Navigation und Service

High harmonic generation

In high-harmonic generation (HHG), an intense, ultrafast laser pulse is tightly focused into a volume of gas atoms. The extremely nonlinear interaction generates new frequencies at odd harmonics of the driving laser frequency. These harmonics can extend over a wide photon energy range of 10–2000 eV and retain the polarization/coherence properties of the driving laser.

This offers a unique opportunity to extend the temporal and spatial resolution to unprecedented fs and nm scales respectively in the same experiment. Access to HHG radiation recently allowed a number of proof-of-principle solid-state and surface physics experiments demonstrating the strength of this approach and bringing new insights to a range of cutting edge scientific questions, including:

  • identification of the laser-assisted surface photoelectric effect
  • first attosecond spectroscopy experiment in a condensed matter system
  • HHG generated XUV pulses for testing thermal transport from nanoscale hotspots
  • ultrafast molecular, plasma and materials dynamics
  • first element-specific lab-based magnetization dynamics studies with femtosecond temporal resolution