相关论文: Strong-field approximation for harmonic generation…
High-order harmonic generation in gas targets is a widespread scheme used to produce extreme ultraviolet radiation, however, it has a limited microscopic efficiency. Macroscopic enhancement of the produced radiation relies on…
The selection rules of high harmonic generation (HHG) are investigated using three-dimensional time-dependent density functional theory (TDDFT). From the harmonic spectra obtained with various real molecules and different forms of laser…
Increase of the cut-off value in the high order harmonics generation process is demonstrated for a special case of the driving field composed of several harmonics of a given frequency. It is shown that a moderate, of the order of 20%,…
High-order harmonic generation with bicircular fields - the combination of counter-rotating circularly polarized pulses at different frequencies - results in a series of short-wavelength XUV harmonics with alternating circular…
We present theoretical investigations of high-order harmonic generation (HHG) resulting from the interaction of noble gases with localized surface plasmons. These plasmonic fields are produced when a metal nanoparticle is subject to a…
Harmonic generation by an atom in a laser field is described by the three-step mechanism as proceeding via above-threshold ionization (ATI) followed by the electron propagation in the laser-dressed continuum and the subsequent laser…
In strong field laser physics it is a common practice to use the high-order harmonic cutoff to estimate the laser intensity of the pulse that generates the harmonic radiation. Based on the semiclassical arguments it is possible to find a…
Theoretical approaches to strong field phenomena driven by plasmonic fields are based on the length gauge formulation of the laser-matter coupling. From the theoretical viewpoint it is known there exists no preferable gauge and consequently…
High-order harmonic generation (HHG) in aligned linear molecules can offer valuable information about strong-field interactions in lower-lying molecular orbitals, but extracting this information is difficult for three-dimensional molecular…
We revisit the mechanism of high harmonic generation (HHG) from solids by comparing HHG in laser fields with different ellipticities but constant maximum amplitude. It is shown that the cutoff of HHG is strongly extended in a circularly…
Light-matter interactions within the strong-field regime, where intense laser fields can ionise a target via tunnelling, give rise to fascinating phenomena such as the generation of high-order harmonic radiation (HHG). On the atomic scale,…
High-order sideband generation (HSG), as an analogue of the interband processes in high-harmonic generation (HHG) in solids, is a nonperturbative nonlinear optical phenomenon in semiconductors that are simultaneously driven by a relatively…
New approach to study the spontaneous emission of the atomic system in the presence of the high-intensity laser field is used to study the process of harmonic generation. The analysis is based on the consideration of quantum system…
We present a generic approach for treating the effect of nuclear motion in the high-order harmonic generation from polyatomic molecules. Our procedure relies on a separation of nuclear and electron dynamics where we account for the…
High-harmonic generation is one of the most extreme nonlinear-optical processes observed to date. By focusing an intense laser pulse into a gas, the light-atom interaction that occurs during the process of ionising the atoms results in the…
We study high-order harmonic generation (HHG) resulting from the illumination of plasmonic nanostructures with a short laser pulse. We show that both the inhomogeneities of the local electric field and the confinement of the electron motion…
V.I. Usachenko and S.-I. Chu [Phys. Rev. A {\bf 71}, 063410 (2005)] discuss the molecular strong-field approximation in the velocity gauge formulation and indicate that some of our earlier velocity gauge calculations are inaccurate. Here we…
The order of high harmonics emitted by an atom in an intense laser field is limited by the so-called cutoff frequency. Solving the time-dependent Schr\"odinger equation, we show that this frequency can be increased considerably by a…
We use extreme-ultraviolet interferometry to measure the phase of high-order harmonic generation from transiently aligned CO2 molecules. We unambiguously observe a reversal in phase of the high order harmonic emission for higher harmonic…
We perform a detailed analysis of high-order harmonic generation (HHG) in atoms within the strong field approximation (SFA) by considering spatially inhomogeneous monochromatic laser fields. We investigate how the individual pairs of…