Related papers: XUV fluorescence as a probe of laser-induced heliu…
Using ab-initio non-Born-Oppenheimer simulations, we demonstrate amplification of XUV radiation in a high-harmonic generation type process using the example of the hydrogen molecular ion. A small fraction of the molecules is pumped to a…
Superfluid He nanodroplets resonantly excited by extreme ultraviolet (XUV) pulses exhibit complex relaxation dynamics, including the formation of metastable excited He$^*$ atoms trapped in bubbles, the desorption of excited atoms from the…
High-intensity extreme ultraviolet (XUV) pulses from a free-electron laser can be used to create a nanoplasma in clusters. In Ref. [Michiels et al. PCCP, 2020; 22: 7828-7834] we investigated the formation of excited states in an XUV-induced…
We study the dynamics of avalanche ionization of pure helium nanodroplets activated by a weak extreme-ultraviolet (XUV) pulse and driven by an intense near-infrared (NIR) pulse. In addition to a transient enhancement of ignition of a…
Photoelectron emission from excited states of laser-dressed atomic helium is analyzed with respect to laser intensity-dependent excitation energy shifts and angular distributions. In the two-color XUV (exteme ultra\-violet) -- IR (infrared)…
The interaction of intense extreme ultraviolet (XUV) laser pulses ($\lambda=32\rm\,nm$, $I=10^{11-14}$\,W/cm$^2$) with small rare-gas clusters (Ar$_{147}$) is studied by quasi-classical molecular dynamics simulations. Our analysis supports…
Coherent diffractive imaging of individual free nanoparticles has opened novel routes for the in-situ analysis of their transient structural, optical, and electronic properties. So far, single-shot single-particle diffraction was assumed to…
High intensity XUV radiation from a free-electron (FEL) was used to create a nanoplasma inside ammonia clusters with the intent of studying the resulting electron-ion interactions and their interplay with plasma evolution. In a plasma-like…
Pulses of extreme ultraviolet (XUV) light, with wavelengths between 10 and 100$\,$nm, can be used to image and excite ultra-fast phenomena such as the motion of atomic electrons. Here we show that the illumination of plasma with…
The effective transparency of rare-gas clusters, post-interaction with an extreme ultraviolet (XUV) pump pulse, is predicted by using an atomistic hybrid quantum-classical molecular dynamics model. We find there is an intensity range for…
The relaxation of photoexcited nanosystems is a fundamental process of light-matter interaction. Depending on the couplings of the internal degrees of freedom, relaxation can be ultrafast, converting electronic energy in a few fs, or slow,…
The development of compact and bright XUV and soft X-ray sources based on high-order harmonic generation is boosting advances towards understanding the behavior of matter with extreme temporal and spatial resolutions. Here, we report…
Extreme ultraviolet (XUV) light sources allow for the probing of bound electron dynamics on attosecond scales, interrogation of high-energy-density matter, and access to novel regimes of strong-field quantum electrodynamics. Despite the…
Semi-classical molecular dynamics simulations of small rare gas clusters in short laser pulses of 100 nm wavelength were performed. For comparison, the cluster response to 800 nm laser pulses was investigated as well. The inner ionization…
We study theoretically the photoabsorption spectra of an attosecond XUV pulse by a laserdressed atomic system. A weak XUV excites an autoionizing state which is strongly coupled to another autoionizing state by a laser. The theory was…
We report on a compact and spectrally intense extreme-ultraviolet (XUV) source, which is based on high-harmonic generation (HHG) driven by 395 nm pulses. In order to minimize the XUV virtual source size and to maximize the XUV flux, HHG is…
We present a theoretical study of transient absorption and reshaping of extreme ultraviolet (XUV) pulses by helium atoms dressed with a moderately strong infrared (IR) laser field. We formulate the atomic response using both the…
In this study the generation of energetic coherent extreme ultraviolet (XUV) radiation with controlled polarization, is reported. The XUV radiation results from the process of high harmonic generation (HHG), in a gas phase atomic medium,…
Studies of ultrafast dynamics along with femtosecond-pulse metrology rely on non-linear processes, induced solely by the exciting/probing pulses or the pulses to be characterized. Extension of these approaches to the extreme-ultraviolet…
The ionization dynamics of helium droplets in a wide size range from 220 to 10^6 He atoms irradiated with intense femtosecond extreme ultraviolet (XUV) pulses of 10^9 {\div} 10^{12} W/cm2 power density is investigated in detail by…