ripoche_1997#
J.-F. Ripoche, G. Grillon, B. Prade, M. Franco, E. Nibbering, R. Lange and A. Mysyrowicz, “Determination of the time dependence of n2 in air”, Opt. Commun. 135, 310 (1997)
Source record · Catalogue · Review register
DOI: 10.1016/s0030-4018(96)00675-x
Source kind: measurement
Recorded technique: Cross-phase modulation pump-probe (pp. 310-311): a Ti:sapphire oscillator-amplifier at 800 nm, about 150 fs, up to 40 mJ, 15 mm beam; pump (15 mm) and weak probe (3 mm) crossed at < 0.3 degree; the probe spectrum’s centre of gravity against the pump-probe delay (twenty shots per point), fitted with a model of an instantaneous plus a delayed index response. Samples: BK7 and Herasil plates (3 mm), CS2 (2 mm cell), and 5 m of room air (-500 to 6500 fs delays).
Materials in structured entries: N2, O2
Dataset quantities: polarizability_anisotropy, rotational_constant
Contents: 4 datasets; 0 formulas.
Curation notes#
Identity checked against the first page. Page numbers are journal pages (pdf pages 1-5 = pp. 310-314).
WHAT IS TABULATED (Table 1, p. 313, ‘Values of the non-linear refractive index parameters for O2 and N2 [13]’): per gas, the concentration in air (O2 20 %, N2 80 %), the rotational constant B (cm-1: O2 1.4, N2 2.0) and the polarizability anisotropy beta(omega) = alpha_par - alpha_perp (Eq. (15)) in C2 m2/J (= C m2/V, SI: O2 1.27e-40, N2 1.0e-40). All are the model’s inputs, from Ref. [13] = C. H. Lin, J. P. Heritage, T. K. Gustafson, R. Y. Chiao and J. P. McTague, Phys. Rev. A 13, 813 (1976) (lin_1976), not measured here. Checked: lin_1976’s Table I Delta alpha, N2 9.3 and O2 11.4 x 10^-25 cm3 (from Hirschfelder, Curtiss and Bird), times 4 pi eps0 x 1e-6 are 1.035e-40 and 1.268e-40 C m2/V (printed 1.0 and 1.27), and its B, 2.001 and 1.438 cm-1, round to 2.0 and 1.4. N2 and O2 are given separately, so B and beta are datasets (reproduced); no wavelength is stated for beta (lin_1976 states none either). The concentrations (air) are notes only: air is not a material.
THE AIR RESULT (not a material; notes only). The model, Eqs. (11)-(18) (pp. 312-313): Delta n = n2,inst I + integral R(u) I(t - u) du, with the rotational Raman response R_gas(t) = n2,rot sum_J F_J sin(-omega_J t) (Eq. (13)), n2,rot = (32 pi^2 N/(h c n0)) beta^2(omega) (Eq. (14)), F_J = [rho_{J+2} - rho_J] Z_J (J + 2)(J + 1)/(2J + 3) (Eq. (16)), rho_J Boltzmann with B (Eq. (17), no centrifugal distortion), Z_J = 2 (even) and 1 (odd) for N2, and 0 (even) and 1 (odd) for O2, omega_J = 4 pi B c (2J + 3) (Eq. (18)); no dephasing (collisions ‘neglected on a picosecond time scale’, p. 312). The ‘first echo occurs approximately at t = 1/4Bc ~ 4 ps in N2 and t ~ 6 ps in O2’ (p. 313). The fit to the air data (Fig. 6) has two free parameters, r_air = n2,rot/n2,inst and the pulse length: ‘best fitted with tau_FWHM = 125 fs and r_air = 1 which corresponds to a pure rotational contribution as important as the electronic one’ (p. 314); Fig. 6’s caption prints ‘tau_FWHM = 130 fs and r_air = 1’ (125 against 130: unresolved; both pages checked). No uncertainty is given for r_air. No absolute n2 of air is given. r_air is a ratio of the model’s amplitude n2,rot (Eq. (14), the prefactor of the response) to n2,inst, not of the time-integrated rotational index to the electronic one, and the instantaneous part includes the ‘Rayleigh rotational contributions’ (p. 312).
OTHER RESULTS (notes only). Herasil: tau_FWHM = 140 fs (a pure electronic response, ‘response time shorter than 3 fs’); CS2: r1 = A1/n2,inst = 1.25 and r2 = A2/n2,inst = 16.25 with T1 = 100 fs and T2 = 1.5 ps fixed from Ref. [5] (p. 312; Fig. 2). The red shift of the pump after 5 m of air: centre of gravity 799.4 -> 806.2 nm (Fig. 3).
What this bears on: nothing new for the parameters in use: the anisotropies are lin_1976’s (Wahlstrand et al.’s are used), and the air response has no separate N2 and O2 result.
Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
ripoche_1997/table1_B_N2#
{
"id": "table1_B_N2",
"material": "N2",
"file": "N2/ripoche_1997__table1_B_N2.csv",
"table": "tbl_d9854060f4cb",
"quantity": "rotational_constant",
"unit": "cm-1",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"lin_1976"
],
"parameters": {
"constant": "B"
}
}
Table 1 (p. 313), N2: B = 2.0 cm-1, from Ref. [13] (lin_1976’s 2.001, which cites Herzberg), rounded. The vibrational state is not stated; used in Eqs. (17)-(18) as the ground-state rotational constant with no distortion term.
ripoche_1997/table1_B_O2#
{
"id": "table1_B_O2",
"material": "O2",
"file": "O2/ripoche_1997__table1_B_O2.csv",
"table": "tbl_d9854060f4cb",
"quantity": "rotational_constant",
"unit": "cm-1",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"lin_1976"
],
"parameters": {
"constant": "B"
}
}
Table 1 (p. 313), O2: B = 1.4 cm-1, from Ref. [13] (lin_1976’s 1.438), rounded. The vibrational state is not stated.
ripoche_1997/table1_anisotropy_N2#
{
"id": "table1_anisotropy_N2",
"material": "N2",
"file": "N2/ripoche_1997__table1_anisotropy_N2.csv",
"table": "tbl_d9854060f4cb",
"quantity": "polarizability_anisotropy",
"unit": "SI",
"scale": 1e-40,
"abscissa_unit": "nm",
"use": "reproduced",
"reproduced_from": [
"lin_1976",
"J. O. Hirschfelder, C. F. Curtiss and R. B. Bird, Molecular Theory of Gases and Liquids (Wiley, New York, 1954)"
]
}
Table 1 (p. 313), N2: beta(omega) = alpha_par - alpha_perp = 1.0 x 10^-40 C2 m2/J (= C m2/V), from Ref. [13]: lin_1976’s 9.3e-25 cm3 (Hirschfelder, Curtiss and Bird) is 1.035e-40 C m2/V. Wavelength not stated (the experiment is at 800 nm; the value is not measured).
ripoche_1997/table1_anisotropy_O2#
{
"id": "table1_anisotropy_O2",
"material": "O2",
"file": "O2/ripoche_1997__table1_anisotropy_O2.csv",
"table": "tbl_d9854060f4cb",
"quantity": "polarizability_anisotropy",
"unit": "SI",
"scale": 1e-40,
"abscissa_unit": "nm",
"use": "reproduced",
"reproduced_from": [
"lin_1976",
"J. O. Hirschfelder, C. F. Curtiss and R. B. Bird, Molecular Theory of Gases and Liquids (Wiley, New York, 1954)"
]
}
Table 1 (p. 313), O2: beta(omega) = 1.27 x 10^-40 C2 m2/J (= C m2/V), from Ref. [13]: lin_1976’s 11.4e-25 cm3 is 1.268e-40 C m2/V. Wavelength not stated.
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.