Enhanced production of tunable VUV radiation by phase-matched frequency tripling in krypton and xenon

Abstract

Nonresonant frequency tripling of intense dye laser radiation in negative dispersive Kr ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\lambda = 1203-1235</tex> Å ) is efficiently enhanced by phase matching with the positive dispersive tare gas Ar or Xe. Phase matching of Kr with Ar improved the efficiency of the conversion of 3648 Å to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L_{\alpha} = 1216</tex> Å by more than two orders of magnitude. At <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L_{\alpha}, 16</tex> W ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4 \cdot 10^{10}</tex> photons/pulse) could be generated with 1.5 MW pulses of a frequency doubled dye laser. The optimum conversion is limited by absorption of the VUV in the rare gas mixture and by dielectric breakdown. In mixtures of Kr and Xe, the dependence of the VUV on the density of the two gas components indicates a phase difference between their contributions to the induced third-order polarization. Measurements of the VUV output of different Kr-Xe mixtures provide a determination of the ratio of the third-order nonlinear susceptibilities χ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Kr</inf> /χ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Xe</inf> and of the wave vector mismatches per atom C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Kr</inf> /C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Xe</inf> at wavelengths <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\lambda = 1205-1230</tex> Å Besides frequency tripling in Kr, third-harmonic generation of blue dye laser light ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\lambda = 4208-4406</tex> Å) has been investigated in Xe phase matched with Kr. The peak power of the tunable VUV at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\lambda = 1403-1469</tex> Å exceeded 30 W ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8.7 \cdot 10^{10}</tex> photons/pulse).