Axis Log x Log y

Click the plot to set the calculator wavelength. Note: k data cover 1820-4980 nm only; k = 0 elsewhere in the n range 1440-4970 nm.

At one wavelength

Refractive index n: 1.66811
Extinction coefficient k: 0.000843981

Permittivity ε₁: 2.78259
Permittivity ε₂: 0.00281571

Absorption coefficient α: 39.5738 cm⁻¹
Penetration depth δ = λ/(2πk): 505385 nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: -0.0255 µm⁻¹

Group index n_g: 1.73645
Group velocity dispersion: — fs²/mm

Dispersion parameter D: — ps/(nm·km)
Photon energy: 0.462628 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

# Kapton: Kawka and Buckius 2001: n 1.44–4.97 µm, k 1.82–4.98 µm
kapton = ls.fetch_refractiveindex("other", "Kapton", "Kawka", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(kapton.range_nm)  # (1440, 4970) nm
eps = kapton.eps([2680])  # 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_3b1e34b2cf5d/lightsmith"
kapton = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(kapton.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (kapton/kawka-buckius-2001).

# ... load kapton as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=kapton)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=1440, stop_nm=4970, 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"]).

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.

Comments and conditions

Fourier transform infrared (FTIR) spectroscopy is used to measure the bidirectional reflectivity of polyimide films on gold substrates in the infrared. The optical constants of cured polyimide are determined in the infrared region using a Lorentz model to characterize the absorption bands.

Notes on the source data (kept exactly as published):

k data cover 1820-4980 nm only; k = 0 elsewhere in the n range 1440-4970 nm

References

P. A. Kawka and R. O. Buckius. Optical properties of polyimide films in the infrared. Int. J. Thermophys. 22, 517–534 (2001)

doi:10.1023/a:1010797620483 Optical Properties of Polyimide Films in the Infrared, International Journal of Thermophysics (2001)

Cite

P. A. Kawka and R. O. Buckius. Optical Properties of Polyimide Films in the Infrared. International Journal of Thermophysics, 22, 517-534 (2001), doi:10.1023/a:1010797620483; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 354 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

Kapton, Kawka and Buckius 2001: n 1.44–4.97 µm, k 1.82–4.98 µm: n and k versus wavelength
λ (µm)	n	k
1.44	1.67569	0
1.45	1.67564	0
1.46	1.6756	0
1.47	1.67563	0
1.48	1.67558	0
1.49	1.67559	0
1.5	1.67555	0
1.51	1.67551	0
1.52	1.67552	0
1.53	1.67543	0
1.54	1.67546	0
1.55	1.67542	0
1.56	1.67541	0
1.57	1.67539	0
1.58	1.67534	0
1.59	1.67533	0
1.6	1.67525	0
1.61	1.67528	0
1.62	1.67523	0
1.63	1.67521	0
1.64	1.67518	0
1.65	1.67514	0
1.66	1.6751	0
1.67	1.67506	0
1.68	1.67504	0
1.69	1.67501	0
1.7	1.67499	0
1.71	1.67495	0
1.72	1.67492	0
1.73	1.67488	0
1.74	1.67487	0
1.75	1.67483	0
1.76	1.6748	0
1.77	1.67477	0
1.78	1.67474	0
1.79	1.67468	0
1.8	1.67464	0
1.81	1.67462	0
1.82	1.67458	2.062820e-05
1.83	1.67455	1.747850e-05
1.84	1.6745	1.837660e-05
1.85	1.67446	2.039460e-05
1.86	1.67442	2.051500e-05
1.87	1.67438	2.063480e-05
1.88	1.67436	2.075300e-05
1.89	1.67433	1.814110e-05
1.9	1.67428	1.238320e-05
1.91	1.67424	1.013500e-05
1.92	1.67421	1.168180e-05
1.93	1.67417	1.326100e-05
1.94	1.67413	1.485090e-05
1.95	1.67408	1.205410e-05
1.96	1.67405	8.087870e-06
1.97	1.67403	8.502320e-06
1.98	1.67396	9.760780e-06
1.99	1.67391	7.908470e-06
2	1.67386	5.314530e-06
2.01	1.6738	6.940480e-06
2.02	1.67376	9.634810e-06
2.03	1.67372	1.298050e-05
2.04	1.67367	1.653930e-05
2.05	1.67363	2.475160e-05
2.06	1.67358	3.501820e-05
2.07	1.67354	4.071300e-05
2.08	1.67351	4.080950e-05
2.09	1.67346	3.891490e-05
2.1	1.6734	3.047250e-05
2.11	1.67332	2.275080e-05
2.12	1.67325	2.461600e-05
2.13	1.6732	2.648110e-05
2.14	1.67317	2.821280e-05
2.15	1.67315	2.988110e-05
2.16	1.6731	3.256140e-05
2.17	1.67304	3.772120e-05
2.18	1.67298	4.288090e-05
2.19	1.67294	4.677890e-05
2.2	1.67289	5.062760e-05
2.21	1.67282	5.099530e-05
2.22	1.67275	4.218880e-05
2.23	1.67272	3.338240e-05
2.24	1.67266	3.445190e-05
2.25	1.67259	3.702210e-05
2.26	1.67253	3.885870e-05
2.27	1.67247	3.907510e-05
2.28	1.67241	3.929160e-05
2.29	1.67235	4.509690e-05
2.3	1.6723	5.419280e-05
2.31	1.67224	6.328880e-05
2.32	1.67218	7.144420e-05
2.33	1.67211	7.928090e-05
2.34	1.67205	8.622740e-05
2.35	1.67198	8.751730e-05
2.36	1.6719	8.880710e-05
2.37	1.67183	9.099130e-05
2.38	1.67177	9.642160e-05
2.39	1.6717	0.000101852
2.4	1.6716	0.000106556
2.41	1.67152	0.000109903
2.42	1.67144	0.00011325
2.43	1.67136	0.000117789
2.44	1.67129	0.000124419
2.45	1.67122	0.000131049
2.46	1.67115	0.000138127
2.47	1.67108	0.00014587
2.48	1.67097	0.000153612
2.49	1.67087	0.000162095
2.5	1.67075	0.000173592
2.51	1.67064	0.000185089
2.52	1.67055	0.000196586
2.53	1.67045	0.000208807
2.54	1.67036	0.000221035
2.55	1.67026	0.000233263
2.56	1.67016	0.000257487
2.57	1.67004	0.000283816
2.58	1.66992	0.000310383
2.59	1.66978	0.00033941
2.6	1.66963	0.000368437
2.61	1.66949	0.000397464
2.62	1.66934	0.000435239
2.63	1.66918	0.00047408
2.64	1.66901	0.00051292
2.65	1.66884	0.000593203
2.66	1.66861	0.00068097
2.67	1.66836	0.000760231
2.68	1.66811	0.000843981
2.69	1.66785	0.00102565
2.7	1.66758	0.00125928
2.71	1.66733	0.00158511
2.72	1.66707	0.00199914
2.73	1.66687	0.00271038
2.74	1.667	0.00361881
2.75	1.66712	0.00438871
2.76	1.66836	0.00456467
2.77	1.66975	0.00406124
2.78	1.66972	0.00308552
2.79	1.66969	0.00295696
2.8	1.66953	0.00288409
2.81	1.66936	0.00284434
2.82	1.66923	0.00289993
2.83	1.66932	0.00297312
2.84	1.66941	0.00314599
2.85	1.66949	0.00331885
2.86	1.66958	0.00353525
2.87	1.66984	0.00353522
2.88	1.6701	0.00353165
2.89	1.67036	0.00339178
2.9	1.67054	0.00322472
2.91	1.67056	0.00303604
2.92	1.67057	0.00278579
2.93	1.67055	0.00255043
2.94	1.67048	0.00227124
2.95	1.67041	0.00208929
2.96	1.6703	0.00192569
2.97	1.67015	0.00173293
2.98	1.66999	0.00156294
2.99	1.66982	0.00144039
3	1.66962	0.00134829
3.01	1.66942	0.00126758
3.02	1.66921	0.00118964
3.03	1.66901	0.00113532
3.04	1.66881	0.00110736
3.05	1.66861	0.00107939
3.06	1.66839	0.00105142
3.07	1.66816	0.00102395
3.08	1.66794	0.00102951
3.09	1.66771	0.00103508
3.1	1.66749	0.00104065
3.11	1.66726	0.00104621
3.12	1.66703	0.00107012
3.13	1.66678	0.00111604
3.14	1.66652	0.00116197
3.15	1.66627	0.00121472
3.16	1.66596	0.00132585
3.17	1.66562	0.0014532
3.18	1.66529	0.00159613
3.19	1.66496	0.00184888
3.2	1.66462	0.00207845
3.21	1.66427	0.00248408
3.22	1.66393	0.0030182
3.23	1.66396	0.00346036
3.24	1.66408	0.00429045
3.25	1.6642	0.00494931
3.26	1.66455	0.00516577
3.27	1.66523	0.00524204
3.28	1.66566	0.00479227
3.29	1.66594	0.00438257
3.3	1.66622	0.00431045
3.31	1.66618	0.0040816
3.32	1.66578	0.00392998
3.33	1.66538	0.00386909
3.34	1.66513	0.00408567
3.35	1.66496	0.00437012
3.36	1.66479	0.00469417
3.37	1.66466	0.00526209
3.38	1.66469	0.00575919
3.39	1.66473	0.00634003
3.4	1.66476	0.00688821
3.41	1.66503	0.00759601
3.42	1.66554	0.00782586
3.43	1.66689	0.00793598
3.44	1.66786	0.00804493
3.45	1.66843	0.00772326
3.46	1.66901	0.00739004
3.47	1.66968	0.00646776
3.48	1.67043	0.0057576
3.49	1.67041	0.00523652
3.5	1.6703	0.0045463
3.51	1.67019	0.00410377
3.52	1.67007	0.00360529
3.53	1.66987	0.00323617
3.54	1.66964	0.00287135
3.55	1.66941	0.00258696
3.56	1.66918	0.00230566
3.57	1.66894	0.00210619
3.58	1.66867	0.00191359
3.59	1.6684	0.00174804
3.6	1.66813	0.00162181
3.61	1.66786	0.00150104
3.62	1.66758	0.00138412
3.63	1.6673	0.00128337
3.64	1.66701	0.00120389
3.65	1.66673	0.0011244
3.66	1.6665	0.00107046
3.67	1.66628	0.0010196
3.68	1.66605	0.000968741
3.69	1.66583	0.000926014
3.7	1.66561	0.000889637
3.71	1.66541	0.000853259
3.72	1.6652	0.000816881
3.73	1.665	0.000781074
3.74	1.66479	0.00075833
3.75	1.66458	0.000735585
3.76	1.66436	0.000712841
3.77	1.66414	0.000690097
3.78	1.66393	0.000667352
3.79	1.66371	0.000644608
3.8	1.6635	0.000627086
3.81	1.66329	0.000613727
3.82	1.66308	0.000600368
3.83	1.66287	0.000587008
3.84	1.66266	0.000573649
3.85	1.66245	0.000560289
3.86	1.66224	0.00054693
3.87	1.66203	0.000535356
3.88	1.66182	0.000529057
3.89	1.66161	0.000522759
3.9	1.66141	0.00051646
3.91	1.66121	0.000510162
3.92	1.661	0.000503863
3.93	1.6608	0.000497565
3.94	1.6606	0.000491266
3.95	1.66039	0.000488791
3.96	1.66017	0.000488889
3.97	1.65995	0.000488987
3.98	1.65972	0.000489086
3.99	1.6595	0.000489184
4	1.65927	0.000489283
4.01	1.65907	0.000489381
4.02	1.65886	0.00048948
4.03	1.65865	0.000488789
4.04	1.65845	0.000487882
4.05	1.65824	0.000486975
4.06	1.658	0.000486068
4.07	1.65775	0.000485161
4.08	1.65751	0.000484254
4.09	1.65727	0.000483347
4.1	1.65702	0.00048244
4.11	1.65676	0.000481533
4.12	1.6565	0.000481398
4.13	1.65625	0.000483879
4.14	1.65599	0.000486359
4.15	1.65573	0.00048884
4.16	1.65549	0.00049132
4.17	1.65526	0.0004938
4.18	1.65503	0.000496281
4.19	1.6548	0.000498761
4.2	1.65456	0.000501242
4.21	1.65431	0.000504906
4.22	1.65401	0.000509897
4.23	1.65371	0.000514887
4.24	1.65341	0.000519878
4.25	1.65312	0.000524869
4.26	1.65282	0.00052986
4.27	1.65258	0.00053485
4.28	1.65233	0.000539841
4.29	1.65208	0.000544832
4.3	1.65183	0.00054991
4.31	1.65158	0.000555055
4.32	1.65131	0.0005602
4.33	1.65104	0.000565345
4.34	1.65076	0.000570491
4.35	1.65049	0.000575636
4.36	1.65022	0.000580781
4.37	1.64994	0.000585926
4.38	1.6496	0.000591071
4.39	1.64926	0.000606433
4.4	1.64893	0.00062672
4.41	1.64859	0.000647006
4.42	1.64825	0.000667292
4.43	1.64792	0.000687579
4.44	1.64759	0.000696996
4.45	1.64726	0.000705154
4.46	1.64696	0.000713312
4.47	1.64666	0.00072147
4.48	1.64636	0.000729627
4.49	1.646	0.000737785
4.5	1.64561	0.000745943
4.51	1.64521	0.0007541
4.52	1.64466	0.000763083
4.53	1.64398	0.000781265
4.54	1.64345	0.000799448
4.55	1.64305	0.00081763
4.56	1.64265	0.000835812
4.57	1.64225	0.000853995
4.58	1.64177	0.000872177
4.59	1.64124	0.00089036
4.6	1.64071	0.000908542
4.61	1.64026	0.000924259
4.62	1.63981	0.000939314
4.63	1.63937	0.00095437
4.64	1.63889	0.000969425
4.65	1.63834	0.00098448
4.66	1.63779	0.000999535
4.67	1.63729	0.00101459
4.68	1.63682	0.00102965
4.69	1.63636	0.00104817
4.7	1.63588	0.00107527
4.71	1.63529	0.00110237
4.72	1.6347	0.00112947
4.73	1.63411	0.00115657
4.74	1.63353	0.00118367
4.75	1.63296	0.00121194
4.76	1.63239	0.00124052
4.77	1.63184	0.00126909
4.78	1.63141	0.00129767
4.79	1.63097	0.00132625
4.8	1.63054	0.00135482
4.81	1.6301	0.00138364
4.82	1.6296	0.00141461
4.83	1.62879	0.00144559
4.84	1.62799	0.00147656
4.85	1.62701	0.00150753
4.86	1.62577	0.00153851
4.87	1.62482	0.00156948
4.88	1.62424	0.00160765
4.89	1.62371	0.00165084
4.9	1.62315	0.00169403
4.91	1.62246	0.00173723
4.92	1.62168	0.00179064
4.93	1.62061	0.00184955
4.94	1.61937	0.00190847
4.95	1.61831	0.00196479
4.96	1.61762	0.00201822
4.97	1.61693	0.00207165

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