Generation of tunable short pulse VUV radiation by four-wave mixing in xenon with femtosecond KrF-excimer laser pulses

A four-wave difference-frequency mixing scheme based on near resonant two-photon excitation of xenon with a femtosecond KrF excimer laser system is used to generate tunable short pulse radiation in the VUV and UV spectral range between 133 and 355 nm with output energies of several microjoules. Tunable nanosecond laser radiation in the range from 1905 nm to 185 nm is used. At excimer laser wavelengths of 193 nm (ArF), 308 nm (XeCl) and 350 nm (XeF), the process has been used to generate high power short pulse radiation by double-pass amplification in an additional excimer laser discharge. Output energies of 1.9, 3.0, and 2.8 mJ, respectively, have been obtained so far at pulse durations in the range of 1 ps. Nonlinear susceptibilities for the difference-frequency mixing process are calculated using a stationary susceptibility formalism and compared to experimental values