Near-field polarization conversion in planar chiral nanostructures

Enantiomeric-sensitive optical polarization conversion has been observed in the near-field above a planar chiral nanostructures consisting of an array of gammadions cut in a metal film. Formation of the far-field scattered light rotated with respect to the incident linear polarized light has been visualized

Metamaterial with polarization and direction insensitive resonant transmission response mimicking electromagnetically induced transparency

We report on a planar metamaterial, the resonant transmission frequency of which does not depend on the polarization and angle of incidence of electromagnetic waves. The resonance results from the excitation of high-Q antisymmetric trapped current mode and shows sharp phase dispersion characteristic to Fano-type resonances of the electromagnetically induced transparency phenomenon

Polarization switching and nonreciprocity in symmetric and asymmetric magnetophotonic multilayers with nonlinear defect

A one-dimensional magnetophotonic crystal with a nonlinear defect placed either symmetrically or asymmetrically inside the structure is considered. Simultaneous effects of time-reversal nonreciprocity and nonlinear spatial asymmetry in the structure are studied. Bistable response is demonstrated in a such system, accompanied by abrupt polarization switching between two circular or elliptical polarizations for transmitted and reflected waves. The effect is explained in terms of field localization at defect-mode spectral resonances and can be used in the design of thin-film optical isolators and polarization transformation devices.Comment: 20 pages, 8 figure

Cooperative resonance linewidth narrowing in a planar metamaterial

We theoretically analyze the experimental observations of a spectral line collapse in a metamaterial array of asymmetric split ring resonators [Fedotov et al., Phys. Rev. Lett. 104, 223901 (2010)]. We show that the ensemble of closely-spaced resonators exhibits cooperative response, explaining the observed system-size dependent narrowing of the transmission resonance linewidth. We further show that this cooperative narrowing depends sensitively on the lattice spacing and that significantly stronger narrowing could be achieved in media with suppressed ohmic losses.Comment: 19 pages, 6 figures, to appear in New Journal of Physic

Effect of rotary swaging on the structure, mechanical characteristics and aging behavior of Cu-0.5%Cr-0.08%Zr alloy

A study of the effect of rotary swaging on the microstructure and properties of the pre-extruded and pre-quenched Cu-0.5%Cr-0.08%Zr alloy was performe

Photonic band gaps in complex layered arrays, Journal of Telecommunications and Information Technology, 2001, nr 4

Reflective and transmitting properties of several layers of double-periodic arrays are studied. In the arrays, elements are conducting inclusions of various shapes. It is shown that in these structures all the phenomena recently found in dense wire grids with periodical defects (so-called photonic band gap structures) can be observed and explained in simple terms of inter-layer and inclusion resonances. Frequency-selective (with two and more stop bands) and polarization transformation properties of these arrays are demonstrated

Optical Spectroscopy of the Nd3+Nd^{3+} Luminescence Centres in the Sr4B14O25:NdSr_{4}B_{14}O_{25}:Nd Crystal

Optical absorption, emission and luminescence kinetics of $Nd^{3+}$ centres in the new borate crystal with $Sr_{4}B_{14}O_{25}:Nd$ (Nd content 0.2 wt.%) composition are investigated and analysed. The oscillator strengths ($P_\text{theor}$ and $P_\text{exp}$) for observed absorption transitions and phenomenological intensity parameters $Ω_t$ ($Ω_2$=1.59×$10^{-20} cm^{-1}$, $Ω_{4}$ = 2.06 × $10^{-20} cm^{-1}$, and $Ω_{6}$ = 2.28 × $10^{-20} cm^{-1}$ were calculated based on the standard Judd-Ofelt theory. Using $Ω_t$ parameters the radiative transitions rates $(W_{r})$, branching ratios (β) and radiative lifetime $(τ_{rad})$ for $Nd^{3+}$ centres in the $Sr_{4}B_{14}O_{25}:Nd$ crystal were calculated and analysed. Measured lifetime ($τ_{exp}$ = 105 and 93 μs at T = 10 and 300 K, respectively) is compared with this calculated ($τ_{rad}$ = 331 μs) and quantum efficiency for $Nd^{3+}$ centres from $\text{}^{4}F_{3//2}$ emitting level in the $Sr_{4}B_{14}O_{25}:Nd$ crystal is estimated (η ≅ 30%). Incorporation peculiarities and local structure of $Nd^{3+}$ luminescence centres in the $Sr_{4}B_{14}O_{25}$ crystal and corresponding glass with $4SrO-7B_{2}O_{3}$ composition are discussed on the basis of referenced X-ray diffraction data and presented results

Optical Spectroscopy of the Nd 3+

Optical absorption, emission and luminescence kinetics of $Nd^{3+}$ centres in the new borate crystal with $Sr_{4}B_{14}O_{25}:Nd$ (Nd content 0.2 wt.%) composition are investigated and analysed. The oscillator strengths ($P_\text{theor}$ and $P_\text{exp}$) for observed absorption transitions and phenomenological intensity parameters $Ω_t$ ($Ω_2$=1.59×$10^{-20} cm^{-1}$, $Ω_{4}$ = 2.06 × $10^{-20} cm^{-1}$, and $Ω_{6}$ = 2.28 × $10^{-20} cm^{-1}$ were calculated based on the standard Judd-Ofelt theory. Using $Ω_t$ parameters the radiative transitions rates $(W_{r})$, branching ratios (β) and radiative lifetime $(τ_{rad})$ for $Nd^{3+}$ centres in the $Sr_{4}B_{14}O_{25}:Nd$ crystal were calculated and analysed. Measured lifetime ($τ_{exp}$ = 105 and 93 μs at T = 10 and 300 K, respectively) is compared with this calculated ($τ_{rad}$ = 331 μs) and quantum efficiency for $Nd^{3+}$ centres from $\text{}^{4}F_{3//2}$ emitting level in the $Sr_{4}B_{14}O_{25}:Nd$ crystal is estimated (η ≅ 30%). Incorporation peculiarities and local structure of $Nd^{3+}$ luminescence centres in the $Sr_{4}B_{14}O_{25}$ crystal and corresponding glass with $4SrO-7B_{2}O_{3}$ composition are discussed on the basis of referenced X-ray diffraction data and presented results

LEONID M. LYTVYNENKO, AN OUTSTANDING SCIENTIST AND RESEARCH MANAGER (Editorial)

This paper is an attempt of paying tribute to the memory of Leonid Mykolayovych Lytvynenko (LML), an outstanding Ukrainian scientist, Full Member of the National Academy of Sciences who worked most fruitfully in the fields of radio science and radio astronomy. Starting of 1985, Dr. Lytvynenko was, over a 30-plus years period, at the head of the Institute of Radio Astronomy, Acad. Sci. of the Ukrainian SSR (currently the National Academy of Sciences of Ukraine) that had been established owing to his vigorous and direct participation in the process. In 1996 LML promoted foundation of a new scientific journal, namely the "Radio Physics and Radio Astronomy", which he devotedly served for, in the Editor-in-Chief capacity, during the 25 years that followed. Dr. L. Lytvynenko was one of the brightest representatives of the school of theoretical radio physics that had developed within the O. Usikov Institute for Radio Physics and Electronics in Kharkiv and further flourished within the Institute of Radio Astronomy. He is known as the founder of a new branch of radio science, specifically theory of electromagnetic wave diffraction and propagation through composite and multilayered periodic structures