The history and current status of the Keldysh theory of strong field ionization are reviewed.
The focus is on the fundamentals of the theory, its most important applications and those …

Free-electron lasers produce extremely brief, coherent, and bright laser-like photon pulses
that allow to image matter at atomic resolution and at timescales faster than the …

Strong-field physics is currently experiencing a shift towards the use of mid-IR driving
wavelengths. This is because they permit conducting experiments unambiguously in the …

Sustainable hydrogen, produced from renewable sources such as solar or wind, plays a
decisive role in driving industrial decarbonization. Among hydrogen production …

X-ray free-electron lasers provide unique opportunities for exploring ultrafast dynamics and
for imaging the structures of complex systems. Understanding the response of individual …

Photoelectron holography constitutes a powerful tool for the ultrafast imaging of matter, as it
combines high electron currents with subfemtosecond resolution, and gives information …

We consider selectivity of strong-field ionization in circularly polarized laser fields to the
sense of electron rotation in the laser polarization plane in the initial state. We show that, in …

The distant projection of high-peak and average-power laser beams in the atmosphere is a
long-standing goal with a wide range of applications. Our early proof-of-principle …

We demonstrate a new highly tunable technique for generating meter-scale low density
plasma waveguides. Such guides can enable laser-driven electron acceleration to tens of …

Strong terahertz (THz) electric and magnetic transients open up new horizons in science
and applications. We review the most promising way of achieving sub-cycle THz pulses with …