Controlled acceleration of GeV electron beams in an all-optical plasma waveguide.

Laser-plasma accelerators (LPAs) produce electric fields of the order of 100 GV m, more than 1000 times larger than those produced by radio-frequency accelerators. These uniquely strong fields make LPAs a promising path to generate electron beams beyond the TeV, an important goal in high-energy physics. Yet, large electric fields are of little benefit if they are not maintained over a long distance.

Survey of spatio-temporal couplings throughout high-power ultrashort lasers.

The investigation of spatio-temporal couplings (STCs) of broadband light beams is becoming a key topic for the optimization as well as applications of ultrashort laser systems. This calls for accurate measurements of STCs. Yet, it is only recently that such complete spatio-temporal or spatio-spectral characterization has become possible, and it has so far mostly been implemented at the output of the laser systems, where experiments take place.

Table-top extreme ultraviolet second harmonic generation.

The lack of available table-top extreme ultraviolet (XUV) sources with high enough fluxes and coherence properties has limited the availability of nonlinear XUV and x-ray spectroscopies to free-electron lasers (FELs). Here, we demonstrate second harmonic generation (SHG) on a table-top XUV source by observing SHG near the Ti M edge with a high-harmonic seeded soft x-ray laser. Furthermore, this experiment represents the first SHG experiment in the XUV.

Nonlinear ionization dynamics of hot dense plasma observed in a laser-plasma amplifier.

Understanding the behaviour of matter under conditions of extreme temperature, pressure, density and electromagnetic fields has profound effects on our understanding of cosmologic objects and the formation of the universe. Lacking direct access to such objects, our interpretation of observed data mainly relies on theoretical models. However, such models, which need to encompass nuclear physics, atomic physics and plasma physics over a huge dynamic range in the dimensions of energy and time, can only provide reliable information if we can benchmark them to experiments under well-defined laboratory conditions.

Monitoring shot-to-shot variations of soft x-ray sources using aluminum foils.

We report a straightforward beam splitter in the soft x-ray spectral range using a thin oxidized aluminum foil. As it allows us to monitor reliably shot-to-shot variations in energy and in energy distribution, this beam splitter is of high interest for the simultaneous use of diagnostics for soft x-rays sources. We measure a transmission of 0.