ermolov_2015#

A. Ermolov, K. F. Mak, M. H. Frosz, J. C. Travers and P. St.J. Russell, Phys. Rev. A 92, 033821 (2015)

Source record · Catalogue · Review register

Source kind: fit

Recorded technique: A three-term ‘modified Sellmeier equation’ for helium fitted to published refractive-index data down to 90 nm (Huber & Tondello 1974 is the one cited).

Materials in structured entries: He

Dataset quantities: None recorded.

Contents: 0 datasets; 1 formula.

Curation notes#

No datasets: the paper’s only refractive-index content is its helium formula (Eq. (3) and Table I). Table I (tbl_a8db8f8174bd) lost its header row in extraction (the first coefficient pair became the header); the six coefficients are read from the table image. Luna’s :He/:HeJ (PhysData.jl) uses the same coefficients with more digits (2.16463842e-05, -6.80769781e-04, ...), recorded under source luna_physdata. The paper states the formula is ‘for helium at 1 bar and 273 K’ with rho ‘the gas density relative to 1 bar at 273 K’; solprop instead references it to 1 atm because it then agrees with Mansfield & Peck (1969) to 0.13 %. The data comparison here will say which state the fit really corresponds to.

Third-order values: none printed. The simulations (a multimode, carrier-resolved unidirectional propagation equation with the Kerr effect, self-focusing, ionisation and plasma, ref. 50) state only ‘The nonlinear refractive index data was taken from [51]’ (pdf p. 4), ref. 51 being Lehmeier, Leupacher & Penzkofer, Opt. Commun. 56, 67 (1985) (record lehmeier_1985: THG hyperpolarizabilities at 1055 nm, P = 4 eps0 chi E E E), for the He and Ne fillings; no value, convention or conversion is given. The other nonlinear citation, ref. 25 (Boling, Glass & Owyoung, IEEE J. Quantum Electron. 14, 601 (1978)), concerns optical solids and is cited only for the trend of lower nonlinearity with higher ionisation potential. No third-order dataset is added.

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

Datasets#

No datasets are recorded.

Formulas#

ermolov_2015/sellmeier_He#

{
  "id": "sellmeier_He",
  "material": "He",
  "equation": "Eq. (3) and Table I, p. 5",
  "printed": "n0^2(lambda) - 1 = rho sum_{i=1}^3 B_i lambda^2 / (lambda^2 - C_i); B1 = 2.16463e-5, C1 = -6.8077e-4, B2 = 2.10561e-7, C2 = 5.13251e-3, B3 = 4.75093e-5, C3 = 3.18621e-3",
  "variable": "lambda: wavelength in um; rho: density relative to 1 bar at 273 K",
  "form": "n2_sellmeier",
  "terms": {
    "B": [
      "2.16463e-5",
      "2.10561e-7",
      "4.75093e-5"
    ],
    "C": [
      "-6.8077e-4",
      "5.13251e-3",
      "3.18621e-3"
    ]
  },
  "state": "1bar_0C",
  "density": "real",
  "range_nm": [
    90.0,
    1000.0
  ],
  "check": "Not checkable against the paper, which prints no values of n."
}

C1 < 0 puts the first ‘pole’ at an imaginary wavelength: the term is a smooth background, not a resonance. The paper states no range; 90 nm is the short end of the data it cites, 1000 nm the long end of what Luna PR #425 and solprop assume. 273 K is read as 273.15 K.

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.