Coherent VUV and XUV Radiation Tunable to 90 nm, and Spectra of Rare Gas Dimers

Abstract

Progress in the development of coherent, tunable sources for the VUV and XUV has reached a stage where these sources will soon be found in most spectroscopic laboratories. The principal methods used in generating such radiation are frequency tripling and 4-wave sum-mixing (4-WSM) in rare gases and metal vapors [1, 2]. Recently, several novel schemes have been described which overcome the lack of transmitting window materials at λ < 104 nm. For example, rare gases as well as molecular gases have been pulsed through supersonic jets [3,4], a laminar flow of H2 has been used with a curtain of Ne buffer gas [5], and a rotating pinhole has been synchronized with pulses of the primary laser [6], all providing optical transmission during XUV generation with minimum gas flow. By these various means, it has been possible to produce XUV radiation which is tunable over limited regions, to wavelengths as short as 50 nm [7].