Optical constants

Refractive index of Al (Aluminium)

Cheng et al. 2016: n,k 0.225–1.00 µm

Data: tabulated nk
Range: 0.2254–0.9999 µm
Points: 427
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 0.69256
Extinction coefficient k: 5.63867

Permittivity ε₁: -31.315
Permittivity ε₂: 7.81023

Absorption coefficient α: 1.20588e+06 cm⁻¹
Penetration depth δ = λ/(2πk): 16.5854 nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: 2.98195 µm⁻¹

Group index n_g: -1.05963
Group velocity dispersion: — fs²/mm

Dispersion parameter D: — 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

# Al (Aluminium): Cheng et al. 2016: n,k 0.225–1.00 µm
al = ls.fetch_refractiveindex("main", "Al", "Cheng", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(al.range_nm)  # (225.43, 999.87) nm
eps = al.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_abd1b7306990/lightsmith"
al = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(al.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (al/cheng-2016).

# ... load al as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=al)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=999, 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

Epitaxially grown Al film, dielectric constants for room temperature

References

F. Cheng, P.-H. Su, J. Choi, S. Gwo, X. Li, C.-K. Shih. Epitaxial growth of atomically smooth aluminum on silicon and its intrinsic optical properties. ACS Nano 10, 9852-9860 (2016) (See supporting information)

doi:10.1021/acsnano.6b05556 Epitaxial Growth of Atomically Smooth Aluminum on Silicon and Its Intrinsic Optical Properties, ACS Nano (2016)

Cite

Fei Cheng et al.. Epitaxial Growth of Atomically Smooth Aluminum on Silicon and Its Intrinsic Optical Properties. ACS Nano, 10, 9852-9860 (2016), doi:10.1021/acsnano.6b05556; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

427 rows as published

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

Al (Aluminium), Cheng et al. 2016: n,k 0.225–1.00 µm: n and k versus wavelength
λ (µm)	n	k
0.22543	0.12397	1.99044
0.22584	0.12431	1.99503
0.22625	0.12466	1.99963
0.22666	0.125	2.00423
0.22708	0.12534	2.00883
0.22749	0.12569	2.01343
0.22791	0.12603	2.01806
0.22833	0.12638	2.02269
0.22875	0.12673	2.02733
0.22918	0.12708	2.03198
0.2296	0.12743	2.03667
0.23003	0.12778	2.04133
0.23045	0.12814	2.04605
0.23088	0.12849	2.05078
0.23131	0.12885	2.05553
0.23175	0.12922	2.06027
0.23218	0.12958	2.06504
0.23262	0.12995	2.06983
0.23305	0.13031	2.0746
0.23349	0.13068	2.07942
0.23393	0.13105	2.08427
0.23437	0.13143	2.08911
0.23482	0.1318	2.09396
0.23526	0.13218	2.09885
0.23571	0.13256	2.10373
0.23616	0.13294	2.10864
0.23661	0.13332	2.11355
0.23706	0.13371	2.11851
0.23752	0.1341	2.12346
0.23797	0.13448	2.12842
0.23843	0.13488	2.13342
0.23889	0.13527	2.13843
0.23935	0.13567	2.14346
0.23981	0.13607	2.14849
0.24028	0.13647	2.15354
0.24075	0.13687	2.15862
0.24121	0.13728	2.16369
0.24168	0.13769	2.16881
0.24216	0.1381	2.17393
0.24263	0.13851	2.17908
0.24311	0.13892	2.18424
0.24358	0.13934	2.18941
0.24406	0.13976	2.19461
0.24454	0.14018	2.19981
0.24503	0.14061	2.20506
0.24551	0.14103	2.21029
0.246	0.14146	2.21554
0.24649	0.14189	2.22084
0.24698	0.14233	2.22615
0.24747	0.14276	2.23148
0.24797	0.1432	2.23681
0.24847	0.14364	2.24217
0.24896	0.14409	2.24755
0.24947	0.14453	2.25295
0.24997	0.14498	2.25839
0.25047	0.14544	2.26381
0.25098	0.14589	2.26927
0.25149	0.14634	2.27473
0.252	0.1468	2.28021
0.25251	0.14726	2.28569
0.25303	0.14773	2.29125
0.25355	0.1482	2.29679
0.25407	0.14867	2.30237
0.25459	0.14914	2.30797
0.25511	0.14962	2.31361
0.25564	0.1501	2.31923
0.25617	0.15058	2.32488
0.2567	0.15106	2.33056
0.25723	0.15155	2.33623
0.25776	0.15204	2.34197
0.2583	0.15253	2.34769
0.25884	0.15303	2.35345
0.25938	0.15353	2.35925
0.25992	0.15403	2.36506
0.26047	0.15453	2.37088
0.26102	0.15504	2.37673
0.26157	0.15555	2.38258
0.26212	0.15606	2.38846
0.26268	0.15658	2.39439
0.26324	0.1571	2.40033
0.2638	0.15763	2.40627
0.26436	0.15816	2.41226
0.26492	0.15868	2.41826
0.26549	0.15922	2.42426
0.26606	0.15975	2.43031
0.26663	0.16029	2.43637
0.26721	0.16083	2.44245
0.26778	0.16138	2.44858
0.26836	0.16193	2.45471
0.26895	0.16248	2.46089
0.26953	0.16304	2.46708
0.27012	0.1636	2.47329
0.27071	0.16416	2.47955
0.2713	0.16473	2.48581
0.2719	0.1653	2.49209
0.27249	0.16588	2.4984
0.27309	0.16645	2.50472
0.2737	0.16703	2.5111
0.2743	0.16762	2.5175
0.27491	0.16821	2.5239
0.27552	0.1688	2.53033
0.27613	0.16939	2.53677
0.27675	0.17	2.54327
0.27737	0.1706	2.5498
0.27799	0.17121	2.55635
0.27862	0.17182	2.56291
0.27924	0.17243	2.56948
0.27987	0.17305	2.57609
0.28051	0.17367	2.58274
0.28114	0.1743	2.5894
0.28178	0.17493	2.59613
0.28242	0.17557	2.60287
0.28307	0.17621	2.60965
0.28372	0.17686	2.61642
0.28437	0.1775	2.62324
0.28502	0.17816	2.63006
0.28568	0.17881	2.63691
0.28634	0.17947	2.64382
0.287	0.18014	2.65076
0.28767	0.18081	2.65772
0.28834	0.18148	2.66472
0.28901	0.18216	2.67172
0.28968	0.18284	2.67876
0.29036	0.18353	2.68581
0.29104	0.18422	2.69292
0.29173	0.18492	2.70009
0.29242	0.18563	2.70726
0.29311	0.18634	2.71445
0.2938	0.18704	2.72163
0.2945	0.18777	2.72893
0.2952	0.18849	2.73624
0.29591	0.18921	2.74356
0.29661	0.18994	2.75089
0.29732	0.19066	2.75827
0.29804	0.19142	2.76569
0.29876	0.19215	2.77312
0.29948	0.1929	2.78065
0.3002	0.19368	2.78817
0.30093	0.19442	2.79571
0.30166	0.1952	2.80327
0.3024	0.19597	2.81091
0.30314	0.19675	2.81858
0.30388	0.19754	2.82629
0.30463	0.19832	2.834
0.30538	0.19912	2.84173
0.30613	0.19991	2.8495
0.30689	0.20073	2.85732
0.30765	0.20154	2.86521
0.30842	0.20236	2.87311
0.30919	0.20317	2.88106
0.30996	0.20401	2.88902
0.31074	0.20485	2.89704
0.31152	0.20569	2.90508
0.3123	0.20653	2.91317
0.31309	0.20739	2.92127
0.31388	0.20825	2.92943
0.31468	0.20911	2.93762
0.31548	0.20999	2.94584
0.31629	0.21088	2.95411
0.3171	0.21175	2.96242
0.31791	0.21264	2.97076
0.31873	0.21355	2.97916
0.31955	0.21446	2.98757
0.32037	0.21537	2.99606
0.3212	0.21629	3.00456
0.32204	0.21722	3.01312
0.32288	0.21815	3.02172
0.32372	0.21908	3.03036
0.32457	0.22004	3.03905
0.32542	0.221	3.04778
0.32627	0.22197	3.05655
0.32714	0.22293	3.06532
0.328	0.22391	3.07419
0.32887	0.2249	3.08311
0.32975	0.2259	3.09206
0.33062	0.22689	3.10101
0.33151	0.22791	3.11005
0.3324	0.22893	3.11914
0.33329	0.22994	3.12822
0.33419	0.23097	3.13736
0.33509	0.23202	3.14656
0.336	0.23306	3.15581
0.33691	0.23413	3.16511
0.33783	0.2352	3.17448
0.33875	0.23627	3.18384
0.33968	0.23735	3.19333
0.34062	0.23845	3.20279
0.34155	0.23956	3.21238
0.3425	0.24066	3.22194
0.34345	0.24178	3.23163
0.3444	0.24291	3.2413
0.34536	0.24405	3.25093
0.34632	0.24521	3.26069
0.34729	0.24636	3.27058
0.34827	0.24753	3.28044
0.34925	0.24871	3.29042
0.35024	0.2499	3.30052
0.35123	0.25109	3.3106
0.35223	0.2523	3.32064
0.35323	0.25351	3.33081
0.35424	0.25475	3.34094
0.35526	0.256	3.3512
0.35628	0.25725	3.36157
0.3573	0.2585	3.37192
0.35834	0.25979	3.38238
0.35937	0.26107	3.39281
0.36042	0.26236	3.40336
0.36147	0.26366	3.41402
0.36253	0.26499	3.42465
0.36359	0.26632	3.43539
0.36466	0.26766	3.44611
0.36574	0.26901	3.45693
0.36682	0.27038	3.46787
0.36791	0.27175	3.47891
0.369	0.27314	3.48993
0.3701	0.27455	3.50105
0.37121	0.27597	3.51214
0.37232	0.27739	3.52334
0.37345	0.27884	3.53465
0.37457	0.28031	3.54592
0.37571	0.28178	3.55744
0.37685	0.28326	3.56879
0.378	0.28476	3.58038
0.37916	0.28628	3.59193
0.38032	0.2878	3.60372
0.38149	0.28935	3.61535
0.38267	0.2909	3.62721
0.38385	0.29247	3.63917
0.38504	0.29406	3.65109
0.38624	0.29568	3.66312
0.38745	0.29729	3.67524
0.38867	0.29893	3.68732
0.38989	0.30058	3.69951
0.39112	0.30225	3.71179
0.39236	0.30393	3.72416
0.3936	0.30564	3.73663
0.39485	0.30735	3.74919
0.39612	0.3091	3.76185
0.39739	0.31085	3.77447
0.39866	0.31262	3.78718
0.39995	0.31441	3.79998
0.40124	0.31622	3.813
0.40255	0.31806	3.82599
0.40386	0.31991	3.83905
0.40518	0.32176	3.85221
0.40651	0.32365	3.86546
0.40784	0.32557	3.87879
0.40919	0.3275	3.89208
0.41054	0.32944	3.90558
0.41191	0.33142	3.91916
0.41328	0.33341	3.93283
0.41466	0.33543	3.94671
0.41605	0.33748	3.96054
0.41746	0.33954	3.97445
0.41887	0.34161	3.98845
0.42029	0.34372	4.00252
0.42171	0.34587	4.01679
0.42315	0.34802	4.03114
0.4246	0.3502	4.04557
0.42606	0.35239	4.05995
0.42753	0.35464	4.07453
0.42901	0.35689	4.08918
0.4305	0.35918	4.1039
0.432	0.36149	4.11882
0.43351	0.36383	4.13381
0.43503	0.3662	4.14887
0.43656	0.3686	4.164
0.43811	0.37104	4.17931
0.43966	0.3735	4.1947
0.44122	0.37597	4.21015
0.4428	0.3785	4.22579
0.44439	0.38105	4.24149
0.44599	0.38364	4.25725
0.4476	0.38626	4.27319
0.44922	0.3889	4.2892
0.45085	0.39158	4.30538
0.4525	0.3943	4.32163
0.45415	0.39704	4.33793
0.45582	0.39984	4.35441
0.45751	0.40266	4.37094
0.4592	0.40554	4.38776
0.46091	0.40844	4.40452
0.46263	0.41138	4.42156
0.46436	0.41437	4.43866
0.46611	0.41739	4.45569
0.46786	0.42047	4.47312
0.46964	0.42359	4.49059
0.47142	0.42672	4.50811
0.47322	0.42992	4.5258
0.47504	0.43318	4.54364
0.47686	0.43647	4.56163
0.4787	0.43982	4.57979
0.48056	0.44322	4.59798
0.48243	0.44664	4.61633
0.48431	0.45015	4.63494
0.48621	0.4537	4.65348
0.48813	0.45732	4.67238
0.49006	0.46096	4.69121
0.492	0.46467	4.7103
0.49396	0.46843	4.72953
0.49594	0.47228	4.7489
0.49793	0.47618	4.76841
0.49994	0.48011	4.78806
0.50196	0.48417	4.80795
0.504	0.48824	4.82787
0.50606	0.49241	4.84814
0.50813	0.49664	4.86833
0.51022	0.50091	4.88875
0.51233	0.5053	4.90941
0.51446	0.50976	4.9302
0.5166	0.51427	4.95111
0.51876	0.51886	4.97214
0.52094	0.52355	4.99351
0.52314	0.52834	5.01489
0.52536	0.53318	5.03659
0.52759	0.53816	5.05842
0.52985	0.54318	5.08036
0.53212	0.54832	5.10251
0.53441	0.55355	5.12479
0.53673	0.55889	5.14736
0.53906	0.56435	5.17015
0.54142	0.56988	5.19295
0.54379	0.57555	5.21606
0.54619	0.58128	5.23917
0.5486	0.58716	5.26268
0.55104	0.59319	5.28629
0.5535	0.59929	5.3101
0.55598	0.60556	5.33411
0.55849	0.61196	5.3584
0.56101	0.61851	5.38289
0.56356	0.62519	5.40757
0.56614	0.63201	5.43235
0.56873	0.63899	5.4575
0.57136	0.6461	5.48265
0.574	0.65342	5.50817
0.57667	0.66086	5.53378
0.57937	0.66851	5.55976
0.58209	0.67633	5.58582
0.58483	0.68435	5.61207
0.5876	0.69256	5.63867
0.5904	0.70096	5.66536
0.59323	0.70957	5.69232
0.59608	0.71845	5.71954
0.59896	0.72751	5.74694
0.60187	0.73677	5.7745
0.6048	0.74635	5.80242
0.60777	0.75612	5.83024
0.61076	0.76618	5.85859
0.61378	0.77657	5.88711
0.61684	0.78719	5.91571
0.61992	0.79815	5.94467
0.62304	0.8094	5.9737
0.62618	0.82099	6.00308
0.62936	0.8329	6.03255
0.63257	0.84522	6.06229
0.63582	0.85783	6.09212
0.63909	0.87086	6.12212
0.64241	0.88437	6.15241
0.64575	0.89815	6.18269
0.64913	0.9125	6.21318
0.65255	0.92723	6.24386
0.656	0.94244	6.27465
0.65949	0.95827	6.30565
0.66302	0.97456	6.3367
0.66658	0.99142	6.36765
0.67018	1.00885	6.39889
0.67383	1.02678	6.4298
0.67751	1.04542	6.46103
0.68123	1.06475	6.49213
0.685	1.08469	6.52308
0.6888	1.10544	6.55393
0.69265	1.12692	6.58475
0.69654	1.14916	6.61525
0.70048	1.1721	6.64536
0.70446	1.19586	6.67511
0.70848	1.22072	6.70464
0.71255	1.24623	6.73351
0.71667	1.27267	6.76178
0.72084	1.30012	6.78935
0.72505	1.32829	6.81589
0.72932	1.35763	6.84172
0.73363	1.38753	6.86617
0.738	1.41881	6.88956
0.74242	1.45052	6.9113
0.74689	1.4831	6.93142
0.75142	1.51655	6.94967
0.756	1.55061	6.96595
0.76064	1.58489	6.97968
0.76533	1.61955	6.99085
0.77009	1.65413	6.99915
0.7749	1.68859	7.00438
0.77977	1.72192	7.00614
0.78471	1.75427	7.00432
0.78971	1.78488	6.99877
0.79477	1.81296	6.98941
0.7999	1.83807	6.97607
0.80509	1.85909	6.95904
0.81035	1.87531	6.93857
0.81569	1.88587	6.91538
0.82109	1.88979	6.88965
0.82656	1.88656	6.86302
0.83211	1.87539	6.83616
0.83773	1.85601	6.81056
0.84343	1.82839	6.78793
0.84921	1.79304	6.76979
0.85506	1.75087	6.75748
0.861	1.70258	6.75239
0.86702	1.64985	6.75544
0.87313	1.59457	6.76703
0.87932	1.53824	6.78728
0.8856	1.48243	6.81583
0.89197	1.42868	6.8518
0.89844	1.37779	6.89437
0.90499	1.33076	6.9419
0.91165	1.28752	6.99369
0.9184	1.24832	7.04828
0.92526	1.21266	7.10504
0.93221	1.18042	7.16271
0.93927	1.15085	7.22077
0.94644	1.12312	7.27925
0.95372	1.09684	7.33792
0.96112	1.0715	7.39616
0.96863	1.04652	7.45468
0.97625	1.02147	7.51368
0.984	0.99637	7.57296
0.99187	0.97093	7.63287
0.99987	0.94528	7.69295

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: —

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Models and simulations

About Al (Aluminium)

Aluminium (Al) is a lightweight and highly reflective metal that sees extensive use in a variety of optical applications. Known for its excellent thermal and electrical conductivity, aluminium is often utilized as a mirror coating in optical systems such as telescopes and microscopes, particularly for operations within the ultraviolet and visible spectral ranges. While it offers high reflectivity, it is also cost-effective, making it a popular choice across both consumer and industrial sectors. However, aluminium surfaces are generally more prone to oxidation than other reflective metals like gold or silver. To counteract this, aluminium coatings are frequently protected by a thin layer of dielectric material. In photonics, aluminium nanostructures are also being investigated for their plasmonic properties. It's worth noting that the optical properties of aluminium, such as its refractive index, can differ based on its physical state—whether in bulk, thin film, or nanoparticle form. Overall, aluminium remains a versatile and widely used material in the field of optics, valued for its blend of performance and affordability.

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Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/Al/nk/Cheng.yml
ID: ds_abd1b7306990
API: /v1/datasets/ds_abd1b7306990

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