Continuously tunable high photon flux high harmonic source
Alexander Kirsche, Martin Gebhardt, Robert Klas, Lucas Eisenbach, Wilhelm Eschen, Joachim Buldt, Henning Stark, Jan Rothhardt, Jens Limpert
Abstract
ph/s/eV spanning from 50 eV to 70 eV is presented. The setup consists of a high-power fiber laser with a subsequent multipass cell followed by a waveguide-based high harmonic generation setup. Spectral tuning over the full line spacing is achieved by slightly adjusting the lasers driving pulse energy, utilizing nonlinear propagation effects and pulse chirping. The presented method enables a high tuning speed while delivering reproducible and reliable results due to a simple experimental realization. For possible future experiments, a method for continuous, on-demand pulse-to-pulse switching of the generated XUV radiation with full spectral coverage is conceived.