Nonlinear-optical processes in the near-resonant two-photon excitation of xenon by femtosecond KrF-excimer-laser pulses

摘要

The nonlinear response of xenon gas due to a near-resonant two-photon excitation at the 5p6 1S0→6p[1/2]0 transition with a femtosecond KrF-excimer-laser system is investigated for the intensity range 1010–1015 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 ‖χ(3)‖=10-48 to 10-50 m5/V2 have been determined, which are in good agreement with calculations.