相关论文: Site-selective-induced isomerization of formamide
In recent years, ultrafast pump-probe spectroscopy has provided insightful information about nonequilibrium dynamics of excitations in materials. In a typical experiment of time-resolved x-ray absorption spectroscopy, the systems are…
The new regime of resonant nuclear photoexcitation rendered possible by x-ray free electron laser beams interacting with solid state targets is investigated theoretically. Our results unexpectedly show that secondary processes coupling…
X-ray free-electron lasers are sources of coherent, high-intensity X-rays with numerous applications in ultra-fast measurements and dynamic structural imaging. Due to the stochastic nature of the self-amplified spontaneous emission process…
We present the experimental demonstration of a method for generating two spectrally and temporally separated pulses by an externally seeded, single-pass free-electron laser operating in the extreme-ultraviolet spectral range. Our results,…
The extremely high power densities and short durations of single pulses of x-ray free electron lasers (XFELs) have opened new opportunities in atomic physics, where complex excitation-relaxation chains allow for high ionization states in…
Recently developed circularly polarized X-ray light sources can probe ultrafast chiral electronic and nuclear dynamics through spatially localized resonant core transitions. We present simulations of time-resolved circular dichroism (TRCD)…
X-ray free-electron lasers (FEL) deliver ultrabright X-ray pulses, but not the sequences of phase-coherent pulses required for time-domain interferometry and control of quantum states. For conventional split-and-delay schemes to produce…
We report experiments on field-free molecular alignment performed at FLASH, the free electron laser (FEL) in Hamburg. The impulsive alignment induced by a 100 fs near-infrared laser pulse in a rotationally cold CO_2 sample is characterized…
The capability of generating two intense, femtosecond x-ray pulses with controlled time delay opens the possibility of performing time-resolved experiments for x-ray induced phenomena. We have applied this capability to study the…
Femtosecond high-intensity laser pulses at intensities surpassing $10^{14} \,\text{W}/\text{cm}^2$ can generate a diverse range of functional surface nanostructures. Achieving precise control over the production of these functional…
Impulsive orientation of symmetric-top molecules excited by two-color femtosecond pulses is considered. In addition to the well-known transient orientation appearing immediately after the pulse and then reemerging periodically due to…
The ingenious idea of single molecule imaging by hard x-ray Free Electron Laser (X-FEL) pulses was recently proposed by Neutze et al. [Nature,406,752(2000)]. However, in their numerical modelling of the Coulomb explosion several…
The development of X-ray free-electron lasers (XFELs) has enabled ultrafast X-ray diffraction (XRD) experiments, which are capable of resolving electronic/vibrational transitions and structural changes in molecules, or capturing molecular…
Ultrafast imaging is essential in physics and chemistry to investigate the femtosecond dynamics of nonuniform samples or of phenomena with strong spatial variations. It relies on observing the phenomena induced by an ultrashort laser pump…
Recent experimental and theoretical investigations on asymmetric field emission induced by weak femtosecond laser pulses and also its emission mechanisms are briefly reviewed. The emission mechanisms are discussed further for a wider range…
A pump-probe dark-field X-ray microscopy (DFXM) experiment was carried out at the Advanced Photon Source (APS) with nanosecond drive laser pulses and hybrid mode X-ray probe pulses. We observe a thermal decay due to laser-induced heat…
We demonstrate the possibility to run a single-pass free-electron laser in a new dynamical regime, which can be exploited to perform two-colour pump-probe experiments in the VUV/X-ray domain, using the free-electron laser emission both as a…
Understanding the complex plasma dynamics in ultra-intense relativistic laser-solid interactions is of fundamental importance to the applications of laser plasma-based particle accelerators, creation of high energy-density matter,…
Time-resolved X-ray scattering patterns from photoexcited molecules in solution are in many cases anisotropic at the ultrafast time scales accessible at X-ray Free Electron Lasers (XFELs). This anisotropy arises from the interaction of a…
We propose a method for a straightforward characterization of the temporal shape of femtosecond pulses in the extreme-ultraviolet/soft X-ray spectral region. The approach is based on the presence of a significant linear frequency chirp in…