wahlstrand_2015#

J. K. Wahlstrand, S. Zahedpour, Y.-H. Cheng, J. P. Palastro and H. M. Milchberg, “Absolute measurement of the ultrafast nonlinear electronic and rovibrational response in H2 and D2”, Phys. Rev. A 92, 063828 (2015)

Source record · Catalogue · Review register

DOI: 10.1103/PhysRevA.92.063828

Source kind: measurement

Recorded technique: Single-shot supercontinuum spectral interferometry: 3-mJ, 40-fs pump near 800 nm; supercontinuum probe and reference (500-700 nm, from ~2.5 atm SF6 or Xe; chirp beta2 = 1675 fs^2, beta3 = 396 fs^3, omega0 = 3.05 fs^-1), collinear with the pump; thin laser-drilled gas-flow tube (absolute, calibrated as in wahlstrand_2012) or backfilled chamber (~0.3 atm). Rotational parameters (B, D, Delta alpha) from the delayed response (pulse widths varied at fixed 34 uJ); the vibrational part separated from the electronic one through the resonant two-beam-coupling phase shift as a function of the pump-probe beat frequency Delta omega (chirped probe), fitted with a one-mode rovibrational density-matrix model (pp. 2-5).

Materials in structured entries: D2, H2

Dataset quantities: nonlinear_index, polarizability_anisotropy

Contents: 14 datasets; 0 formulas.

Curation notes#

Journal pages 063828-1 to -10 = PDF pages 1-10. Identity checked against the first page. H2 and D2.

DEFINING EQUATIONS (Gaussian). p. 1: Delta n(x, t) = (k0 L_eff)^-1 Delta Phi(x, t), k0 the probe central wavenumber. p. 4: the probe’s instantaneous polarization P_p^inst = chi_eff A_p exp[i(k_p.r - omega_p t)] with ‘2 pi chi_eff = Delta n = n2 I_e’, n2 = n2,elec + n2,vib, n2,vib = n2,vib^s + n2,vib^g; ‘for a nonresonant electronic response, the smooth and grating terms are the same, so n2,elec = n2,elec^s + n2,elec^g = 2 n2,elec^s. The nonlinear refractive index for a weak probe pulse is a factor of 2 larger than for a pulse acting on itself [19]’ (p. 4). So the tabulated n2,elec^s is the SELF coefficient. Eqs. (8)-(9), p. 4 (cw limit): n2,vib^s = 4 pi^2 N (d alpha/dQ)^2 / (n0 c mu Omega_v^2), n2,vib^g = 4 pi^2 N (d alpha/dQ)^2 / [n0 c mu (Omega_v^2 - Delta omega^2)], alpha = alpha_par/3 + 2 alpha_perp/3, mu the reduced mass; Eq. (10) the finite-pulse grating term (Dawson function). Probe prompt index n2,prompt = 2 n2,elec^s + n2,vib^s + n2,vib^g (p. 5). Effective n2 of a pulse I(t) = I0 g(t), Eq. (11), p. 6. Long-pulse total (p. 6): n2,tot = n2,elec^s + n2,rot + n2,vib; the rotational adiabatic n2,rot as in [22] = wahlstrand_2012. No chi(3) or gamma is defined.

TABLE I (p. 5; image checked, the cells file matches; extracted by tools/extract/wahlstrand_2015.py). Caption: ‘Measured electronic Kerr coefficient n2,elec^s at 1 atm (at probe wavelength of 600 nm and pump wavelength of 800 nm), polarizability anisotropy Delta alpha, and polarizability derivative d alpha/dQ ... The rightmost column shows n2 estimates at 1 atm based on our experimental results for a long pulse at 800 nm.’ d alpha/dQ (1e-16 cm2), not extracted (no quantity): this experiment H2 1.3 +- 0.2, D2 1.4 +- 0.3; Ref. [31] (Bishop and Pipin 1993) H2 1.24; Ref. [39] (Raman scattering) H2 1.30 +- 0.10, D2 1.22 +- 0.10. Check: n2,elec^s + n2,rot + n2,vib = n2,tot (H2 6.5 + 2.7 + 1.0 = 10.2; D2 5.8 + 3.9 + 1.2 = 10.9). Which vibrational coefficient (smooth or smooth + grating) the long-pulse n2,vib is, is not stated; for a pulse acting on itself it should be the smooth one (TC-279).

PART. n2,elec^s is electronic: the vibrational part is separated through the resonant two-beam coupling (not by pulse duration), the rotational part by its delay. The vibrational response is effectively instantaneous for pulses longer than ~8 fs (H2) and ~12 fs (D2); the rotational one adiabatic above ~100 fs (H2) and ~200 fs (D2) (p. 6).

REFERENCE STATE. 1 atm (Table I caption), no temperature. The measurements are ‘calibrated as in wahlstrand_2012’, whose N2 flow calibration corresponds to 290.9 K at 1 atm (TC-316): this paper’s own values are recorded at 101325 Pa, 290.9 K; the Shelton and Rice column, the authors’ computation, at 293.15 K (assumed). Normal (thermal ortho/para) H2 and D2 at room temperature assumed.

TEXT (not extracted). Fits (p. 2): B = 58.9 (+- 3.0) cm^-1, D = 0.05 (+- 0.02) cm^-1 for H2; B = 29.3 (+- 1.5), D = 0.021 (+- 0.008) cm^-1 for D2 (‘in good agreement with the literature values’). Vibrational constants used (p. 5): H2 omega_e = 0.829 fs^-1, omega_e x_e = 0.023 fs^-1; D2 0.567, 0.012 fs^-1 (Huber and Herzberg); Omega_v = 0.783 (H2), 0.543 fs^-1 (D2). The prompt response of H2 and D2 is linear in intensity up to the ionization threshold (~80 TW/cm2 used; ~1e14 W/cm2). Uncertainty: ‘The most important source of error is the determination of the pump laser intensity’ (p. 5).

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

Datasets#

wahlstrand_2015/n2_elec_H2#

{
  "id": "n2_elec_H2",
  "material": "H2",
  "file": "H2/wahlstrand_2015__n2_elec_H2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 290.9
  },
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "part": "electronic",
    "coefficient": "self",
    "pulse_fs": 40,
    "probe_nm": 600
  }
}

Table I, n2,elec^s ‘This expt.’: the electronic self coefficient at 1 atm (290.9 K, the density of the N2 flow calibration, as wahlstrand_2012; TC-316), pump 800 nm, probe 600 nm; vibrational part separated by resonant two-beam coupling, rotational part by its delay.

wahlstrand_2015/n2_shelton_rice_H2#

{
  "id": "n2_shelton_rice_H2",
  "material": "H2",
  "file": "H2/wahlstrand_2015__n2_shelton_rice_H2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 293.15
  },
  "use": "check",
  "reproduced_from": [
    "shelton_1994"
  ],
  "parameters": {
    "part": "electronic",
    "coefficient": "self"
  }
}

Table I, n2,elec^s ‘Ref. [35]’ (Shelton and Rice, Chem. Rev. 94, 3 (1994)): an n2 the authors derived from Shelton and Rice’s electronic hyperpolarizability; the computation (dispersion, density) is not stated. Comparison value.

wahlstrand_2015/dalpha_H2#

{
  "id": "dalpha_H2",
  "material": "H2",
  "file": "H2/wahlstrand_2015__dalpha_H2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "polarizability_anisotropy",
  "unit": "cm3",
  "scale": 1e-25,
  "abscissa_unit": "nm",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  }
}

Table I, Delta alpha ‘This expt.’ (1e-25 cm3): fitted to the absolute rotational response (t > 200 fs) with density-matrix simulations using the measured B and D. The rotational signal scales as Delta alpha(pump) x Delta alpha(probe): wavelength recorded as the pump’s (800 nm), probe 600 nm.

wahlstrand_2015/dalpha_bridge_buckingham_H2#

{
  "id": "dalpha_bridge_buckingham_H2",
  "material": "H2",
  "file": "H2/wahlstrand_2015__dalpha_bridge_buckingham_H2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "polarizability_anisotropy",
  "unit": "cm3",
  "scale": 1e-25,
  "abscissa_unit": "nm",
  "use": "reproduced",
  "reproduced_from": [
    "N. J. Bridge and A. D. Buckingham, Proc. R. Soc. London, Ser. A 295, 334 (1966)"
  ]
}

Table I, Delta alpha ‘Ref. [30]’: N. J. Bridge and A. D. Buckingham, Proc. R. Soc. London, Ser. A 295, 334 (1966) (light-scattering depolarization; not in the library). Its wavelength is not stated here.

wahlstrand_2015/n2_rot_H2#

{
  "id": "n2_rot_H2",
  "material": "H2",
  "file": "H2/wahlstrand_2015__n2_rot_H2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 290.9
  },
  "use": "check",
  "parameters": {
    "part": "rotational",
    "coefficient": "self"
  }
}

Table I, rightmost columns (‘n2 at 800 nm ... for a long pulse’): n2,rot: the adiabatic (long-pulse) rotational coefficient computed from the measured Delta alpha (expression as in wahlstrand_2012); 1 atm (290.9 K, as the measured values). Derived from this paper’s measured parameters, not measured directly: ‘check’. Applies to pulses longer than ~100 fs (H2) or ~200 fs (D2) for the rotational part.

wahlstrand_2015/n2_vib_H2#

{
  "id": "n2_vib_H2",
  "material": "H2",
  "file": "H2/wahlstrand_2015__n2_vib_H2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 290.9
  },
  "use": "check",
  "parameters": {
    "part": "vibrational",
    "coefficient": "self"
  }
}

Table I, rightmost columns (‘n2 at 800 nm ... for a long pulse’): n2,vib: the adiabatic vibrational coefficient computed from the measured d alpha/dQ (Eq. (8)); 1 atm (290.9 K, as the measured values). Derived from this paper’s measured parameters, not measured directly: ‘check’. Applies to pulses longer than ~100 fs (H2) or ~200 fs (D2) for the rotational part.

wahlstrand_2015/n2_tot_H2#

{
  "id": "n2_tot_H2",
  "material": "H2",
  "file": "H2/wahlstrand_2015__n2_tot_H2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 290.9
  },
  "use": "check",
  "parameters": {
    "part": "total",
    "coefficient": "self"
  }
}

Table I, rightmost columns (‘n2 at 800 nm ... for a long pulse’): n2,tot = n2,elec^s + n2,rot + n2,vib, the long-pulse total; 1 atm (290.9 K, as the measured values). Derived from this paper’s measured parameters, not measured directly: ‘check’. Applies to pulses longer than ~100 fs (H2) or ~200 fs (D2) for the rotational part.

wahlstrand_2015/n2_elec_D2#

{
  "id": "n2_elec_D2",
  "material": "D2",
  "file": "D2/wahlstrand_2015__n2_elec_D2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 290.9
  },
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  },
  "parameters": {
    "part": "electronic",
    "coefficient": "self",
    "pulse_fs": 40,
    "probe_nm": 600
  }
}

wahlstrand_2015/n2_shelton_rice_D2#

{
  "id": "n2_shelton_rice_D2",
  "material": "D2",
  "file": "D2/wahlstrand_2015__n2_shelton_rice_D2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 293.15
  },
  "use": "check",
  "reproduced_from": [
    "shelton_1994"
  ],
  "parameters": {
    "part": "electronic",
    "coefficient": "self"
  }
}

wahlstrand_2015/dalpha_D2#

{
  "id": "dalpha_D2",
  "material": "D2",
  "file": "D2/wahlstrand_2015__dalpha_D2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "polarizability_anisotropy",
  "unit": "cm3",
  "scale": 1e-25,
  "abscissa_unit": "nm",
  "use": "primary",
  "uncertainty": {
    "column": true,
    "level": "not stated"
  }
}

wahlstrand_2015/dalpha_bridge_buckingham_D2#

{
  "id": "dalpha_bridge_buckingham_D2",
  "material": "D2",
  "file": "D2/wahlstrand_2015__dalpha_bridge_buckingham_D2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "polarizability_anisotropy",
  "unit": "cm3",
  "scale": 1e-25,
  "abscissa_unit": "nm",
  "use": "reproduced",
  "reproduced_from": [
    "N. J. Bridge and A. D. Buckingham, Proc. R. Soc. London, Ser. A 295, 334 (1966)"
  ]
}

wahlstrand_2015/n2_rot_D2#

{
  "id": "n2_rot_D2",
  "material": "D2",
  "file": "D2/wahlstrand_2015__n2_rot_D2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 290.9
  },
  "use": "check",
  "parameters": {
    "part": "rotational",
    "coefficient": "self"
  }
}

wahlstrand_2015/n2_vib_D2#

{
  "id": "n2_vib_D2",
  "material": "D2",
  "file": "D2/wahlstrand_2015__n2_vib_D2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 290.9
  },
  "use": "check",
  "parameters": {
    "part": "vibrational",
    "coefficient": "self"
  }
}

wahlstrand_2015/n2_tot_D2#

{
  "id": "n2_tot_D2",
  "material": "D2",
  "file": "D2/wahlstrand_2015__n2_tot_D2.csv",
  "table": "tbl_64c4c34f908d",
  "quantity": "nonlinear_index",
  "unit": "cm2/W",
  "scale": 1e-20,
  "abscissa_unit": "nm",
  "state": {
    "pressure_pa": 101325.0,
    "temperature_k": 290.9
  },
  "use": "check",
  "parameters": {
    "part": "total",
    "coefficient": "self"
  }
}

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.