farrow_1985#
R. L. Farrow and L. A. Rahn, J. Opt. Soc. Am. B 2, 903 (1985)
Source record · Catalogue · Review register
Source kind: measurement
Recorded technique: Crossed-beam, polarization-resolved CARS with a frequency-doubled Nd:YAG pump (532 nm; single axial mode <= 0.01 cm^-1, or multimode 0.7 cm^-1) and a pulsed dye probe (Stokes, <= 0.03 cm^-1); fully resolved N2 Q-branch spectra in 1.00 % N2 in Ar and the O(18) line of pure N2, 297 K, 200-1000 Torr, fitted with theoretical spectra (Schrotter and Klockner’s Q-branch cross section, argon-broadened linewidths measured by inverse Raman spectroscopy, Table 1) to find the nonresonant susceptibility relative to the N2 resonant one.
Materials in structured entries: Ar, N2
Dataset quantities: nonlinear_susceptibility, raman_linewidth
Contents: 10 datasets; 0 formulas.
Curation notes#
Nonresonant CARS susceptibilities of Ar and N2 referenced to the N2 Raman resonance (the paper’s main subject is the convolution of CARS spectra with multimode pumps; Table 3’s concentration errors are not extracted). Table 1’s N2-Ar collisional-broadening coefficients are the Raman dataset table1_Ar (added 2026-09-26, TC-439; see its notes).
Definition: Table 2’s caption: ‘chi_nr measurements expressed using the definition of relation (1)’, Yuratich’s expression, relation (1), p. 903: I_4 proportional to the integral of |sum_j K_j L_j(w1 - w3) + chi_nr|^2 I_1 I_2 I_3, with L_j = gamma_j/(w_j - w + w_3 - i gamma_j) and K_j = c^4 Delta N_j (d sigma/d Omega)_j / (hbar w_3^4 gamma_j), i.e. the CARS-literature susceptibility per unit volume, chi^CARS (Rosasco and Hurst’s Eq. (A4), whose P(w_as) = (1/4) chi^CARS E_L^2 E_s*, Eq. (A5), with the E/2 amplitude convention). The paper does not print the density; the values are per amagat (2.687e19 cm^-3): Table 2’s Ref. 13 column equals 3 x Lundeen et al.’s per-molecule chi x 2.687e19 (Ar 131e-39 -> 10.56, N2 105e-39 -> 8.46, N2 +-14 -> +-1.13, printed 10.6, 8.5 +- 1.1) and its Ref. 12 column equals 12 x Rosasco and Hurst’s 3 sigma/24 at 1 amagat (Ar 0.788 -> 9.46, printed 9.5), as Rosasco and Hurst’s (A6)-(A7) and (A26)-(A28) require (checked 2026-09-26). Hence chi^CARS = 12 chi_1111 = 3 sigma/2 = N0 gamma_T/2 at 1 amagat: gamma_T = 2 chi^CARS/N0 (1e-18 cm^3/erg per amagat = 7.443e-38 esu = 147.8 au). These are nonlinear susceptibilities per amagat, without a state (unit recorded as cm3/(erg amagat), as Farrow et al. 1987 and Hahn and Lee 1995 print it; this paper prints only ‘cm^3/erg’).
Results (p. 904): fitting the resolved spectra required reducing Hall and Eckbreth’s chi_nr (Rado rescaled: Ar 11.6, N2 10.1, Figs. 1, 2) by 17 % for Ar (+-6 % from the fit) and 16 +- 8 % for N2: chi_nr = 9.6 +- 1.0 (Ar) and 8.5 +- 0.9 (N2) x 10^-18 cm^3/erg in the text, but Table 2 prints N2 8.5 +- 1.3 (image checked): the uncertainties disagree, unresolved; the table’s is recorded. The N2 value comes from the O(18) line (linewidth 0.05 +- 0.007 cm^-1 HWHM at 1000 Torr, inferred from the CARS spectrum), the Ar value from the Q branch of 1 % N2 in Ar with IRS-measured widths. ‘Our error bounds for the chi_nr of nitrogen arise predominantly from uncertainties in linewidth, the dependence of chi_r on the Raman depolarization ratio as well as the cross section, and the moderate temperature sensitivity of the J = 18 state’ (p. 904).
Part: the CARS nonresonant background; for Ar electronic; for N2 the background near its Raman lines, i.e. electronic plus small off-resonant Raman contributions not separated (Lundeen et al. compute -3 and +3 of 105 for the vibrational and rotational tails at 4155 cm^-1): recorded electronic, with that caveat. The orientational term does not enter CARS at these detunings.
Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
farrow_1985/this_work_Ar#
{
"id": "this_work_Ar",
"material": "Ar",
"file": "Ar/farrow_1985__this_work_Ar.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "vacuum",
"use": "primary",
"uncertainty": {
"column": true,
"level": "not stated"
},
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column This Work: 9.6 +- 1.0 (Q branch of 1 % N2 in Ar, 532 nm pump). CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/this_work_N2#
{
"id": "this_work_N2",
"material": "N2",
"file": "N2/farrow_1985__this_work_N2.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "vacuum",
"use": "primary",
"uncertainty": {
"column": true,
"level": "not stated"
},
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column This Work: 8.5 +- 1.3 (the text, p. 904, says +- 0.9; O(18) of pure N2, 532 nm pump). CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/hall_eckbreth_Ar#
{
"id": "hall_eckbreth_Ar",
"material": "Ar",
"file": "Ar/farrow_1985__hall_eckbreth_Ar.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "vacuum",
"use": "reproduced",
"reproduced_from": [
"R. J. Hall and A. C. Eckbreth, in Laser Applications, Vol. 5, edited by J. F. Ready and R. K. Erf (Academic, New York, 1984), p. 213"
],
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column Ref. 1 (Hall and Eckbreth): ‘scaled from the results of Rado and thus simply represent a correction factor different from that discussed in Ref. 13’, ‘currently the most widely used values’ (note a). Rado’s ruby experiment (694.3 nm); no uncertainty. CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/hall_eckbreth_N2#
{
"id": "hall_eckbreth_N2",
"material": "N2",
"file": "N2/farrow_1985__hall_eckbreth_N2.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "vacuum",
"use": "reproduced",
"reproduced_from": [
"R. J. Hall and A. C. Eckbreth, in Laser Applications, Vol. 5, edited by J. F. Ready and R. K. Erf (Academic, New York, 1984), p. 213"
],
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column Ref. 1 (Hall and Eckbreth), Rado rescaled (note a); 694.3 nm; no uncertainty. CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/rosasco_hurst_Ar#
{
"id": "rosasco_hurst_Ar",
"material": "Ar",
"file": "Ar/farrow_1985__rosasco_hurst_Ar.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "standard_air",
"use": "reproduced",
"reproduced_from": [
"rosasco_1985"
],
"uncertainty": {
"column": true,
"level": "not stated"
},
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column Ref. 12 (Rosasco and Hurst, ‘to be published’; = rosasco_1985, whose Table IV 3 sigma/24 = 0.788 x 12 = 9.46): phase-modulated cw coherent Raman, 676.4 nm pump (Kr-ion line, standard air). CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/lundeen_Ar#
{
"id": "lundeen_Ar",
"material": "Ar",
"file": "Ar/farrow_1985__lundeen_Ar.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "vacuum",
"use": "reproduced",
"reproduced_from": [
"lundeen_1983"
],
"uncertainty": {
"column": true,
"level": "not stated"
},
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column Ref. 13 (Lundeen et al.): their 131e-39 cm^6/(erg molecule) x 3 x 2.687e19 = 10.56; 532 nm pump. CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/lundeen_N2#
{
"id": "lundeen_N2",
"material": "N2",
"file": "N2/farrow_1985__lundeen_N2.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "vacuum",
"use": "reproduced",
"reproduced_from": [
"lundeen_1983"
],
"uncertainty": {
"column": true,
"level": "not stated"
},
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column Ref. 13 (Lundeen et al.): their (105 +- 14)e-39 x 3 x 2.687e19 = 8.46 +- 1.13; 532 nm pump. CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/rado_lundeen_Ar#
{
"id": "rado_lundeen_Ar",
"material": "Ar",
"file": "Ar/farrow_1985__rado_lundeen_Ar.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "vacuum",
"use": "reproduced",
"reproduced_from": [
"lundeen_1983",
"W. G. Rado, Appl. Phys. Lett. 11, 123 (1967)"
],
"uncertainty": {
"column": true,
"level": "not stated"
},
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column Ref. 11 (Rado) ‘as scaled by’ Lundeen et al. (p. 905): Lundeen’s Rado column (Ar 118) x 3 x 2.687e19 = 9.51; ruby 694.3 nm. CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/rado_lundeen_N2#
{
"id": "rado_lundeen_N2",
"material": "N2",
"file": "N2/farrow_1985__rado_lundeen_N2.csv",
"table": "tbl_0abf9a86f7ed",
"quantity": "nonlinear_susceptibility",
"unit": "cm3/(erg amagat)",
"scale": 1e-18,
"abscissa_unit": "nm",
"wavelength_medium": "vacuum",
"use": "reproduced",
"reproduced_from": [
"lundeen_1983",
"W. G. Rado, Appl. Phys. Lett. 11, 123 (1967)"
],
"uncertainty": {
"column": true,
"level": "not stated"
},
"parameters": {
"process": "cars",
"convention": "chi_cars_per_amagat",
"part": "electronic"
}
}
Table 2 (p. 904), chi_nr in 10^-18 cm^3/erg per amagat (the CARS chi^CARS of relation (1); gamma_T = 2 chi^CARS/N0, about 148 au per unit; see the source notes), column Ref. 11 (Rado) as scaled by Lundeen et al.: N2 is that scaling’s reference (105 +- 14 -> 8.46); the +- 0.8 is not Lundeen’s +- 1.1: unexplained; ruby 694.3 nm. CARS chi(-w_as; w_p, w_p, -w_s).
farrow_1985/table1_Ar#
{
"id": "table1_Ar",
"material": "N2",
"file": "N2/farrow_1985__table1_Ar.csv",
"table": "tbl_da579f77cd0b",
"quantity": "raman_linewidth",
"unit": "cm-1/atm",
"scale": 0.001,
"abscissa": "label",
"use": "primary",
"excluded_rows": {
"Q(0)": "printed '55^a', note a 'Extrapolated' (the paper's extrapolation, not a measurement)",
"Q(1)": "printed '46^a', note a 'Extrapolated' (the paper's extrapolation, not a measurement)"
},
"uncertainty": {
"column": true,
"level": "not stated"
},
"parameters": {
"transition": "Q(J), v = 0 -> 1, per row",
"width": "hwhm",
"perturber": "Ar"
}
}
Table 1 (p. 904), ‘Argon Collisional-Broadening Coefficients for Nitrogen Q-Branch Transitions (HWHM x 10^3 cm^-1)’: the HALF width at half maximum of the N2 Q(J) lines (v = 0 -> 1) per unit pressure of Ar, ‘pressure-broadening coefficients’ (p. 904). The caption prints only ‘cm^-1’; per atm is inferred: the text (p. 906) gives HWHM ‘of the order of 0.015 cm^-1’ for 1-5 % N2 in Ar at 300 Torr (0.395 atm), i.e. about 0.038 cm^-1/atm, as the table’s mid-J values. Measured by high-resolution inverse Raman spectroscopy (Ref. 8) in a 25 % N2-in-Ar mixture, ‘correcting for the nitrogen-nitrogen broadening using the nitrogen self-broadening coefficients reported by Rosasco’ (Ref. 9: Rosasco, Lempert, Hurst and Fein, Chem. Phys. Lett. 97, 435 (1983) = rosasco_1983, whose Table 1 gives the N2 self-broadening HWHM per atm at 298 K, J = 0-18; curated 2026-09-27), p. 904. The IRS temperature is not stated (the CARS measurements are at 297 K). The ‘(n)’ is the error in the last digit, its level not stated. J = 0, 1 are extrapolated (excluded). Added 2026-09-26 (TC-439).
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.