SATURATION OF 3RD-HARMONIC GENERATION IN A PLASMA OF SELF-INDUCED OPTICAL-BREAKDOWN DUE TO THE SELF-ACTION OF 80-FS LIGHT-PULSES

Generation of the second and third harmonics of 80-fs 1-mJ pulses from a Ti:sapphire laser in the plasma of self-induced optical breakdown i n atmospheric air is studied. Spatial self-action of fundamental radia tion accompanied by the broadening of spectra of fundamental radiation and optical harmonics is revealed. The self-action of light leads to the saturation of the efficiency of third-harmonic generation as a fun ction of the energy of fundamental radiation. An efficiency of third-h armonic generation up to 1.7x10(-3) is achieved with 1-kHz laser pulse s.