Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.38956
Extinction coefficient k: 0

Permittivity ε₁: 1.93087
Permittivity ε₂: 0

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

Abbe number V_d: 104.86
Chromatic dispersion dn/dλ: -0.0193579 µm⁻¹

Group index n_g: 1.40093
Group velocity dispersion: 31.7895 fs²/mm

Dispersion parameter D: -173.429 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

# MgF2 (Magnesium fluoride): Dodge 1984: n(e) 0.2–7.0 µm
mgf2 = ls.fetch_refractiveindex("main", "MgF2", "Dodge-e", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(mgf2.range_nm)  # (200, 7000) nm
eps = mgf2.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_38a6d377b79a/lightsmith"
mgf2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(mgf2.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (mgf2/dodge-1984-e).

# ... load mgf2 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=mgf2)],
    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_38a6d377b79a/lightsmith?model=drude_lorentz"
mgf2_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{0.41344023 λ^{2}}{λ^{2} - {0.03684262}^{2}} + \frac{0.50497499 λ^{2}}{λ^{2} - {0.09076162}^{2}} + \frac{2.4904862 λ^{2}}{λ^{2} - {23.771995}^{2}}

Valid from 0.2 to 7.0 µm.

Coefficients as stored

C_i	Value
C1	0.0
C2	0.41344023
C3	0.03684262
C4	0.50497499
C5	0.09076162
C6	2.4904862
C7	23.771995

Comments and conditions

19 °C. Extraordinary ray (e).

Conditions

temperature: 292 K
direction: e

References

M. J. Dodge. Refractive properties of magnesium fluoride. Appl. Opt. 23, 1980-1985 (1984)

doi:10.1364/ao.23.001980 Refractive properties of magnesium fluoride, Applied Optics (1984)

Cite

Marilyn J. Dodge. Refractive properties of magnesium fluoride. Applied Optics, 23, 1980 (1984), doi:10.1364/ao.23.001980; 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

MgF2 (Magnesium fluoride), Dodge 1984: n(e) 0.2–7.0 µm: n and k versus wavelength
λ (µm)	n
0.2	1.436568
0.20179	1.435465
0.203596	1.43439
0.205418	1.433341
0.207257	1.432318
0.209112	1.43132
0.210984	1.430347
0.212872	1.429397
0.214777	1.428471
0.2167	1.427566
0.218639	1.426683
0.220596	1.425821
0.222571	1.424979
0.224563	1.424158
0.226573	1.423355
0.228601	1.422571
0.230647	1.421805
0.232711	1.421056
0.234794	1.420325
0.236896	1.41961
0.239016	1.418911
0.241155	1.418228
0.243314	1.417561
0.245491	1.416908
0.247689	1.41627
0.249906	1.415646
0.252142	1.415036
0.254399	1.414439
0.256676	1.413855
0.258974	1.413283
0.261292	1.412724
0.26363	1.412177
0.26599	1.411642
0.268371	1.411119
0.270773	1.410606
0.273196	1.410104
0.275641	1.409613
0.278108	1.409132
0.280598	1.408662
0.283109	1.408201
0.285643	1.407749
0.2882	1.407308
0.290779	1.406875
0.293382	1.406451
0.296008	1.406036
0.298657	1.405629
0.30133	1.405231
0.304027	1.40484
0.306749	1.404458
0.309494	1.404083
0.312264	1.403716
0.315059	1.403357
0.317879	1.403004
0.320724	1.402659
0.323595	1.40232
0.326491	1.401988
0.329413	1.401663
0.332362	1.401344
0.335337	1.401031
0.338338	1.400724
0.341366	1.400424
0.344422	1.400129
0.347504	1.39984
0.350615	1.399557
0.353753	1.399279
0.356919	1.399006
0.360114	1.398739
0.363337	1.398476
0.366589	1.398219
0.36987	1.397967
0.373181	1.397719
0.376521	1.397476
0.379891	1.397238
0.383291	1.397004
0.386722	1.396775
0.390183	1.396549
0.393675	1.396328
0.397199	1.396111
0.400754	1.395899
0.404341	1.39569
0.40796	1.395484
0.411611	1.395283
0.415296	1.395085
0.419013	1.394891
0.422763	1.394701
0.426547	1.394514
0.430365	1.39433
0.434217	1.39415
0.438103	1.393972
0.442024	1.393798
0.445981	1.393627
0.449972	1.393459
0.454	1.393294
0.458063	1.393132
0.462163	1.392973
0.4663	1.392817
0.470473	1.392663
0.474684	1.392512
0.478933	1.392363
0.48322	1.392218
0.487545	1.392074
0.491908	1.391933
0.496311	1.391794
0.500754	1.391658
0.505235	1.391524
0.509758	1.391392
0.51432	1.391263
0.518924	1.391135
0.523568	1.39101
0.528254	1.390887
0.532982	1.390765
0.537753	1.390646
0.542566	1.390529
0.547422	1.390413
0.552322	1.390299
0.557265	1.390187
0.562253	1.390077
0.567286	1.389969
0.572363	1.389862
0.577486	1.389757
0.582655	1.389653
0.58787	1.389551
0.593132	1.389451
0.59844	1.389352
0.603797	1.389254
0.609201	1.389158
0.614654	1.389063
0.620155	1.38897
0.625706	1.388877
0.631306	1.388787
0.636957	1.388697
0.642658	1.388609
0.64841	1.388521
0.654213	1.388435
0.660069	1.388351
0.665977	1.388267
0.671937	1.388184
0.677952	1.388102
0.68402	1.388022
0.690142	1.387942
0.696319	1.387863
0.702551	1.387786
0.70884	1.387709
0.715184	1.387633
0.721585	1.387558
0.728044	1.387483
0.73456	1.38741
0.741135	1.387337
0.747768	1.387265
0.754461	1.387194
0.761214	1.387124
0.768027	1.387054
0.774901	1.386985
0.781837	1.386916
0.788835	1.386848
0.795895	1.386781
0.803019	1.386714
0.810206	1.386648
0.817458	1.386582
0.824775	1.386517
0.832157	1.386453
0.839605	1.386388
0.84712	1.386325
0.854702	1.386261
0.862352	1.386198
0.87007	1.386136
0.877858	1.386074
0.885715	1.386012
0.893643	1.38595
0.901641	1.385889
0.909711	1.385828
0.917854	1.385767
0.926069	1.385707
0.934358	1.385646
0.942721	1.385586
0.951158	1.385526
0.959672	1.385467
0.968261	1.385407
0.976928	1.385347
0.985672	1.385288
0.994494	1.385229
1.00339	1.385169
1.01238	1.38511
1.02144	1.385051
1.03058	1.384992
1.0398	1.384932
1.04911	1.384873
1.0585	1.384814
1.06797	1.384754
1.07753	1.384695
1.08718	1.384635
1.09691	1.384575
1.10673	1.384516
1.11663	1.384455
1.12663	1.384395
1.13671	1.384335
1.14688	1.384274
1.15715	1.384213
1.16751	1.384152
1.17796	1.38409
1.1885	1.384028
1.19914	1.383966
1.20987	1.383904
1.2207	1.383841
1.23162	1.383777
1.24265	1.383714
1.25377	1.383649
1.26499	1.383585
1.27631	1.38352
1.28774	1.383454
1.29926	1.383388
1.31089	1.383321
1.32263	1.383254
1.33446	1.383186
1.34641	1.383118
1.35846	1.383049
1.37062	1.382979
1.38289	1.382909
1.39526	1.382838
1.40775	1.382766
1.42035	1.382693
1.43306	1.38262
1.44589	1.382546
1.45883	1.382471
1.47189	1.382395
1.48506	1.382319
1.49836	1.382241
1.51177	1.382163
1.5253	1.382084
1.53895	1.382003
1.55272	1.381922
1.56662	1.38184
1.58064	1.381756
1.59479	1.381672
1.60907	1.381586
1.62347	1.3815
1.638	1.381412
1.65266	1.381323
1.66745	1.381233
1.68238	1.381141
1.69743	1.381048
1.71263	1.380954
1.72795	1.380859
1.74342	1.380762
1.75903	1.380664
1.77477	1.380564
1.79065	1.380463
1.80668	1.380361
1.82285	1.380257
1.83917	1.380151
1.85563	1.380044
1.87224	1.379935
1.889	1.379824
1.9059	1.379712
1.92296	1.379598
1.94017	1.379482
1.95754	1.379365
1.97506	1.379245
1.99274	1.379124
2.01057	1.379
2.02857	1.378875
2.04672	1.378747
2.06504	1.378618
2.08353	1.378486
2.10218	1.378353
2.12099	1.378217
2.13997	1.378079
2.15913	1.377938
2.17845	1.377795
2.19795	1.37765
2.21762	1.377502
2.23747	1.377352
2.2575	1.3772
2.27771	1.377044
2.29809	1.376886
2.31866	1.376726
2.33941	1.376562
2.36035	1.376396
2.38148	1.376227
2.40279	1.376055
2.4243	1.37588
2.446	1.375702
2.46789	1.375521
2.48998	1.375336
2.51227	1.375149
2.53475	1.374958
2.55744	1.374764
2.58033	1.374566
2.60343	1.374365
2.62673	1.37416
2.65024	1.373952
2.67396	1.37374
2.69789	1.373524
2.72204	1.373304
2.7464	1.373081
2.77099	1.372853
2.79579	1.372621
2.82081	1.372385
2.84606	1.372145
2.87153	1.3719
2.89723	1.371651
2.92316	1.371398
2.94933	1.37114
2.97573	1.370877
3.00236	1.370609
3.02923	1.370336
3.05635	1.370059
3.0837	1.369776
3.1113	1.369488
3.13915	1.369195
3.16725	1.368896
3.19559	1.368592
3.2242	1.368283
3.25305	1.367967
3.28217	1.367646
3.31155	1.367318
3.34119	1.366985
3.37109	1.366645
3.40127	1.366299
3.43171	1.365947
3.46242	1.365588
3.49341	1.365222
3.52468	1.364849
3.55623	1.36447
3.58806	1.364083
3.62017	1.363689
3.65258	1.363287
3.68527	1.362878
3.71825	1.362461
3.75153	1.362036
3.78511	1.361603
3.81899	1.361161
3.85317	1.360712
3.88766	1.360253
3.92246	1.359786
3.95756	1.35931
3.99299	1.358825
4.02873	1.35833
4.06478	1.357826
4.10117	1.357312
4.13787	1.356788
4.17491	1.356255
4.21228	1.35571
4.24998	1.355155
4.28802	1.35459
4.3264	1.354013
4.36512	1.353425
4.40419	1.352825
4.44361	1.352214
4.48338	1.351591
4.52351	1.350955
4.564	1.350307
4.60485	1.349646
4.64606	1.348972
4.68765	1.348284
4.72961	1.347583
4.77194	1.346868
4.81465	1.346138
4.85774	1.345394
4.90122	1.344635
4.94509	1.343861
4.98935	1.343071
5.03401	1.342266
5.07906	1.341444
5.12452	1.340605
5.17039	1.339749
5.21667	1.338876
5.26336	1.337984
5.31047	1.337075
5.358	1.336147
5.40596	1.3352
5.45434	1.334233
5.50316	1.333246
5.55242	1.332239
5.60211	1.331211
5.65226	1.330161
5.70285	1.329089
5.75389	1.327995
5.80539	1.326878
5.85735	1.325737
5.90978	1.324572
5.96267	1.323382
6.01604	1.322167
6.06989	1.320926
6.12421	1.319658
6.17903	1.318363
6.23433	1.31704
6.29013	1.315689
6.34643	1.314308
6.40324	1.312896
6.46055	1.311454
6.51837	1.30998
6.57672	1.308474
6.63558	1.306934
6.69497	1.30536
6.7549	1.303751
6.81536	1.302105
6.87636	1.300423
6.9379	1.298703
7	1.296943

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: —

Plot