A compact, turnkey, narrow-bandwidth, tunable, and high-photon-flux extreme ultraviolet source

We report on a compact high-photon-flux extreme ultraviolet (XUV) source based on high harmonic generation. A high XUV-photon flux (>10(13) photons/s) is achieved at 21.8 eV and 26.6 eV. The narrow spectral bandwidth (Delta E/E < 10(-3)) of the generated harmonics is in the range of state-of-the-art synchrotron beamlines and enables high resolution spectroscopy experiments. The robust design based on a fiber-laser system enables turnkey-controlled and even remotely controlled operation outside specialized laser laboratories, which opens the way for a variety of applications.