Optical constants
Refractive index of BaF2 - Barium fluoride (CRYSTRAN)
BaF2 - Barium fluoride: n,k 0.1408–10.35 µm
- Data
- tabulated n + tabulated k
- Range
- 0.1408–10.35 µm
- Points
- 43
- Licence
- CC0-1.0
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 1.47446
- Extinction coefficient k
- 7.30570e-08
- Permittivity ε1
- 2.17403
- Permittivity ε2
- 2.15439e-07
- Absorption coefficient α
- 0.0156239 cm⁻¹
- Penetration depth δ = λ/(2πk)
- 1.28009e+09 nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.0347222 µm⁻¹
- Group index ng
- 1.49486
- Group velocity dispersion
- — fs²/mm
- Dispersion parameter D
- — ps/(nm·km)
- Photon energy
- 2.11001 eV
ε = (n + ik)², α = 4πk/λ, ng = n − λ dn/dλ, GVD = λ³/(2πc²) d²n/dλ², D = −(λ/c) d²n/dλ². Group-velocity dispersion is given for formula data only.
Use it in Lightsmith
Load this data in Python, simulate in one more line
pip install lightsmith
import lightsmith as ls
# BaF2 - Barium fluoride (CRYSTRAN): BaF2 - Barium fluoride
crystran_baf2 = ls.fetch_refractiveindex("specs", "CRYSTRAN-optical", "BaF2", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(crystran_baf2.range_nm) # (140.8, 10346) nm
eps = crystran_baf2.eps([633]) # complex permittivityDownloads the original record once (pinned to the imported snapshot) and caches it.
import json, urllib.request
import lightsmith as ls
url = "https://materials.lightsmith.dev/v1/datasets/ds_fa4de5262249/lightsmith"
crystran_baf2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(crystran_baf2.source) # citation and provenance travel with the dataAny dataset here, as the library's Tabulated material (crystran-baf2/crystran).
# ... load crystran_baf2 as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=crystran_baf2)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=1000, num=81),
)
res = ls.solve(sim) # exact Mie for a sphere
print(res.q_ext) # extinction efficiency at each wavelengthSame spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).
Lightsmith is open source (MIT): Mie, T-matrix, BEM, DDA, FDTD, RCWA, TMM, mode solvers and inverse design behind one spec, on CPU or GPU. GitHub.
Comments and conditions
Properties
- density
- value: 4890
- thermal dispersion
- type: constant, value: -1.52e-05
- thermal expansion
- value: 1.81e-05, temperature: 273
- hardness
- type: Knoop, value: 8.04e8
- melting point
- value: 1641
- thermal conductivity
- value: 11.72, temperature: 286
- youngs modulus
- value: 53.07e9
- poissons ratio
- value: 0.343
- solubility
- value: 1.7, temperature: 296
Thermo-optic coefficient
- dn/dT = -1.52e-05 K⁻¹
References
See also Crystran BaF2 online data sheet
Cite
Crystran Ltd. The Crystran handbook of infra-red and ultra-violet optical materials (5th edition, 2023); See also Crystran BaF2 online data sheet; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
Computed on 43 wavelengths, the same grid as the API and the library| λ (µm) | n | k |
|---|---|---|
| 0.1408 | 1.815 | 6.154000e-07 |
| 0.1452 | 1.782 | 4.992000e-07 |
| 0.1477 | 1.767 | 4.474000e-07 |
| 0.15 | 1.678 | 4.040000e-07 |
| 0.2 | 1.557 | 1.140000e-07 |
| 0.2652 | 1.5122 | 8.537328e-08 |
| 0.2803 | 1.5066 | 8.479643e-08 |
| 0.2893 | 1.5039 | 8.445262e-08 |
| 0.2967 | 1.5019 | 8.416993e-08 |
| 0.3021 | 1.5 | 8.396364e-08 |
| 0.313 | 1.4978 | 8.354724e-08 |
| 0.3254 | 1.4952 | 8.307354e-08 |
| 0.3403 | 1.4925 | 8.250433e-08 |
| 0.3466 | 1.4915 | 8.226366e-08 |
| 0.361 | 1.4894 | 8.171355e-08 |
| 0.3663 | 1.4887 | 8.151108e-08 |
| 0.4046 | 1.4844 | 8.004796e-08 |
| 0.5461 | 1.4759 | 7.464241e-08 |
| 0.5893 | 1.4744 | 7.299209e-08 |
| 0.6438 | 1.473 | 7.091010e-08 |
| 0.6563 | 1.4727 | 7.043257e-08 |
| 0.7065 | 1.4718 | 6.851485e-08 |
| 0.8521 | 1.4699 | 6.295267e-08 |
| 0.8944 | 1.4694 | 6.133674e-08 |
| 1.014 | 1.4685 | 5.676781e-08 |
| 1.1287 | 1.4678 | 5.238607e-08 |
| 1.3673 | 1.4667 | 4.327113e-08 |
| 1.5295 | 1.4661 | 3.707480e-08 |
| 1.681 | 1.4656 | 3.128724e-08 |
| 1.7012 | 1.4655 | 3.051556e-08 |
| 1.9701 | 1.4647 | 2.024311e-08 |
| 2.3254 | 1.4636 | 6.670026e-09 |
| 2.6738 | 1.4623 | 0 |
| 3.2434 | 1.4602 | 0 |
| 3.422 | 1.4594 | 0 |
| 5.138 | 1.4501 | 0 |
| 5.549 | 1.4473 | 0 |
| 6.238 | 1.4422 | 0 |
| 6.6331 | 1.439 | 0 |
| 7.0442 | 1.4353 | 0 |
| 7.268 | 1.4331 | 0 |
| 9.724 | 1.4051 | 3.958000e-06 |
| 10.346 | 1.3936 | 1.041160e-05 |
Optical transmission calculator
Free-standing sample in vacuum, normal incidence- Transmittance T
- —
- Reflectance R
- —
Fresnel reflection calculator
- Rp
- —
- Rs
- —
- R = (Rp+Rs)/2
- —
- Phase φp
- —
- Phase φs
- —
- Brewster angle θB
- —
- Critical angle θC
- —
Barium Fluoride is grown by vacuum Stockbarger technique. Unlike CaF2, BaF2 is not found in the native state and all material must be synthesised chemically making BaF2 relatively expensive to produce. Barium Fluoride cleaves easily and is highly susceptible to thermal shock. It polishes well and can be etched (5). The highest purity Barium Fluoride VUV material can be qualified as fast scintillator grade (6). The highest purity Barium Fluoride VUV material can be qualified as fast scintillator grade (6).
REFERENCES:
(1) Handbook Optical Constants, ed Palik, V3, ISBN 0-12-544423-0
(2) I.H.Malitson; J.Opt.Soc.Am. Vol52, p1377, 1962
(3) D.Girlich; Elastic Constants of BaF2; Phys.Rev. Vol135, p1826, 1964
(4) S.Ballard et al; J.Opt.Soc.Am. Vol42, p684, 1952
(5) US patent. Chemical polish. 4,040,896 1977
(6) M.Laval et al; Nu. Insts.Meth, V206 p169, 1983