A very convenient setup to generate intense VUV coherent light at 125 nm with use of nonlinear effects in mercury vapor at room temperature

Using only one dye laser, efficient generation of VUV radiation (10/sup 13/ photons/pulse) is demonstrated at 125.140 nn and 125.053 nm by four-wave sum-frequency mixing in a room-temperature mercury vapor. The emission at 125.053 mn, which is out of two-photon resonance, but near three-photon resonance, has been observed for the first time and is carefully analyzed. In particular, numerical calculations have been carried out for Gaussian pump beams, taking into account absorption of VUV photons and optical Kerr effect. The results of the calculations reproduce the VUV emission lineshape and power saturation effects measured in the experiment.<
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