| 1. |
- Krasnok, A. E., et al.
(author)
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All-Dielectric Nanophotonics: Fundamentals, Fabrication, and Applications
- 2018
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In: World Scientific Series in Nanoscience and Nanotechnology. - : World Scientific. - 2301-301X .- 2335-6693. ; 16, s. 337-385
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Book chapter (other academic/artistic)abstract
- This chapter reviews a novel, rapidly developing field of modern light science named all-dielectric nanophotonics. This branch of nanophotonics is based on the properties of high-index dielectric nanoparticles which allow for controlling both magnetic and electric responses of a nanostructured matter. Here, we discuss optical properties of high-index dielectric nanoparticles, methods of their fabrication, and recent advances in practical applications, including the quantum source emission engineering, Fano resonances in all-dielectric nanoclusters, surface enhanced spectroscopy and sensing, coupled-resonator optical waveguides, metamaterials and metasurfaces, and nonlinear nanophotonics.
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| 2. |
- Krasnok, A. E., et al.
(author)
-
All-Optical Switching and Unidirectional Plasmon Launching with Nonlinear Dielectric Nanoantennas
- 2018
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In: Physical Review Applied. - 2331-7019. ; 9:1
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Journal article (peer-reviewed)abstract
- High-index dielectric nanoparticles have become a powerful platform for nonlinear nanophotonics due to special types of optical nonlinearity, e.g. caused by electron-hole plasma (EHP) photoexcitation. We propose a highly tunable dielectric nanoantenna consisting of a chain of silicon particles excited by a dipole emitter. The nanoantenna exhibits slow group-velocity guided modes, corresponding to the Van Hove singularity in an infinite structure, which enable a large Purcell factor up to several hundred and are very sensitive to the nanoparticle permittivity. This sensitivity enables the nanoantenna tuning via EHP excitation with an ultrafast laser pumping. Dramatic variations in the nanoantenna radiation patterns and Purcell factor caused by ultrafast laser pumping of several boundary nanoparticles with relatively low intensities of about 25 GW/cm2 are shown. Unidirectional surface-plasmon polaritons launching with EHP excitation in the nanoantenna on a Ag substrate is demonstrated.
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| 3. |
- Krasnok, A. E., et al.
(author)
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Coherently Enhanced Wireless Power Transfer
- 2018
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In: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 120:14
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Journal article (peer-reviewed)abstract
- Extraction of electromagnetic energy by an antenna from impinging external radiation is at the basis of wireless communications and wireless power transfer (WPT). The maximum of transferred energy is ensured when the antenna is conjugately matched, i.e., when it is resonant and it has an equal coupling with free space and its load. This condition, however, can be easily affected by changes in the environment, preventing optimal operation of a WPT system. Here, we introduce the concept of coherently enhanced WPT that allows us to bypass this difficulty and achieve dynamic control of power transfer. The approach relies on coherent excitation of the waveguide connected to the antenna load with a backward propagating signal of specific amplitude and phase. This signal creates a suitable interference pattern at the load resulting in a modification of the local wave impedance, which in turn enables conjugate matching and a largely increased amount of extracted energy. We develop a simple theoretical model describing this concept, demonstrate it with full-wave numerical simulations for the canonical example of a dipole antenna, and verify experimentally in both near-field and far-field regimes.
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| 4. |
- Li, S., et al.
(author)
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Coherently enhanced wireless power transfer: Theory and experiment
- 2018
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In: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1092
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Conference paper (peer-reviewed)abstract
- Extraction of electromagnetic energy by an antenna to a coupled waveguide is the crucial part of wireless power transfer. Efficiency of this process is usually defined by the coupling strength between the antenna and the outcoupling waveguide or cable. We show that there is an additional possibility to improve the receiving efficiency by coherent excitation of the outcoupling waveguide by a backward propagating guided mode with a specific amplitude and phase. This additional wave creates a special interference picture in the system and result in increased amount of energy extracted to the waveguide from the free space. We develop a simple analytical model predicting this effect, demonstrate it in numerical FDTD simulations, and verify in microwave experiment.
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