palm_1998

H. Palm and F. Merkt, “Generation of tunable coherent extreme ultraviolet radiation beyond 19 eV by resonant four-wave mixing in argon”, Appl. Phys. Lett. 73, 157 (1998)

Source record · Catalogue · Review register

DOI: 10.1063/1.121741

Source kind: measurement

Recorded technique: Two-photon-resonant sum-frequency four-wave mixing nu_XUV = 2 nu_1 + nu_2 in a pulsed argon jet (2-5 bar stagnation), nu_1 on the Ar 3p5 4p[5/2]2 <- 3p6 two-photon resonance at 189.3 nm (the sum of a frequency-doubled dye laser at 230.4 nm and the 1064.55 nm Nd:YAG fundamental in BBO), nu_2 a frequency-doubled dye laser (205-770 nm range of the setup); the XUV separated by a monochromator and measured with a calibrated solar-blind photomultiplier. Demonstrated by a PFI-ZEKE photoelectron spectrum of O2 b 4Sigma_g- (v+ = 1) near 18.3 eV.

Materials in structured entries: None recorded.

Dataset quantities: None recorded.

Contents: 0 datasets; 0 formulas.

Curation notes

Appl. Phys. Lett. 73(2), 157-159 (13 July 1998) = PDF pages 2-4 (PDF page 1 is the publisher’s cover). Identity checked against PDF page 2 (journal, volume, number, date, pages, title, authors).

NOTHING TAKEN. The paper reports XUV output (photons per pulse, a conversion efficiency of about 10^-6, a bandwidth of 0.1 cm^-1) and relative signals, not a property of argon in the vocabulary: (1) The Ar 3p5 4p[5/2]2 two-photon resonance, ‘2 nu = 105 617.3 cm^-1 (Ref. 4)’ (p. 157; the abstract’s ‘105 617 cm^-1’), is Moore’s 1949 table, reproduced (rupper_2004, TC-900, quotes Minnhagen’s 105 617.2700 = NIST’s, and measured 105 617.54(60)). The other resonances named (Ar 4p[1/2]0 at 186.8 nm and 4p’[1/2]0 at 184.0 nm; Kr 5p[1/2]0 212.5 nm, 5p’[1/2]0 202.3 nm (98 856 cm^-1), 6p[1/2]0 192.7 nm) are positions only, and agree with NIST’s levels as vacuum wavelengths (2 / 107 054.27, 108 722.62, 94 092.86, 98 855.07 and 103 761.63 cm^-1 = 186.82, 183.96, 212.56, 202.32 and 192.75 nm; computed 2026-10-09). (2) ‘Switching to the krypton 192.7 nm resonance under identical experimental conditions, a 45 times stronger XUV signal was found’ (p. 159), and the Kr 5p[5/2]2 resonance is ‘typically, a factor of 100 weaker’ than the Kr J = 0 resonances: four-wave-mixing outputs, not two-photon cross sections or transition strengths. (3) The XUV energies are consistent with the resonance: 105 617.3 + 1e7/237.5 nm = 147 722.6 cm^-1 = 18.315 eV (printed 18.32), + 1e7/219 nm = 18.756 (18.76), the third harmonic of nu_1, 3 x 52 808.65 cm^-1 = 19.642 eV (19.64), and nu_2 at the 189 nm BBO limit gives 19.655 eV (‘up to 19.66’). Not reproduced: the krypton resonance’s limit ‘beyond 155 700 cm^-1 (19.3 eV)’ (p. 157); with the same 189 nm limit it would be 103 761.6 + 52 910 = 156 672 cm^-1 (19.42 eV).

COMPARISON with rupper_2004 (TC-900), the same group’s later source: it uses all five Ar 3p5 4p two-photon resonances, reached with one F2-laser photon (157.63 nm) and one tripled-dye photon instead of two photons at 189.3 nm, and its Table I gives relative four-wave-mixing efficiencies 1.2(2) for 4p[5/2]2, 4.0(12) for 4p[1/2]0 and 7.5(24) for 4p’[1/2]0 (4p[3/2]2 = 1): the J = 0 resonances this paper expected to ‘improve the conversion efficiencies at the highest energies’ (p. 159) are 3.3 and 6.3 times the 4p[5/2]2 resonance used here, which is consistent with, though much smaller than, the factor of about 100 between krypton’s J = 2 and J = 0 resonances quoted here. Neither paper gives a two-photon cross section.

TEXT-LAYER NOTE. The PDF’s text layer (and the library’s paper.md) drops the mu of microjoule: the page prints laser 1’s energy at the vacuum apparatus as ‘10-20 uJ’ (p. 158, rendered page checked), the text layer ‘10-20 mJ’. Not used.

FURTHER TWO-PHOTON DATA CITED: none with values (Refs. 5-7, the Kr 202.3 nm resonance in four-wave mixing: H. H. Fielding, T. P. Softley and F. Merkt, Chem. Phys. 155, 257 (1991); J. W. Hepburn, Chem. Soc. Rev. 25, 281 (1996); F. Merkt et al., J. Phys. B 31, 1705 (1998); not in the library).

Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets

No datasets are recorded.

Formulas

No formulas are recorded.

Corrections

No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.