pigeon_2016#

J. J. Pigeon, S. Ya. Tochitsky, E. C. Welch and C. Joshi, Opt. Lett. 41, 3924 (2016)

Source record · Catalogue · Review register

Source kind: measurement

Recorded technique: Collinear nondegenerate four-wave mixing of a dual-line CO2-laser beat wave (10P20 at 10.59 um and 10R16 at 10.27 um, 882 GHz beat, 200 MW, 197 +- 21 ps FWHM, 1 Hz; UCLA Neptune laboratory) focused by a 2.5 m NaCl lens (600 um 1/e^2 spot, elliptical) into a 2 m gas cell (25 cm interaction length); first Stokes sideband (10.9 um) isolated by grating and monochromator and measured with a cooled HgCdTe detector; background from the same pressure of He (about 20 times smaller nonlinearity); quantitative data at <= 380 Torr of high-purity gas (dry air < 3 ppm water) to avoid collisional ionisation (breakdown fluorescence above 630 Torr); peak intensity about 15 GW/cm^2.

Materials in structured entries: N2, O2

Dataset quantities: nonlinear_index

Contents: 6 datasets; 0 formulas.

Curation notes#

Defining equation (p. 2): the first-Stokes energy W_10.9 = k_10.9^2 n2,eff^2 W_10.6^2 W_10.3 A_10.9 / (sqrt(3) tau^2) (int_0^L dz / (pi a b)^(3/2))^2 (Eq. 1), ‘assuming perfect phase-matching, negligible pump depletion, and a linear relationship between n2 and pressure’; k the wavenumber, A the (iris-defined, 4 mm) area of the Stokes beam, tau the pulse length, a and b the beam axes; sqrt(3) because the sideband is sqrt(3) shorter than the pump. n2,eff is taken from the difference of the sample and He slopes of W_10.9 against W_10.6^2 W_10.3 (Fig. 4). The effective index is ‘n2,eff = n2,electronic + n2,molecular’ (p. 2): with 200 ps pulses the rotational (Rayleigh, Delta J = 0) response is adiabatic, so part = total; the paper checks that the nearest Raman line (N2 J = 4 -> 2 at 840 GHz, 42 GHz from the beat) adds no resonant contribution (p. 2). The index is the single-beam n in n = n0 + n2 I implied by the FWM formula (coefficient = self; the formula’s normalisation is the paper’s). Uncertainty (p. 3): least-squares slopes of sample and background, pulse length and the beam integral, dominated by the slope fits (level not stated).

Table 1 (tbl_a7c0c0dc1804, ‘Scaled to Atmospheric Pressure’; image checked): n2,eff in 10^-19 cm^2/W. The pressure scaling from <= 380 Torr is linear (the paper’s assumption); the temperature is not stated: 101325 Pa and 293.15 K are assumed. The wavelength column is labelled 10.6 um (the pumps are 10.59 and 10.27 um). The 0.8 um column is Nibbering et al. (J. Opt. Soc. Am. B 14, 650, 1997; ref. 11) and the 2.4 um column is ‘Calculated from measurements in Zahedpour et al. using n2,eff = n2 + n2,rot’ (ref. 13, Opt. Lett. 40, 5794, 2015; footnote b, ‘+’ read from the page image): both long-pulse (total) effective values chosen to compare with the 200 ps measurement (as pigeon_2018 says, p. 4). Nibbering’s 0.8 um values quoted here (N2 3 +- 0.7, O2 8 +- 2.2) are not the instantaneous ones Loriot and Wahlstrand quote from the same paper (2.3 and 5.1), consistent with Nibbering’s long-pulse (inertial) values; check against nibbering_1997. Air (5.0 +- 0.9 at 10.6 um; 4 +- 1.1 at 0.8 um ‘calculated from measurements of N2, O2, and Ar’, footnote a) is skipped.

Other gases (p. 4): Kr and Xe gave symmetric FWM spectra with lower yield; no signal above noise in Ar. Their values are in pigeon_2018. The asymmetric (red) FWM spectrum of air shows rotational Raman scattering matters for 200 ps, 10 um pulses.

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

Datasets#

pigeon_2016/fwm_N2#

{
  "id": "fwm_N2",
  "material": "N2",
  "file": "N2/pigeon_2016__fwm_N2.csv",
  "table": "tbl_a7c0c0dc1804",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-19,
  "abscissa_unit": "um",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 293.15
  },
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "part": "total",
    "coefficient": "self",
    "pulse_fs": 197000
  }
}

Table 1, 10.6 um column: n2,eff (electronic plus molecular, 200 ps) scaled linearly from <= 380 Torr to atmospheric pressure; 293.15 K assumed.

pigeon_2016/fwm_O2#

{
  "id": "fwm_O2",
  "material": "O2",
  "file": "O2/pigeon_2016__fwm_O2.csv",
  "table": "tbl_a7c0c0dc1804",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-19,
  "abscissa_unit": "um",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 293.15
  },
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "part": "total",
    "coefficient": "self",
    "pulse_fs": 197000
  }
}

Table 1, 10.6 um column: n2,eff (electronic plus molecular, 200 ps) scaled linearly to atmospheric pressure (the O2 data of Fig. 4 were taken at 250 Torr); 293.15 K assumed.

pigeon_2016/nibbering_1997_N2#

{
  "id": "nibbering_1997_N2",
  "material": "N2",
  "file": "N2/pigeon_2016__nibbering_1997_N2.csv",
  "table": "tbl_a7c0c0dc1804",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-19,
  "abscissa_unit": "um",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 293.15
  },
  "use": "reproduced",
  "reproduced_from": [
    "nibbering_1997"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "part": "total",
    "coefficient": "self"
  }
}

Table 1, 0.8 um column (ref. 11, Nibbering et al. 1997): a long-pulse (total) value; the state is Pigeon’s ‘atmospheric pressure’. Use the nibbering_1997 record.

pigeon_2016/nibbering_1997_O2#

{
  "id": "nibbering_1997_O2",
  "material": "O2",
  "file": "O2/pigeon_2016__nibbering_1997_O2.csv",
  "table": "tbl_a7c0c0dc1804",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-19,
  "abscissa_unit": "um",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 293.15
  },
  "use": "reproduced",
  "reproduced_from": [
    "nibbering_1997"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "part": "total",
    "coefficient": "self"
  }
}

Table 1, 0.8 um column (ref. 11, Nibbering et al. 1997): a long-pulse (total) value. Use the nibbering_1997 record.

pigeon_2016/zahedpour_2015_N2#

{
  "id": "zahedpour_2015_N2",
  "material": "N2",
  "file": "N2/pigeon_2016__zahedpour_2015_N2.csv",
  "table": "tbl_a7c0c0dc1804",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-19,
  "abscissa_unit": "um",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 293.15
  },
  "use": "reproduced",
  "reproduced_from": [
    "zahedpour_2015"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "part": "total",
    "coefficient": "self"
  }
}

Table 1, 2.4 um column, footnote b: computed by Pigeon et al. from Zahedpour et al.’s (2015) n2 and n2,rot as n2,eff = n2 + n2,rot (the long-pulse sum), not printed by Zahedpour. Use the zahedpour_2015 record.

pigeon_2016/zahedpour_2015_O2#

{
  "id": "zahedpour_2015_O2",
  "material": "O2",
  "file": "O2/pigeon_2016__zahedpour_2015_O2.csv",
  "table": "tbl_a7c0c0dc1804",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-19,
  "abscissa_unit": "um",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 293.15
  },
  "use": "reproduced",
  "reproduced_from": [
    "zahedpour_2015"
  ],
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "part": "total",
    "coefficient": "self"
  }
}

Table 1, 2.4 um column, footnote b: n2 + n2,rot computed by Pigeon et al. from Zahedpour et al. (2015). Use the zahedpour_2015 record.

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.