Optical constants

Refractive index of CaF₂ (Calcium fluoride)

Malitson 1963: n 0.23–9.7 µm; 24 °C

Data: formula 1
Range: 0.23–9.7 µm
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.43385
Extinction coefficient k: 0

Permittivity ε₁: 2.05592
Permittivity ε₂: 0

Absorption coefficient α: 0 cm⁻¹
Penetration depth δ = λ/(2πk): — nm

Abbe number V_d: 94.996
Chromatic dispersion dn/dλ: -0.0236339 µm⁻¹

Group index n_g: 1.44774
Group velocity dispersion: 41.359 fs²/mm

Dispersion parameter D: -225.635 ps/(nm·km)
Photon energy: 2.11001 eV

ε = (n + ik)², α = 4πk/λ, n_g = 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

# CaF2 (Calcium fluoride): Malitson 1963: n 0.23–9.7 µm; 24 °C
caf2 = ls.fetch_refractiveindex("main", "CaF2", "Malitson", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(caf2.range_nm)  # (230, 9700) nm
eps = caf2.eps([633])  # complex permittivity

Downloads 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_c4521f50116d/lightsmith"
caf2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(caf2.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (caf2/malitson-1963).

# ... load caf2 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=caf2)],
    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 wavelength

Same spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_c4521f50116d/lightsmith?model=drude_lorentz"
caf2_dl = ls.DrudeLorentz.model_validate(json.load(urllib.request.urlopen(url)))

A dispersive Drude–Lorentz model for time-domain solvers.

Materials guide Open a sphere of it in Studio Quick start Ask the community

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.

Dispersion formula

Sellmeier (formula 1), λ in µm

n^{2} - 1 = \frac{0.5675888 λ^{2}}{λ^{2} - {0.050263605}^{2}} + \frac{0.4710914 λ^{2}}{λ^{2} - {0.1003909}^{2}} + \frac{3.8484723 λ^{2}}{λ^{2} - {34.64904}^{2}}

Valid from 0.23 to 9.7 µm.

Coefficients as stored

C_i	Value
C1	0.0
C2	0.5675888
C3	0.050263605
C4	0.4710914
C5	0.1003909
C6	3.8484723
C7	34.64904

Comments and conditions

24 °C

References

I. H. Malitson. A redetermination of some optical properties of calcium fluoride. Appl. Opt. 2, 1103-1107 (1963)

doi:10.1364/ao.2.001103 A Redetermination of Some Optical Properties of Calcium Fluoride, Applied Optics (1963)

Cite

Irving H. Malitson. A Redetermination of Some Optical Properties of Calcium Fluoride. Applied Optics, 2, 1103 (1963), doi:10.1364/ao.2.001103; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 400 wavelengths, the same grid as the API and the library

CSV comma separated TXT tab separated YAML n, k Full database record original YAML All quantities CSV JSON metadata

CaF2 (Calcium fluoride), Malitson 1963: n 0.23–9.7 µm; 24 °C: n and k versus wavelength
λ (µm)	n
0.23	1.475755
0.232167	1.474707
0.234355	1.473685
0.236563	1.472689
0.238792	1.471717
0.241041	1.470769
0.243313	1.469845
0.245605	1.468943
0.247919	1.468063
0.250255	1.467204
0.252613	1.466366
0.254993	1.465548
0.257396	1.464749
0.259821	1.463969
0.262269	1.463207
0.26474	1.462463
0.267234	1.461737
0.269752	1.461027
0.272294	1.460333
0.27486	1.459656
0.277449	1.458994
0.280063	1.458347
0.282702	1.457714
0.285366	1.457096
0.288055	1.456492
0.290769	1.455901
0.293508	1.455324
0.296274	1.454759
0.299065	1.454207
0.301883	1.453667
0.304727	1.453138
0.307599	1.452622
0.310497	1.452116
0.313422	1.451622
0.316375	1.451138
0.319356	1.450665
0.322365	1.450201
0.325403	1.449748
0.328469	1.449304
0.331563	1.44887
0.334688	1.448445
0.337841	1.448029
0.341024	1.447622
0.344237	1.447223
0.347481	1.446833
0.350755	1.446451
0.35406	1.446077
0.357395	1.44571
0.360763	1.445351
0.364162	1.445
0.367593	1.444656
0.371057	1.444318
0.374553	1.443988
0.378082	1.443665
0.381644	1.443348
0.38524	1.443037
0.38887	1.442733
0.392534	1.442435
0.396232	1.442143
0.399966	1.441856
0.403734	1.441576
0.407538	1.441301
0.411378	1.441031
0.415254	1.440767
0.419166	1.440508
0.423116	1.440254
0.427102	1.440006
0.431127	1.439762
0.435189	1.439523
0.439289	1.439288
0.443428	1.439058
0.447606	1.438833
0.451824	1.438611
0.456081	1.438395
0.460378	1.438182
0.464716	1.437973
0.469094	1.437769
0.473514	1.437568
0.477975	1.437371
0.482479	1.437178
0.487025	1.436988
0.491614	1.436802
0.496246	1.43662
0.500921	1.436441
0.505641	1.436265
0.510405	1.436092
0.515214	1.435923
0.520069	1.435757
0.524969	1.435594
0.529915	1.435434
0.534908	1.435276
0.539948	1.435122
0.545035	1.43497
0.550171	1.434822
0.555354	1.434675
0.560587	1.434532
0.565869	1.434391
0.571201	1.434252
0.576582	1.434116
0.582015	1.433982
0.587499	1.433851
0.593034	1.433722
0.598622	1.433595
0.604262	1.43347
0.609956	1.433347
0.615703	1.433227
0.621504	1.433108
0.62736	1.432992
0.633271	1.432877
0.639237	1.432764
0.64526	1.432654
0.65134	1.432544
0.657477	1.432437
0.663672	1.432332
0.669925	1.432228
0.676237	1.432125
0.682608	1.432025
0.68904	1.431926
0.695532	1.431828
0.702086	1.431732
0.708701	1.431637
0.715378	1.431544
0.722118	1.431452
0.728922	1.431362
0.73579	1.431273
0.742723	1.431185
0.749721	1.431098
0.756785	1.431012
0.763915	1.430928
0.771113	1.430845
0.778378	1.430763
0.785712	1.430682
0.793115	1.430602
0.800588	1.430523
0.808131	1.430445
0.815746	1.430368
0.823432	1.430292
0.83119	1.430217
0.839022	1.430143
0.846927	1.43007
0.854907	1.429997
0.862962	1.429925
0.871092	1.429854
0.8793	1.429784
0.887585	1.429715
0.895948	1.429646
0.904389	1.429578
0.912911	1.42951
0.921512	1.429443
0.930195	1.429377
0.938959	1.429311
0.947806	1.429246
0.956736	1.429181
0.965751	1.429117
0.97485	1.429053
0.984035	1.42899
0.993307	1.428927
1.00267	1.428865
1.01211	1.428803
1.02165	1.428741
1.03128	1.42868
1.04099	1.428619
1.0508	1.428558
1.0607	1.428498
1.07069	1.428438
1.08078	1.428378
1.09097	1.428318
1.10125	1.428258
1.11162	1.428199
1.1221	1.428139
1.13267	1.42808
1.14334	1.428021
1.15411	1.427962
1.16499	1.427903
1.17596	1.427844
1.18704	1.427785
1.19823	1.427727
1.20952	1.427668
1.22091	1.427609
1.23242	1.42755
1.24403	1.42749
1.25575	1.427431
1.26758	1.427372
1.27952	1.427312
1.29158	1.427252
1.30375	1.427193
1.31603	1.427132
1.32843	1.427072
1.34095	1.427011
1.35358	1.42695
1.36634	1.426889
1.37921	1.426828
1.39221	1.426766
1.40532	1.426703
1.41857	1.426641
1.43193	1.426577
1.44542	1.426514
1.45904	1.42645
1.47279	1.426385
1.48667	1.42632
1.50067	1.426255
1.51481	1.426189
1.52909	1.426122
1.54349	1.426055
1.55804	1.425987
1.57272	1.425918
1.58753	1.425849
1.60249	1.425779
1.61759	1.425708
1.63283	1.425637
1.64822	1.425565
1.66375	1.425492
1.67942	1.425418
1.69525	1.425343
1.71122	1.425268
1.72734	1.425191
1.74362	1.425114
1.76004	1.425035
1.77663	1.424956
1.79337	1.424875
1.81026	1.424794
1.82732	1.424711
1.84454	1.424628
1.86192	1.424543
1.87946	1.424457
1.89717	1.42437
1.91504	1.424281
1.93309	1.424192
1.9513	1.424101
1.96969	1.424008
1.98825	1.423915
2.00698	1.42382
2.02589	1.423723
2.04498	1.423625
2.06424	1.423526
2.08369	1.423425
2.10333	1.423322
2.12314	1.423218
2.14315	1.423112
2.16334	1.423005
2.18372	1.422895
2.2043	1.422784
2.22507	1.422672
2.24603	1.422557
2.2672	1.42244
2.28856	1.422322
2.31012	1.422201
2.33189	1.422079
2.35386	1.421954
2.37604	1.421828
2.39842	1.421699
2.42102	1.421568
2.44383	1.421435
2.46686	1.421299
2.4901	1.421161
2.51356	1.421021
2.53725	1.420878
2.56115	1.420733
2.58528	1.420585
2.60964	1.420434
2.63423	1.420281
2.65905	1.420125
2.6841	1.419967
2.70939	1.419805
2.73492	1.419641
2.76069	1.419474
2.7867	1.419303
2.81296	1.41913
2.83946	1.418953
2.86622	1.418773
2.89322	1.41859
2.92048	1.418404
2.948	1.418214
2.97577	1.41802
3.00381	1.417823
3.03211	1.417623
3.06068	1.417419
3.08952	1.41721
3.11863	1.416999
3.14801	1.416783
3.17768	1.416563
3.20762	1.416339
3.23784	1.41611
3.26835	1.415878
3.29914	1.415641
3.33022	1.415399
3.3616	1.415153
3.39328	1.414903
3.42525	1.414647
3.45752	1.414387
3.4901	1.414122
3.52298	1.413852
3.55617	1.413577
3.58968	1.413296
3.6235	1.41301
3.65764	1.412719
3.69211	1.412422
3.72689	1.412119
3.76201	1.41181
3.79745	1.411496
3.83323	1.411175
3.86935	1.410849
3.90581	1.410516
3.94261	1.410176
3.97976	1.40983
4.01725	1.409477
4.0551	1.409118
4.09331	1.408751
4.13188	1.408377
4.17081	1.407996
4.21011	1.407607
4.24978	1.407211
4.28982	1.406807
4.33024	1.406396
4.37104	1.405976
4.41222	1.405548
4.45379	1.405111
4.49576	1.404666
4.53812	1.404212
4.58087	1.403749
4.62404	1.403277
4.6676	1.402795
4.71158	1.402304
4.75598	1.401804
4.80079	1.401293
4.84602	1.400772
4.89168	1.400241
4.93777	1.399699
4.98429	1.399146
5.03125	1.398582
5.07866	1.398007
5.12651	1.39742
5.17481	1.396822
5.22357	1.396211
5.27279	1.395589
5.32247	1.394953
5.37262	1.394305
5.42324	1.393643
5.47434	1.392969
5.52592	1.39228
5.57798	1.391577
5.63054	1.39086
5.68359	1.390129
5.73714	1.389382
5.7912	1.38862
5.84576	1.387843
5.90084	1.387049
5.95644	1.38624
6.01256	1.385413
6.06921	1.384569
6.12639	1.383708
6.18412	1.382829
6.24238	1.381932
6.3012	1.381016
6.36057	1.380081
6.4205	1.379126
6.481	1.378151
6.54206	1.377156
6.6037	1.37614
6.66592	1.375102
6.72873	1.374043
6.79212	1.372961
6.85612	1.371856
6.92072	1.370728
6.98593	1.369575
7.05175	1.368398
7.11819	1.367195
7.18526	1.365967
7.25296	1.364712
7.3213	1.36343
7.39028	1.362121
7.45991	1.360783
7.5302	1.359415
7.60115	1.358018
7.67277	1.35659
7.74506	1.355131
7.81803	1.35364
7.8917	1.352116
7.96605	1.350558
8.04111	1.348965
8.11687	1.347337
8.19335	1.345672
8.27055	1.34397
8.34847	1.34223
8.42713	1.34045
8.50653	1.33863
8.58668	1.336768
8.66759	1.334864
8.74925	1.332916
8.83169	1.330923
8.9149	1.328884
8.9989	1.326798
9.08369	1.324663
9.16927	1.322478
9.25567	1.320242
9.34288	1.317953
9.4309	1.315609
9.51976	1.31321
9.60946	1.310753
9.7	1.308237

Optical transmission calculator

Free-standing sample in vacuum, normal incidence

Transmittance T: —
Reflectance R: —

Fresnel reflection calculator

R_p: —
R_s: —
R = (R_p+R_s)/2: —
Phase φ_p: —
Phase φ_s: —
Brewster angle θ_B: —
Critical angle θ_C: —

CaF₂ (Calcium fluoride): all datasets

About CaF2 (Calcium fluoride)

Calcium fluoride (CaF₂) is an inorganic compound with a cubic crystal structure, exhibiting excellent optical transparency over a wide range of wavelengths, from ultraviolet to infrared. It has a low refractive index (approximately 1.43 at 589 nm) and minimal chromatic dispersion, making it a preferred material for lenses, optical windows, and other components in spectroscopy and high-resolution imaging systems. Due to its low solubility and chemical stability, it is highly resistant to weathering and corrosion, making it suitable for harsh environments. In the realm of laser applications, CaF₂ is often used as an optical gain medium when doped with rare-earth ions such as ytterbium or erbium. The compound is synthesized through various methods, including precipitation from aqueous solutions and high-temperature reactions between calcium and fluorine gas. Its excellent optical, thermal, and chemical properties make calcium fluoride a material of considerable interest for a wide variety of optical and industrial applications. Mineral: Fluorite (fluorspar)

More about CaF2 (Calcium fluoride) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/CaF2/nk/Malitson.yml
ID: ds_c4521f50116d
API: /v1/datasets/ds_c4521f50116d

Plot