bischel_1979#
W. K. Bischel, J. Bokor, D. J. Kligler and C. K. Rhodes, “Nonlinear optical processes in atoms and molecules using rare-gas halide lasers”, IEEE J. Quantum Electron. QE-15, 380-392 (1979)
Source record · Catalogue · Review register
Source kind: theory
Recorded technique: A review of the authors’ experiments with ArF (193 nm) and KrF (248 nm) lasers (two-photon excitation of H2 E,F, Kr 4p5 6p and Xe 5p5 6p; Xe+ by two-photon ionisation; XeF*, XeO*, KrO*; OCS photolysis), with estimates of two-photon absorption coefficients from second-order perturbation theory (Sec. II, Eqs. 1-3, Table I): one intermediate state, transition moments mu_1^2 and mu_2^2 of order 1 debye^2, an energy denominator, and a Gaussian laser line of 100 cm^-1 for the bound transitions (Ref. 18’s (2 Delta^2 + Delta nu_D^2)^1/2 replacing the Doppler width).
Materials in structured entries: Xe
Dataset quantities: multiphoton_ionization_cross_section
Contents: 1 dataset; 0 formulas.
Curation notes#
Journal pp. 380-392 = PDF pages 1-13 (a scan with a text layer). Identity checked on the first page (IEEE Journal of Quantum Electronics, vol. QE-15, no. 5, May 1979, p. 380; W. K. Bischel, J. Bokor, D. J. Kligler and C. K. Rhodes; manuscript received November 1, 1978, revised January 16, 1979) on 2026-10-09.
THE DEFINITION (p. 381, Eq. 1; p. 382), quoted: ‘the two-photon absorption cross section for light at frequency nu_2 with intensity I_2 induced by light at frequency nu_1 with intensity I_1 is given by sigma(nu_2) = alpha I_1 = (2 pi)^3 / (h c^2) nu_2 |M_fg|^2 g(nu_1, nu_2) I_1’ (Eq. 1), and the rate equation (4) uses ‘W_fg = alpha I^2 / hbar omega’ (p. 382): alpha in cm^4/watt is the transition rate per atom times hbar omega / I^2, the definition mccown_1982 (its Eq. 9, TC-884) and hodges_1981 (its Eq. 1, which cites this paper) use. The generalised cross section on the photon flux is sigma_2 = alpha hbar omega (1.03e-52 cm4 s for alpha = 1e-34 at 193 nm; not printed). For the ionisation row the ‘Line Width’ entering g is not the laser’s: footnote (g), ‘~10^9 MHz’, ‘Estimated for photoionization continuum’ (about 3 x 10^4 cm^-1), against footnote (a)’s ‘Estimated laser linewidth’ of 3 x 10^6 MHz (100 cm^-1) for the bound rows. The paper prints the inputs but not Eq. (1)’s polarisation factors or units; the estimates are not reproduced here.
THE XENON ESTIMATE (Table I, p. 381): Xe, 193 nm, excited product Xe+, energy denominator 16 x 10^3 cm^-1, line width ~10^9 MHz (g), mu_1^2 = mu_2^2 = 1 debye^2, alpha = 1 x 10^-34 cm4/watt. The text (p. 386): at 193 nm ‘the two-photon linewidth covers the region from 103 300-103 560 cm^-1’, between the Xe+ 2P3/2 and 2P1/2 limits (Fig. 4), and ‘Because autoionizing states are observed in the linear ionization spectrum [40] in both the ns and nd channels, it is likely that similar np and nf channels will influence the two-photon amplitude. These resonances could enhance the value of alpha given in Table I by a factor of ~10^2.’ Repeated on p. 388: ‘sigma / I ~ 10^-34 cm4/W (see Table I)’; with ‘an Xe density ~3 x 10^17 cm^-3 and an optical intensity of 10^9 W/cm^2’ it gives ‘an estimated ion density of ~3 x 10^11 cm^-3’ (the laser pulse 20 ns): the definition above gives 5.8e11, twice the printed value (2.9e11 for a 10 ns pulse); an order-of-magnitude estimate. The authors observed Xe+ (828 nm recombination line, Xe2* emission at 172 nm, Fig. 5) but measured no coefficient: ‘an accurate measurement of the two-photon ionization cross section could make this an important alternate technique’ (p. 388).
QUOTED ELSEWHERE, CHECKED. mccown_1982 (TC-884) holds ‘1 x 10^-34’ as Bischel et al.’s (Table I there, Ref. 11): the value matches (the script checks it). FINDING: mccown_1982 describes it as an estimate ‘assuming a laser linewidth of 100 cm-1’ (its p. 3322, from this paper’s p. 381); this paper’s Table I gives the Xe+ row the continuum width of footnote (g), ~10^9 MHz, not the 100 cm-1 (3 x 10^6 MHz) of the bound rows. The factor ~10^2 for autoionising resonances that McCown et al. and hodges_1981 quote matches p. 386. hodges_1981 quotes ‘1 x 10^-34 cm4 W-1’: matches.
KRYPTON (OEP 6, Q2). The paper has no krypton two-photon ionisation cross section (table, vector figure or raster figure). Table I’s Kr row is a bound two-photon excitation estimate: 193 nm, Kr* 4p5 6p, energy denominator 30 x 10^3 cm^-1, 100 cm^-1 laser line (3 x 10^6 MHz), alpha = 1 x 10^-31 cm4/watt; the experiment (pp. 386-387) excites 4p5 6p(1 1/2)2 ‘at 103 363 cm^-1’ and estimates an excited density > 1.5 x 10^13 cm^-3 from the fluorescence. geohegan_1986 (TC-886) quotes ‘(1-2.3) x 10^-31 cm^4 W^-1’ for this transition from Bokor and co-workers and Bischel et al. ‘assuming a 100-cm-1-bandwidth ArF laser’: this paper’s 1 x 10^-31 is the lower end, for 100 cm^-1; the 2.3 x 10^-31 is not in this paper (the bokor_1980 record gives 2.34 x 10^-31 for that paper’s 25 cm^-1 laser). DOUBT: Table I prints the Kr level at ‘103,762 cm^-1’, the text (p. 386) at ‘103 363 cm^-1’; only the latter lies inside the ArF two-photon range the paper gives (103 300-103 560 cm^-1, p. 386): probably a misprint in Table I (no value of it is taken).
NOT TAKEN (no quantity of the vocabulary holds them): Table I’s bound two-photon excitation estimates of alpha (cm4/watt; H2 E,F 9 x 10^-33, CO F 5 x 10^-33, N2 E 4 x 10^-34, Kr 4p5 6p 1 x 10^-31, I2 6 x 10^-31 at 193 nm; Xe 5p5 6p 8 x 10^-32 and N2O ~3 x 10^-35 at 248 nm): linewidth-dependent peak coefficients, not the frequency-integrated two_photon_excitation_cross_section (a conversion would need the assumed line shape, an inference); the H2 measurement ‘alpha ~ 10^-32 cm4/W’ for E,F (v = 2) (p. 385); the N2O upper limit ‘alpha < 3 x 10^-34 cm4/W’ (p. 388; not a curated material); Table II (H2, HD, D2 two-photon transition ranges and emission wavelengths), Table III (H2 E,F -> B line intensities); the quenching rates and cross sections (pp. 383-389). Further two-photon data the paper cites: D. J. Kligler and C. K. Rhodes, Phys. Rev. Lett. 40, 309 (1978) (H2 E,F two-photon excitation, Ref. 1), held as kligler_1978b (TC-1043); D. Kligler, D. Pritchard, W. K. Bischel and C. K. Rhodes, J. Appl. Phys. 49, 2219 (1978) (Xe two-photon excitation at 248 nm, Ref. 10), held as kligler_1978 (TC-1021). Not in the library: B. R. Marx, J. Simons and L. Allen, J. Phys. B 11, L273 (1978) (the line-shape factor, Ref. 18).
Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
bischel_1979/alpha_Xe#
{
"id": "alpha_Xe",
"material": "Xe",
"file": "Xe/bischel_1979__alpha_Xe.csv",
"table": "tbl_246cdac4e41d",
"quantity": "multiphoton_ionization_cross_section",
"unit": "cm4 W-1",
"scale": 1e-34,
"abscissa_unit": "nm",
"use": "check",
"uncertainty": {
"level": "not stated"
},
"parameters": {
"photons": 2,
"polarization": "not stated",
"method": "estimate from second-order perturbation theory with one intermediate state (Eqs. 1-3): energy denominator 16 x 10^3 cm^-1, mu_1^2 = mu_2^2 = 1 debye^2, line width ~10^9 MHz 'estimated for photoionization continuum'",
"definition": "sigma(nu_2) = alpha I_1 (Eq. 1, p. 381) and W_fg = alpha I^2 / hbar omega (p. 382); alpha in cm^4/watt",
"wavelength_nm": 193,
"linewidth_mhz": 1000000000.0,
"linewidth_definition": "'~10^9 (g)', footnote (g): 'Estimated for photoionization continuum' (Table I)",
"energy_denominator_cm1": 16000
}
}
Table I (p. 381), xenon, 193 nm, excited product Xe+: the estimated coefficient alpha in cm4/watt (rate alpha I^2 / hbar omega; sigma_2 = alpha hbar omega = 1.03e-52 cm4 s), for the photoionisation continuum (line width ~10^9 MHz, footnote g), without the autoionising resonances, which ‘could enhance the value of alpha given in Table I by a factor of ~10^2’ (p. 386). One significant figure; an order-of-magnitude estimate.
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.