Infrared to ultraviolet light conversion in laser-cluster interactions.

Spectrum conversion phenomena accompanying ionization of atomic clusters by few-cycle laser pulses are studied with the free (natural) plasma oscillations taken into account. These oscillations are found to be excited at the pulse leading front and to persist after passage of the pulse through the cluster, thus increasing the energy deposition to the plasma and affecting dramatically the scattered radiation spectrum: the Xe cluster irradiated by the near-infrared (800 nm) single-cycle pulse reradiates as a source of the ultraviolet light (360 nm).