Description
XUV sources based on High-order Harmonic Generation (HHG) are versatile tools with attosecond capabilities. However, a significant drawback of the generation process remains the low conversion efficiency and the technical challenges associated with upscaling using high-power lasers. In high-intensity pump-probe experiments, it is therefore crucial to compensate for the low conversion efficiency by ensuring optimal photon delivery and focus quality at the application target. This requires minimizing aberrations while preserving short pulses, down to the attosecond regime.
Until now, many nonlinear XUV experiments have been limited to large-scale facilities, such as synchrotrons or free-electron lasers, where sufficient photon flux is available. Here, we present our approach to enable nonlinear studies using HHG-based sources. Recent advances in the L1-Allegra driving laser system (>40 mJ, 1 kHz, 15 fs, 830 nm), temporally synchronized with the FSYNC laser system (10 mJ, 1 kHz, 15fs, 830 nm), allow for a significant increase of XUV yield, opening the way for nonlinear and XUV-XUV pump-probe experiments with independent tuning of both beams.
We focus not only on scaling the HHG source but also on tailoring the spatio-temporal aspects of the XUV beam using single- and double-color driving beams for specific applications. Furthermore, we address the optimization of the whole chain of XUV beam delivery towards the sample, including passive and active stabilization and online monitoring. These improvements enable long-duration scans while maintaining the versatility of the HHG Beamline as a universal station for a wide range of user experiments.
