High photon flux XUV source driven by high repetition rate > 100 kHz fiber laser

Abstract

We report on the advantage of Yb-lasers at high repetition rate (>100kHz) to drive a XUV source based on high harmonic generation (HHG). The XUV source is based on a tight focusing configuration with high atomic density at the gas jet target. The XUV beamline has been optimized to be driven in three modalities. (1) directly with the output of an industrial Yb-laser with 350 fs pulse duration, (2) after post-compression down to 30 fs and (3) with the Yb-laser and post-compression to few cycle. We discuss how different XUV parameters can be optimized with each laser configuration. We study the improvement of the spectral width of harmonic lines respect to the pulse duration, useful for spectroscopy experiments. We present the increase of the cutoff photon energy with short pulses. We achieved up to 150 eV with a photon flux of up to 1.4×1012 photons/s/eV by using few cycle post-compressed pulses (14 fs).