Optical constants
Refractive index of LaF3 - Lanthanum fluoride (o) (CRYSTRAN)
LaF3 - Lanthanum fluoride (o): n,k 0.254–0.547 µm
- Data
- tabulated n + tabulated k
- Range
- 0.254–0.547 µm
- Points
- 4
- Optical axis
- o
- Licence
- CC0-1.0
Uniaxial crystal, axes: oe
Plot
Click the plot to set the calculator wavelength. Note: k data cover 256-15000 nm only; k = 0 elsewhere in the n range 254-547 nm.
At one wavelength
- Refractive index n
- 1.62605
- Extinction coefficient k
- 5.71340e-08
- Permittivity ε1
- 2.64405
- Permittivity ε2
- 1.85806e-07
- Absorption coefficient α
- 0.0192484 cm⁻¹
- Penetration depth δ = λ/(2πk)
- 1.03905e+09 nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.251656 µm⁻¹
- Group index ng
- 1.71992
- Group velocity dispersion
- — fs²/mm
- Dispersion parameter D
- — ps/(nm·km)
- Photon energy
- 3.32397 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
# LaF3 - Lanthanum fluoride (o) (CRYSTRAN): LaF3 - Lanthanum fluoride (o)
crystran_laf3_o = ls.fetch_refractiveindex("specs", "CRYSTRAN-optical", "LaF3-o", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(crystran_laf3_o.range_nm) # (254, 547) nm
eps = crystran_laf3_o.eps([373]) # 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_039824499bcc/lightsmith"
crystran_laf3_o = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(crystran_laf3_o.source) # citation and provenance travel with the dataAny dataset here, as the library's Tabulated material (crystran-laf3-o/crystran).
# ... load crystran_laf3_o as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=crystran_laf3_o)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=547, 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
Conditions
- direction
- o
Properties
- density
- value: 5940
- thermal expansion
- value: 11e-06, direction: para, temperature: 298; value: 15.8e-06, direction: perp, temperature: 298
- hardness
- type: Moh, value: 4.5
- melting point
- value: 1766
- thermal conductivity
- value: 5.1, temperature: 300
- solubility
- value: 0
- k data cover 256-15000 nm only; k = 0 elsewhere in the n range 254-547 nm
References
See also Crystran LaF3 online data sheet
Cite
Crystran Ltd. The Crystran handbook of infra-red and ultra-violet optical materials (5th edition, 2023); See also Crystran LaF3 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 4 wavelengths, the same grid as the API and the library| λ (µm) | n | k |
|---|---|---|
| 0.254 | 1.656 | 0 |
| 0.405 | 1.618 | 7.207129e-08 |
| 0.436 | 1.617 | 8.654184e-08 |
| 0.547 | 1.606 | 1.383557e-07 |
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
- —
Lanthanum Fluoride is not often used as an optical material. Lanthanum Fluoride is usually doped with Europium at a nominal level of 0.3% mole. In this form, the usual application is as the active element in an ion-selective electrode for the detection and measurement of Fluoride ions in solution.
Lanthanum Fluoride is grown as small ingots of about 10mm diameter as it is difficult to anneal. Doped with Europium, it is a pale yellow colour.
REFERENCES:
(1) Jones and Shand, J.Crys.Growth. 2 (1968) p3611
(2) Sher, Solomon, Lee, and Meuller. Phys.Rev. 144, p593 (1966)
(3) Electronic Processes in Ionic Crystals (OU Press, NY, 1940) p.41 Optical data are for ordinary ray (o).