The enhancement of optical characteristics at optical frequencies deviates with the choice of the arrangement of core-shell nanoparticles and their environment. Likewise, the arrangements of core-shell nanoparticles in the air over a substrate or in liquid solution makes them unstable in the atmosphere. This article suggests designing a configuration of an active spherical coated nanoparticle antenna and its extended array in the presence of a passive dielectric, which is proposed to be extendable to construct larger arrays.
View Article and Find Full Text PDFThis article reports the finding of the plasmonic induced polarization rotation and propagation rotation when the plane EM wave radiates the adjacent active coated nano particle and large dielectric sphere at resonant frequency. The results investigate that the incident electromagnetic planewave excites the TM mode in the large size dielectric sphere at first, which affects the TM mode field from the coated nano particle. Consequently, when the combined active coated nano particle and large dielectric sphere are in resonant, the main E-field polarization direction becomes parallel to the propagation direction of the original planewave and main beam of the pattern becomes omnidirectional i.
View Article and Find Full Text PDFA subwavelength water metamaterial is proposed and analyzed for ultra-broadband perfect absorption at microwave frequencies. We experimentally demonstrate that this metamaterial shows over 90% absorption within almost the entire frequency band of 12-29.6 GHz.
View Article and Find Full Text PDFWe design an ultrathin water-based metasurface capable of coherent perfect absorption (CPA) at radio frequencies. It is demonstrated that such a metasurface can almost completely absorb two symmetrically incident waves within four frequency bands, each having its own modulation depth of metasurface absorptivity. Specifically, the absorptivity at 557.
View Article and Find Full Text PDFWe design a new kind of metamaterial absorber in the form of an ultrathin silicon nanostructure capable of having wideband absorption of visible light. We show that our metamaterial can exhibit almost perfect absorption of incident light even though its thickness is several tens of times smaller than the optical wavelength. The combination of two resonant modes in a single nanostructure allows us to achieve absorptivities exceeding 80% in a wide band spanning from 437.
View Article and Find Full Text PDFRecently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams are of complicated structure and very high cost. This paper provides an effective solution of generating dual circularly-polarized (CP) dual-mode OAM beams.
View Article and Find Full Text PDFRecently, vortex beam carrying orbital angular momentum (OAM) for radio communications has attracted much attention for its potential of transmitting multiple signals simultaneously at the same frequency, which can be used to increase the channel capacity. However, most of the methods for getting multi-mode OAM radio beams remain up to now mainly at simulation level, since their implementations are of complicated structure and very high cost. This paper provides an effective design of generating five-mode OAM radio beams by using the Rotman lens-fed antenna array.
View Article and Find Full Text PDF