Development of a high-flux XUV source based on high-order harmonic generation

An experimental study of the scaling laws for optimal driving conditions and output properties of the beam generated through high-order harmonic generation on the f-number of laser focusing is presented. Alteration of experimental parameters for focal lengths from 0.3 to 5 m, in optimal conditions for phase-matching (in terms of driving laser intensity, gas cell length and gas pressure) was carried out, enabling the experimental verification of the scaling laws for output parameters, such as XUV pulse energy, conversion efficiency and divergence of the harmonic beam. In order to improve the yield of the harmonic signal, allowing the source to become convenient for applications that require pulses with high photon numbers, a loose focusing geometry with high peak-power driver pulses was implemented. A high harmonic beam with energy up to 40 nJ per pulse was generated in Ar with a focal length of 5 m. Application of the scaling laws verified within this study allows the estimation of parameters for a future high harmonic source that is being implemented at ELI Beamlines facility.