Related papers: Phase-matched coherent hard x-rays from relativist…
The interaction of intense mid-infrared laser fields with atoms and molecules leads to a range of new opportunities, from the production of bright, coherent radiation in the soft x-ray range to imaging molecular structures and dynamics with…
High-harmonic generation (HHG) in the two topological phases of a finite, one-dimensional, periodic structure is investigated using a self-consistent time-dependent density functional theory (TDDFT) approach. For harmonic photon energies…
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…
Effects of the laser pulse wavelength and intensity on the HHG production from the \textit{ionic} and \textit{homolytic} pre-ionization transient states of the two-electron H$_{2}$ system exposed to ultrashort intense laser pulses are…
High harmonic generation (HHG) from gas phase atoms (or molecules) has opened up a new frontier in ultrafast optics, where attosecond time resolution and Angstrom spatial resolution are accessible. The fundamental physical pictures of HHG…
We report evidence for the first generation of XUV spectra from relativistic surface high-harmonic generation (SHHG) on plasma mirrors at a kilohertz repetition rate, emitted simultaneously with energetic electrons. SHHG spectra and…
We demonstrate that phase-matched frequency upconversion of ultrafast laser light can be extended to shorter wavelengths by using longer driving laser wavelengths. Experimentally, we show that the phase-matching cutoff for harmonic…
High-harmonic generation is typically thought of as a sub-laser-cycle process, with the electron's excursion in the continuum lasting a fraction of the optical cycle. However, it was recently suggested that long-lived Rydberg states can…
We report theoretical calculations of high harmonic generation (HHG) by intense infrared lasers in atomic and molecular targets taking into account the macroscopic propagation of both fundamental and harmonic fields. On the examples of Ar…
With the generation of high order harmonics (HHG) on the plasma surface it is possible to turn the laser pulse into a train of attosecond or even zeptosecond pulses in the back radiation. These attosecond pulses may have amplitude several…
Recent advancements in ultrafast laser systems and high harmonic generation (HHG) techniques have enabled time-resolved photoemission spectroscopy on femtosecond timescales, opening up unprecedented opportunities to explore quantum…
High harmonic generation (HHG) is a highly nonlinear emission process in which systems driven by intense laser pulses emit integer multiples (harmonics) of the driving field. This feature is considered universal to all occurrences of HHG.…
A scheme for quasi-phase-matching high-harmonic generation is proposed in which polarization beating within a hollow core birefringent waveguide modulates the generation of harmonics. The evolution of the polarization of a laser pulse…
The growing requirements of pump-probe techniques and nonlinear optics experiments greatly promote the studies of two-color free-electron lasers (FELs). We propose a new method to generate coherent two-color pulses in a high-gain harmonic…
We experimentally observe longer than long trajectory influence in high order harmonic generation (HHG) by varying the peak intensity of the driving laser field through either direct attenuation, or by chirping the laser pulse. Using 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 experimentally disentangle the contributions of different quantum paths in high-order harmonic generation (HHG) from the spectrally and spatially resolved harmonic spectra. By adjusting the laser intensity and focusing position, we…
We consider harmonics generation and wave-mixing by two-color multi photon resonant excitation of three-level atoms/molecules in strong laser fields. The coherent part of the spectra corresponding to multicolor harmonics generation is…
The cut-off regime of high-order harmonic generation (HHG) by atoms in an intense laser field is studied numerically and analytically. We find that the cut-off regime is characterized by equal dephasing between the successive harmonics. The…
High harmonic generation (HHG) is an extreme nonlinear process where intense pulses of light drive matter to emit high harmonics of the driving frequency, reaching the extreme ultraviolet (XUV) and x-ray spectral ranges. So far, the HHG…