Graphene-containing plasma: a medium for the coherent extreme ultraviolet light generation.

We demonstrate the high-order harmonic generation of femtosecond pulses in the laser ablation plume containing the graphene nanoparticles. The harmonics up to the 33rd order were observed. The presence of graphene nanoparticles in the laser plasma was confirmed during the analysis of ablation debris. The comparative studies of harmonic generation from the ablation of graphene, carbon nanotubes, and diamond nanoparticles showed the advanced properties of the latter medium. [ABSTRACT FROM AUTHOR]