We review the phenonomena which occur in multiphoton physics when the electric field of
the applied laser radiation becomes comparable with the Coulomb field strength seen by an …

We discuss, via a numerical calculation, the main properties of atomic photoelectron spectra,
as they would be obtained by using a radiation pulse containing N+ 1 frequencies …

We study high-order harmonic generation at a high pumping energy using a long focal
length lens. We identify different saturation regimes of the harmonic emission, revealing the …

We present two methods for measuring the duration of ultrashort high-harmonic pulses
produced by an intense laser pulse propagating in an atomic gas. Both methods rely on the …

With a phase-modulated extreme ultraviolet pulsed laser source the frequency of the 1 1 S-2
1 P transition of helium at 58 nm has been measured. The phase modulation scheme …

When the radiation pulse of an intense laser propagates in gas, the atoms of the gas emit
odd harmonics of incident radiation. If λ is the incident wavelength, the outgoing radiation …

Coherent extreme-ultraviolet emission can be obtained through high-harmonic generation
and multiphoton excitation from atoms exposed to a strong laser field. We report the …

We demonstrate that frequency-domain interferometry can be performed in the extreme
ultraviolet range using high-order harmonics. We first show that two phase-locked harmonic …

We have investigated how high-order harmonics generated in rare gases depend on the
atomic density. The peak and the profile of the atomic density in the interaction region were …

Numerical simulations of high-order harmonic generation in the molecular ions H 2+ and H
3 2+ show that two-color intense (I≃ 10 14 W/cm 2) short (< 1− psec) laser pulse excitation …