arXiv subjects

I. S. Spevak

Publications and source records attributed to I. S. Spevak.

3 recordsLinked to original sources

arXiv2018

Resonance nonlinear reflection from neutron star and additional radiation components of Crab pulsar

Additional high-frequency components of the pulsar radiation in Crab Nebula are considered as a result of the resonance with the surface electromagnetic wave at nonlinear reflection from of the neutron star surface.This stimulated scattering consists in generation of a surface periodic relief by an incident field and diffraction on that relief the radiation of relativistic positrons, which fly from the magnetosphere to the star in the accelerating electric field of a polar gap.

astro-ph.HE↗

arXiv2013

Surface plasmon-polariton resonance at diffraction of THz radiation on semiconductor gratings

Resonance diffraction of THz HCN laser radiation on a semiconductor (InSb) grating is studied both experimentally and theoretically. The specular reflectivity suppression due to the resonance excitation of the THz surface plasmon-polariton is observed on a pure semiconductor grating and on semiconductor gratings covered with a thin striped layer of the residual photoresist. Presence of a thin dielectric layer on the grating surface leads to the shift and widening of the plasmon-polariton resonance. A simple analytical theory of the resonance diffraction on a shallow grating covered with a dielectric layer is presented. Its results are in a good accordance with the experimental data. Analytical expressions for the resonance shift and broadening can be useful for sensing data interpretation.

physics.optics↗

arXiv2008

Resonantly suppressed transmission and anomalously enhanced light absorption in ultrathin metal films

We study light diffraction in the periodically modulated ultrathin metal films both analytically and numerically. Without modulation these films are almost transparent. The periodicity results in the anomalous effects, such as suppression of the transmittance accompanied by a strong enhancement of the absorptivity and specular reflectivity, due to excitation of the surface plasmon polaritons. These phenomena are opposite to the widely known enhanced transparency of periodically modulated optically thick metal films. Our theoretical analysis can be a starting point for the experimental investigation of these intriguing phenomena.

cond-mat.other↗