20 research outputs found
Optical anapoles in nanophotonics and meta-optics
Interference of electromagnetic modes supported by subwavelength photonic
structures is one of the key concepts that underpins the subwavelength control
of light in meta-optics. It drives the whole realm of all-dielectric
Mie-resonant nanophotonics with many applications for low-loss nanoscale
optical antennas, metasurfaces, and metadevices. Specifically, interference of
the electric and toroidal dipole moments results in a very peculiar,
low-radiating optical state associated with the concept of optical anapole.
Here, we uncover the physics of multimode interferences and multipolar
interplay in nanostructures with an intriguing example of the optical anapole.
We review the recently emerged field of anapole electrodynamics explicating its
relevance to multipolar nanophotonics, including direct experimental
observations, manifestations in nonlinear optics, and rapidly expanding
applications in nanoantennas, active photonics, and metamaterials.Comment: 14 pages, 6 figure
Smart Table Based on Metasurface for Wireless Power Transfer
Metasurfaces have been investigated and its numerous exotic functionalities
and the potentials to arbitrarily control of the electromagnetic fields have
been extensively explored. However, only limited types of metasurface have
finally entered into real products. Here, we introduce a concept of a
metasurface-based smart table for wirelessly charging portable devices and
report its first prototype. The proposed metasurface can efficiently transform
evanescent fields into propagating waves which significantly improves the near
field coupling to charge a receiving device arbitrarily placed on its surface
wirelessly through magnetic resonance coupling. In this way, power transfer
efficiency of 80 is experimentally obtained when the receiver is placed at
any distances from the transmitter. The proposed concept enables a variety of
important applications in the fields of consumer electronics, electric
automobiles, implanted medical devices, etc. The further developed
metasurface-based smart table may serve as an ultimate 2-dimensional platform
and support charging multiple receivers.Comment: 8 pages, 7 figure
Magnetic field concentration with coaxial silicon nanocylinders in the optical spectral range
Resonant magnetic energy accumulation is theoretically investigated in the optical and near-infrared regions. It is demonstrated that the silicon nanocylinders with and without coaxial through holes can be used for the control and manipulation of optical magnetic fields, providing up to 26-fold enhancement of these fields for the considered system. Magnetic field distributions and dependence on the parameters of nanocylinders are revealed at the wavelengths of magnetic dipole and quadrupole resonances responsible for the enhancement. The obtained results can be applied, for example, to designing nanoantennas for the detection of atoms with magnetic optical transitions
Evolutionary and genetic algorithms for design of metadevices working on electric dipole resonance
All-dielectric nanophotonics is a rapidly growing field of modern science. Metasurfaces and other planar devices based on all-dielectric nanoparticles lead to manage the light propagation at the nanoscale. Impressive effects such as perfect absorption, invisibility, chirality effects, negative refraction, light focusing in the area with size smaller than wavelength, nano-lasing etc - can be achieved with all-dielectric technologies. While it is needed to use more and more complicated designs for solution of modern nanophotonics' currents tasks, non-classical methods of optimization become relevant. For example, to design reconfigurable metalenses with an additional degree of freedom such as polarizability or temperature dependence, evolutionary or genetic algorithms show their high applicability. In this work, we show a new approach to design metalenses with evolutionary and genetic algorithms. © 2020 IOP Publishing Ltd
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Transmission and reflection features of all-dielectrics metasurfaces with electric and magnetic resonances
The effective multipole decomposition approach is applied to study the optical features of the silicon metasurface in the near-infrared. The spectral regions of perfect transmission and reflection have been analyzed using the Cartesian multipole decomposition. It is shown that transmission peaks appear due to the mutual interaction of multipole moments up to the third order, while reflection peaks are due to the dominant contribution of one of the multipole moments. The results of this work can be broadly applied to design novel metasurfaces, sensors, and optical filters.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
Electromagnetic realization of topological states in one-dimensional arrays of bianisotropic particles
We propose a strategy to realize one-dimensional electromagnetic topologically protected states by modifying on-site properties of particles keeping linear equidistant geometry of the array. Based on the discrete dipole approximation, we demonstrate the existence of non-trivial topology of photonic bands and mapping to the Su-Schrieffer-Heeger model. We investigate the properties of an isolated ceramic disk to optimize its electromagnetic response, namely, the splitting of electric and magnetic dipole resonances due to bianisotropy. Using fullwave simulations we demonstrate the presence of the topological interface state in the microwave spectral range.This work was supported by the Russian Science Foundation (grant No. 16-19-10538). M.A.G.
acknowledges partial support by the Foundation for the Advancement of Theoretical Physics
and Mathematics “Basis”