Improved efficiency of materials processing by dual action of XUV/Vis-NIR ultrashort laser pulses and comprehensive study of high-order harmonic source at PALS

摘要

We demonstrate a novel experimental method for improvement of efficiency of structural surface modification of various solids (PMMA, amorphous carbon) achieved by simultaneous action of XUV (21.6 nm), obtained from high-order harmonic generation (HHG), and VIS-NIR (410/820 nm) laser pulses. Although the fluence of each individual pulse was far below the surface ablation threshold, very efficient and specific material modification was observed after irradiation by a single or a few shots of mixed XUV/VIS-NIR radiation.rnWe also report results on comprehensive characterization of ultrafast coherent X-ray beamline at Prague Asterix Laser System (PALS). The beamline is based on 1 kHz, table-top, high-order harmonic generation source capable to deliver fully coherent beam in the 30 nm spectral range. Ti:sapphire (810 nm, 1 kHz) laser pulses with a duration of 35 fs and energy 1.2 mJ have been focused into gas cell containing conversion medium (Ar). To achieve highly efficient HHG we will apply the technique of guided laser pulses. Source parameters were investigated.