title: Two-photon resonant upconversion in xenon.
abstract: Coherent radiation at various VUV wavelengths, e.g., 125.9, 126.1, and 125.4 nm, has been generated through fourwave mixing processes enhanced by two-photon resonances in xenon. Maximum efficiencies of the order of 10(-4) were achieved. Maximum output intensities of difference generation (2omega(1) - omega(2)) for 7p[0 (1/2)](0), 7p[1 (1/2)](2), and 6p' [1 (1/2)](2) resonant states occurred at xenon pressures of 24, 12.5, and 4 Torr, corresponding to values of phase mismatch per atom of 1.2 x 10(-18), 2.3 x 10(-18), and 7.1 x 10(-18) esu, respectively. Parametric generation at 117.0 nm through the 7s[1(1/2)](0)(1) state was also observed.
authors.forename: Y M
authors.initials: YM
authors.lastname: Yiu
authors.forename: K D
authors.initials: KD
authors.lastname: Bonin
authors.forename: T J
authors.initials: TJ
authors.lastname: McIlrath