Abstract Atomically thin Bi2O2Se has emerged as a novel two-dimensional (2D) material
with an ultrabroadband nonlinear optical response, high carrier mobility and excellent air …

Saturable absorber is a key component in ultrafast pulsed laser systems, which are pivotal in
ultrafast physics, high‐speed communication, etc. 2D materials appear to be superior …

Attosecond delay lines are key to enable time-resolved measurements on atoms, molecules,
plasma and solid-state materials. This tutorial review presents the current status of a wide …

Abstract Two-dimensional (2D) heterostructure provides a promising opportunity to create
new hybrid materials with unique tailored properties for novel electronic and photonic …

Laser state active controlling is challenging under the influence of inherent loss and other
nonlinear effects in ultrafast systems. Seeking an extension of degree of freedom in optical …

The free-electron laser in Hamburg, FLASH, is the first extreme ultra-violet and soft X-ray
free-electron laser (FEL) user facility and has been continuously upgraded since its start in …

Double core-holes (DCHs) show remarkable and sensitive effects for understanding
electron correlations and coherence. With advanced modulation of x-ray free-electron laser …

We generate high-order harmonics in a gaseous medium with tunable photon energy using
time-domain interferometry of double pulses in a noncollinear generation geometry. The …

A split-and-delay unit for the extreme ultraviolet and soft X-ray spectral regions has been
built which enables time-resolved experiments at beamlines FL23 and FL24 at the Free …

The coherent excitation and manipulation of a two-level system with ultrashort intense
extreme-ultraviolet laser fields is investigated theoretically, based on numerically solving the …