High harmonic generation (HHG) using waveform-controlled, few-cycle pulses from Ti:sapphire lasers has opened emerging researches in strong-field and attosecond physics. However, the maximum photon energy of attosecond pulses via HHG remains limited to the extreme ultraviolet region. Long-wavelength light sources with carrier-envelope phase stabilization are promising to extend the photon energ...

We study the dependence of the ac Stark shifts of electronic energies on the molecular orientation relative to the polarization direction of an incident intense laser field, using a three-dimensional non-Hermitian Floquet method and H2 + as a model system. Simultaneously, we also study the orientation-dependent high-order harmonic generation HHG and multiphoton ionization MPI . We find that wit...

We present theoretical calculations of high-order-harmonic generation (HHG) from stereoisomers of 1,2dichloroethylene (C2H2Cl2) and 2-butene (C4H8) based on the quantitative rescattering theory. Our results show that the HHG spectra from these cis and trans isomers with intense midinfrared laser pulses are clearly distinguishable, even when the molecules are randomly oriented, in good agreement...

Spin-orbit interactions lead to small energy gaps between the outer-most p1/2 and p3/2 shells of noble gas atoms. Strong-field pulses tunnel-ionize an electron out of either shell resulting in spinorbit-driven hole motion. These hole dynamics affect the HHG yield. However, the spectral shape as well as the angular distribution of the HHG emission is not influenced by spin-orbit coupling. We dem...

We present a theory that incorporates the vibrational degrees of freedom in a high-order harmonic generation (HHG) process with ultrashort intense laser pulses. In this model, laser-induced time-dependent transition dipoles for each fixed molecular geometry are added coherently, weighted by the laser-driven time-dependent nuclear wave packet distribution. We show that the nuclear distribution c...

When High Harmonic Generation (HHG) is considered theoretically within the ideas of the rescattering mechanism, the specifics of initial/final state of the active electron usually attracts little attention. We explore such a specifics related to initial/final bound p-state of the active electron (existing studies concentrated on s-states). The halogen anions and noble gas atoms (except He) prov...

Mutations in the DAX1 gene cause X-linked adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism (HHG). In affected boys, primary adrenal insufficiency occurs soon after birth or during early childhood; HHG is recognized at the expected time of puberty. In this report, we describe the novel phenotype of a man who presented with apparently isolated adrenal insufficiency at 28 years...

We present an ab initio three-dimensional 3D calculation of multiphoton ionization MPI and high-order harmonic generation HHG of the hydrogen molecular ions subject to intense linearly polarized laser pulses. The orientation of the molecular axis with respect to the polarization of the laser field can be arbitrary. The numerical procedure involves the extension of the generalized pseudospectral...

We study high-order harmonic generation (HHG) spectra by a focused truncated Bessel beam versus a Gaussian beam, including macroscopic propagation of the fundamental laser and harmonic fields in the gas medium, with the single-atom-induced dipole response calculated from the recently developed quantitative rescattering theory. We first simulate the HHG spectra of Ar by an 8-fs and 780-nm short ...

We report theoretical investigations of the tomographic procedure suggested by Itatani et al. Nature London 432, 867 2004 for reconstructing highest occupied molecular orbitals HOMOs using high-order harmonic generation HHG . Due to the limited range of harmonics from the plateau region, we found that even under the most favorable assumptions, it is still very difficult to obtain accurate HOMO ...