarithmic-negativity entanglement is very sensitive to the increase of the band structure, wave numbers, and intrinsic decoherence
A Semi-Octagonal 40-Bit High Capacity Chipless RFID Tag for Future Product Identification
This paper presents a unique geometry of a chipless radio frequency identification (RFID) tag for encoding a large number of bits in a very small form factor. The tag geometry consists of semi-octagonal copper strips, sequentially laid on a single side of an ultra-thin substrate. A unique and robust encoding mechanism for the tag identification (ID) is proposed. The operating frequency spectrum of the tag ranges from 3.1 to 10.5 GHz. The tag is compact, having an overall size of 14.5 × 28 mm2. The proposed tag exhibits very high code density of 9.85 bits/cm2 and spectral efficiency of 5.4 bits/GHz. The unique geometric configuration of the proposed tag allows it to encode up to 40 bits of data as an RCS signature. This chipless RFID tag seems to be a potential candidate for a wide range of modern RFID applications
Design of Ultra Wideband Vivaldi Nanoantenna for Solar Energy Collection
International audienc
- …