Vector beams, with a spatial nonuniform polarization distribution, are important for many applications due to their unique field characteristics and novel effects when interacting matter. Here, through three-dimensional particle-in-cell simulations, we demonstrate that intense vector beams in the extreme-ultraviolet x-ray spectral region can be generated by means of high harmonic generation (HH...

The interaction of the intense laser pulse, which forms basis strong field and non-linear optical physics, with atoms, molecules, solids leads to High Order Harmonic Generation (HHG). There are many theoretical experimental research related this process defined by Semi-Classic Model is called Three Step Model. In article, dipole non-dipole effects specified in Lewenstein model be used Argon ato...

We numerically solved the full-dimensional electronic time-dependent Schrödinger equation for H2+ with Born-Oppenheimer approximation under different sin2-shaped and trapezoidal laser pulses at some wavelengths, I = 1 × 1013, 3 1013 6 Wcm−2 intensity 4.73 a.u. 7.0 internuclear distances. Some structures such as minima oscillatory patterns appearing in high-order harmonic generation (HHG) spectr...

where 2 = 0.03 and 2e = 1.0 are softening parameters. Here we have neglected the terms related to the small ratio of the electron mass to that of the nuclei. For cases of mass-scaled H2 with mass of hydrogen of Mp = 1836 and heavier, considered in this paper, this approximation leads to unnoticeable differences in the calculated HHG spectra. The interaction between the molecule and a laser fiel...

High-order harmonic generation (HHG) in gases leads to short-pulse extreme ultraviolet (XUV) radiation that is useful a number of applications, such as attosecond science and nanoscale imaging. However, this process depends on many parameters, there still no consensus how choose the target geometry optimize source efficiency. We review physics HHG with emphasis macroscopic aspects nonlinear int...

We numerically solved the full-dimensional electronic time-dependent Schrödinger equation for H2+ with Born-Oppenheimer approximation under different sin2-shaped and trapezoidal laser pulses at some wavelengths, I = 1 × 1013, 3 1013 6 Wcm−2 intensity 4.73 a.u. 7.0 internuclear distances. Some structures such as minima oscillatory patterns appearing in high-order harmonic generation (HHG) spectr...

The theory of photoionization describing the interaction x-ray free-electron laser (XFEL) pulses and high-harmonic-generated (HHG) radiation is generalized to ultrashort pulses, where concept standard ionization probability per unit time in Fermi’s golden rule Einstein’s breaks down. Numerical calculations carried out terms a for total duration near-threshold regime demonstrate essentially nonl...

High-order harmonic generation (HHG) from crystals is emerging as a new ultrashort source of coherent extreme ultraviolet (XUV) light. Doping the crystal structure can offer way to control properties. Here, we present study HHG enhancement in XUV spectral region an ionic crystal, using dopant-induced vacancy defects, driven by laser centered at wavelength 1.55 μm. Our numerical simulations base...

We propose an analytical approach to high-harmonic generation (HHG) for nonperturbative low-frequency and high-intensity fields based on the (Jeffreys-)Wentzel-Kramers-Brillouin (WKB) approximation. By properly taking into account Stokes phenomena of WKB solutions, we obtain wavefunctions that systematically include repetitive dynamics production acceleration electron-hole pairs quantum interfe...