High-harmonic generation in lanthanide-containing plasmas

High-order harmonic generation (HHG) in atoms and molecules allows the study of the static and dynamic properties of these systems. We present the results of HHG studies in the plasmas produced using femtosecond and picosecond laser pulses on the surfaces of lanthanides and their oxides (La, Yb, Pr6O11, and Tb4O7). The plasmas induced by femtosecond pulses have proven to be a more efficient medium for HHG than the plasmas produced by picosecond pulses in the case of two-color pump HHG. We analyze the advantages of laser ablation using femtosecond pulses for the extension of the cutoff energy of generated harmonic in lanthanide plasma. We have shown that Yb plasma is the efficient medium for the harmonic generation up to the 73rd order, which is one of the largest orders generated in laser-produced plasmas.