Reflection and transmission of an ultrashort electromagnetic pulse incident normal to a flat plasma layer

The process of reflection and transmission of ultrashort pulses incident normal to a flat plasma layer of finite thickness and on a step barrier is calculated within an exact mathematical approach for various parameters (barrier width and duration and carrier frequency of a corrected Gaussian pulse) of the problem.     

Excitation of Highly Charged Ions in Plasma by Ultrashort Electromagnetic Pulses

Excitation of highly charged ions in plasmas under the action of ultrashort electromagnetic pulses is investigated theoretically in the frame of perturbation theory. The study is based on analytical expression for probability of bound‐bound transition which is derived for Gaussian pulse and Doppler broadening of spectral line shape of the transition. Electronic transitions from the ground state of hydrogen‐like ions are considered with account for fine splitting of upper energy levels. The main attention is paid to the dependence of the excitation probability on pulse duration for various ion charges and carrier frequencies of the pulse. The results obtained are of interest for plasma diagnostics based on ion excitation from ground state by ultrashort pulses. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Elastic Scattering of Ultrashort Laser Pulses on Noble Gas Atoms

Russian Physics Journal - The work deals with a theoretical investigation of elastic scattering of ultrashort electromagnetic pulses (USP) on the noble gas atoms in the far ultra-violet and soft...     

Statistical Models in Theory of Polarization Bremsstrahlung

Universal relations have been derived to describe the spectral-angular dependence of the polarization bremsstrahlung of a fast charged particle, based on a statistical model for the electron skeleton of the target. Three statistical atomic models are considered in terms of which the target characteristics that determine the cross section for polarization bremsstrahlung are calculated and analyzed.     

Attosecond Dynamics of Photoexcitation of the Hydrogen Atom by Ultrashort Laser Pulses

The dynamics of photoexcitation of the hydrogen atom in the discrete and continuous spectra under the action of laser pulses in the attosecond range of time and pulse durations has been analyzed using perturbation theory. It is shown that over time interval shorter than or on the order of pulse duration, the time dependence of the photoexcitation probability is generally oscillating by nature. It has been established that for certain values of parameters, the envelope of this dependence has a peak, the position of which is determined by the pulse duration and carrier frequency.     

Resonant Scattering of Picosecond Laser Pulses by Atoms in Alkali Metal Vapors

Resonant scattering of ultrashort laser pulses (ULPs) in the vicinity of spectral doublets in monatomic lithium and sodium vapors is studied theoretically. The scattering probability over the entire time of pulse action is calculated as a function of various parameters of the problem (carrier frequency and ULP duration, as well as vapor pressure and temperature). It is shown that the dependence of the total scattering probability on the pulse duration is generally nonlinear by nature.     

Phase control of excitation of NV centers in diamond by ultra-short laser pulses

This Letter is a theoretical investigation of the excitation of NV centers in diamonds under ultra-short laser pulses with variable parameters. Calculations are based on the two-level approximation and Bloch formalism using dimensionless variables. The dependency of excitation probability on the carrier-envelope phase was examined for various values of electric field strength and pulse duration.     

Calculation of the probability of photoprocesses induced by ultrashort electromagnetic pulses

An expression for the total probability of photoprocesses induced by ultrashort electromagnetic pulses in terms of the excited transition cross-section has been derived by using perturbation theory. The expression obtained is valid for any radiation spectral width and for various types of transition: bound-bound and bound-free. By way of illustration the excitation of a two-level system by an ultrashort pulse with a controlled carrier–envelope phase and the photoionization of a hydrogen atom under the action of a sequence of two-cycle electromagnetic pulses are considered.