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 <https://github.com/LupoLab/optmat/blob/main/src/optmat/data/sources/ripoche_1997.toml>`__ · :doc:`Catalogue </the-data/sources>` · :doc:`Review register </register>`

DOI: `10\.1016/s0030\-4018\(96\)00675\-x <https://doi.org/10.1016/s0030-4018%2896%2900675-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
~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "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
~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "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 :doc:`review register </register>` for the checks and decisions.