Diffraction of ultrashort pulse on a nanoscale conductive cone

Surface plasmon polariton is collective oscillation of the free electrons at metal dielectric interface. As a wave phenomenon, surface plasmon polaritons can be focused using appropiate excitation geometry of metallic structures. We theoretically demonstrate the possibility of controlling nanoscale short pulse superfocusing based on the generation of radially polarized surface plasmon polariton mode of conical metallic tip. Numerical simulation for femtosecond pulse propagation along a silver nano-needle is discussed. The spatial distribution for a near field strongly depends on a linear chirp of the laser pulse which can partially compensate the wave dispersion. Field distribution is calculated for different chirp values, opening angle 0.1, distances ri = 1000 nm and rf = 250 nm. For a pulse with a chirp β =-0.013 fs1, pulse duration becomes shorter and changes from 32 fs to 18.8 fs, and field amplification is equal to 42.7

Propagation of ultrashort pulses in single-mode fiber

Propagation of ultrashort pulses in dispersing media and optical fibers is calculated and analyzed. An analytical expression for the electric field of ultra short pulse after propagating certain distance z is derived in the second order dispersion theory. The propagation of a Gaussian pulse is considered. ultra-short pulses, optical fiber, dispersion

Excitation of quantum dot by femtosecond plasmon-polariton pulse focused by conducting cone

A surface plasmon polariton is an electromagnetic wave that propagates along an interface between two materials with dielectric permittivity of opposite signs. Such waves can be focused by metal waveguides of special geometry. The spatial distribution for a near-field strongly depends on a linear chirp of the laser pulse, which can partially compensate the wave dispersion. Field distribution is calculated for different chirp values, opening angles, and distances. The spatial selectivity of excitation of quantum dots using focused fields is shown using Bloch equations

Modification of the EDXD method for diagnostics of polycrystalline and fine-grained media

The possibilities of using broadband X rays for diagnostics of the atomic structure of solids are considered. It is proposed to use virtual photons of the Coulomb field of a relativistic electron beam as primary probe radiationye

Multiphoton radiative recombination of electron assisted by laser field

In the presence of an intensive laser field the radiative recombination of the continuum electron into an atomic bound state generally is accompanied by absorption or emission of several laser quanta. The spectrum of emitted photons represents an equidistant pattern with the spacing equal to the laser frequency. The distribution of intensities in this spectrum is studied employing the Keldysh-type approximation, i.e. neglecting interaction of the impact electron with the atomic core in the initial continuum state. Within the adiabatic approximation the scale of emitted photon frequencies is subdivided into classically allowed and classically forbidden domains. The highest intensities correspond to emission frequencies close to the edges of classically allowed domain. The total cross section of electron recombination summed over all emitted photon channels exhibits negligible dependence on the laser field intensity.Comment: 14 pages, 5 figures (Figs.2-5 have "a" and "b" parts), Phys.Rev.A accepted for publication. Fig.2b is presented correctl

Modification of the EDXD Method for Diagnostics of Polycrystalline and Fine-Grained Media

Abstract -The possibilities of using broadband X rays for diagnostics of the atomic structure of solids are considered. It is proposed to use virtual photons of the Coulomb field of a relativistic electron beam as primary probe radiation

ИСПОЛЬЗОВАНИЕ КОМПЬЮТЕРИЗИРОВАННОГО МЕТОДА ИССЛЕДОВАНИЯ СКОРОСТИ РЕАКЦИИ И ТОЧНОСТИ МОТОРИКИ РУК У ПАЦИЕНТОВ С АРТЕРИАЛЬНОЙ ГИПЕРТЕНЗИЕЙ

The results of examination of the motility accuracy and speed in patients with arterial hypertension depending of the arterial hypertension level and cognitive disorders are shown.Приведены результаты оценки скорости реакции и точности моторики рук у пациентов с артериальной гипертензией в зависимости от степени заболевания и наличия когнитивного снижения