NONLINEAR-OPTICAL PROCESSES IN THE NEAR-RESONANT 2-PHOTON EXCITATION OF XENON BY FEMTOSECOND KRF-EXCIMER-LASER PULSES

The nonlinear response of xenon gas due to a near-resonant two-photon excitation at the 5p6 S-1(0)-->6p[1/2]0 transition with a femtosecond KrF-excimer-laser system is investigated for the intensity range 10(10)-10(15) W/cm2. Stimulated hyper-Raman scattering and amplified spontaneous emission of atomic xenon are observed at wavelengths around 823 and 828 nm. These emissions are superimposed by four-wave parametric-oscillation processes leading to strong ultrashort continuum radiation in the visible and near-infrared (650-850 nm), uv (185-400 nm), and vacuum ultraviolet (147-155 nm) spectral ranges with output powers up to 100 MW. From difference-frequency-mixing experiments microscopic nonlinear susceptibilities in the range of \chi(3)\ = 10(-48) to 10(-50) m5/V2 have been determined, which are in good agreement with calculations.