Frequency conversion of ultraviolet short-pulse laser radiation

Summary form only given. The generation of intense laser radiation in the vacuum and extreme ultraviolet spectral range is still a challenging problem. Starting from a titanium sapphire laser, conversion efficiencies up to 4/spl times/10/sup -5/ in the 15th harmonic (53 nm) have been demonstrated in the plateau region. Compared to these high-order processes one can enter into this spectral range with low-order processes starting from KrF laser radiation. The conversion into the 3rd and 5th harmonic can yield a much higher efficiency. Different approaches for the generation of coherent VUV and XUV radiation with a 10 mJ 400 fs KrF excimer-laser system are studied. In experiments it has been shown that four-wave difference-frequency mixing in Xe, using a near two-photon resonance with the KrF laser radiation, is well suited for the generation, of tunable VUV radiation in the range of 130-200 nm.