Tunable VUV light generation for the low-level resonant ionization detection of krypton

High-power tunable VUV light pulses with energies up to 0.7 micro J were generated in the 115.7-116.9-nm region by use of a two-photon resonant four-wave mixing scheme in a Xe-Ar gas mixture. This is the highest reported pulse energy that has been produced in this wavelength region using a four-wave mixing process. Efficient detection of krypton isotopes at densities as low as 10 atoms/cu cm was demonstrated by resonantly ionizing the atom through its one-photon allowed state at the vacuum wavelength of 116.49 nm.