Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 3.311
Extinction coefficient k: 0.551824

Permittivity ε₁: 10.6582
Permittivity ε₂: 3.65418

Absorption coefficient α: 118013 cm⁻¹
Penetration depth δ = λ/(2πk): 169.473 nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: 0 µm⁻¹

Group index n_g: 3.311
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

# Ge (Germanium): Ciesielski et al. 2018: 2 nm film; n,k 0.2–2 µm
ge = ls.fetch_refractiveindex("main", "Ge", "Ciesielski-2nm", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ge.range_nm)  # (200, 2000) nm
eps = ge.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_3f95fd1b210d/lightsmith"
ge = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(ge.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (ge/ciesielski-2018-2nm).

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

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

2 nm-thick germanium film deposited directly on SiO₂ substrate

Conditions

film thickness: 2e-9
substrate: SiO2

References

A. Ciesielski, L. Skowronski, W.Pacuski, T. Szoplik. Permittivity of Ge, Te and Se thin films in the 200–1500 nm spectral range. Predicting the segregation effects in silver. Mat. Sci. Semicond. Process. 81, 64-67 (2018) (Numerical data kindly provided by Arkadiusz Ciesielski)

doi:10.1016/j.mssp.2018.03.003 Permittivity of Ge, Te and Se thin films in the 200–1500 nm spectral range. Predicting the segregation effects in silver, Materials Science in Semiconductor Processing (2018)

Cite

Arkadiusz Ciesielski, Lukasz Skowronski, Wojciech Pacuski and Tomasz Szoplik. Permittivity of Ge, Te and Se thin films in the 200–1500 nm spectral range. Predicting the segregation effects in silver. Materials Science in Semiconductor Processing, 81, 64-67 (2018), doi:10.1016/j.mssp.2018.03.003; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

278 rows as published

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

Ge (Germanium), Ciesielski et al. 2018: 2 nm film; n,k 0.2–2 µm: n and k versus wavelength
λ (µm)	n	k
0.2	1.457	1.234
0.20065	1.461	1.24
0.2013	1.466	1.245
0.20195	1.47	1.25
0.20261	1.475	1.255
0.20328	1.479	1.26
0.20395	1.484	1.265
0.20462	1.489	1.269
0.2053	1.493	1.274
0.20598	1.498	1.279
0.20667	1.503	1.284
0.20736	1.508	1.289
0.20805	1.513	1.294
0.20875	1.518	1.299
0.20946	1.523	1.304
0.21017	1.528	1.308
0.21088	1.534	1.313
0.2116	1.539	1.318
0.21233	1.544	1.323
0.21306	1.55	1.327
0.21379	1.555	1.332
0.21453	1.561	1.337
0.21528	1.567	1.341
0.21603	1.572	1.346
0.21678	1.578	1.35
0.21754	1.584	1.355
0.21831	1.59	1.36
0.21908	1.596	1.364
0.21986	1.602	1.368
0.22064	1.608	1.373
0.22143	1.614	1.377
0.22222	1.621	1.382
0.22302	1.627	1.386
0.22383	1.634	1.39
0.22464	1.64	1.395
0.22545	1.647	1.399
0.22628	1.653	1.403
0.22711	1.66	1.407
0.22794	1.667	1.412
0.22878	1.674	1.416
0.22963	1.681	1.42
0.23048	1.688	1.424
0.23134	1.695	1.428
0.23221	1.702	1.432
0.23308	1.709	1.436
0.23396	1.716	1.44
0.23485	1.724	1.444
0.23574	1.731	1.448
0.23664	1.739	1.451
0.23755	1.746	1.455
0.23846	1.754	1.459
0.23938	1.762	1.462
0.24031	1.77	1.466
0.24125	1.778	1.47
0.24219	1.786	1.473
0.24314	1.794	1.477
0.24409	1.802	1.48
0.24506	1.81	1.483
0.24603	1.818	1.487
0.24701	1.827	1.49
0.248	1.835	1.493
0.249	1.844	1.497
0.25	1.852	1.5
0.25101	1.861	1.503
0.25203	1.87	1.506
0.25306	1.879	1.509
0.2541	1.888	1.512
0.25514	1.897	1.514
0.2562	1.906	1.517
0.25726	1.915	1.52
0.25833	1.924	1.522
0.25941	1.933	1.525
0.2605	1.943	1.528
0.2616	1.952	1.53
0.26271	1.962	1.532
0.26383	1.972	1.535
0.26496	1.981	1.537
0.26609	1.991	1.539
0.26724	2.001	1.541
0.2684	2.011	1.543
0.26957	2.021	1.545
0.27074	2.031	1.547
0.27193	2.041	1.548
0.27313	2.052	1.55
0.27434	2.062	1.552
0.27556	2.073	1.553
0.27679	2.083	1.555
0.27803	2.094	1.556
0.27928	2.104	1.557
0.28054	2.115	1.558
0.28182	2.126	1.559
0.28311	2.137	1.56
0.2844	2.148	1.561
0.28571	2.159	1.562
0.28704	2.17	1.562
0.28837	2.181	1.563
0.28972	2.193	1.563
0.29108	2.204	1.563
0.29245	2.216	1.563
0.29384	2.227	1.563
0.29524	2.239	1.563
0.29665	2.251	1.563
0.29808	2.262	1.563
0.29952	2.274	1.562
0.30097	2.286	1.562
0.30244	2.298	1.561
0.30392	2.31	1.56
0.30542	2.322	1.559
0.30693	2.334	1.558
0.30846	2.347	1.557
0.31	2.359	1.555
0.31156	2.371	1.554
0.31313	2.384	1.552
0.31472	2.396	1.55
0.31633	2.409	1.548
0.31795	2.421	1.546
0.31959	2.434	1.544
0.32124	2.447	1.542
0.32292	2.459	1.539
0.32461	2.472	1.536
0.32632	2.485	1.533
0.32804	2.498	1.53
0.32979	2.511	1.527
0.33155	2.524	1.523
0.33333	2.537	1.52
0.33514	2.55	1.516
0.33696	2.563	1.512
0.3388	2.576	1.508
0.34066	2.589	1.503
0.34254	2.602	1.499
0.34444	2.615	1.494
0.34637	2.629	1.489
0.34831	2.642	1.484
0.35028	2.655	1.479
0.35227	2.668	1.473
0.35429	2.681	1.468
0.35632	2.695	1.462
0.35838	2.708	1.456
0.36047	2.721	1.449
0.36257	2.734	1.443
0.36471	2.747	1.436
0.36686	2.761	1.429
0.36905	2.774	1.422
0.37126	2.787	1.414
0.37349	2.8	1.407
0.37576	2.813	1.399
0.37805	2.826	1.391
0.38037	2.839	1.383
0.38272	2.852	1.374
0.38509	2.865	1.365
0.3875	2.878	1.356
0.38994	2.89	1.347
0.39241	2.903	1.338
0.3949	2.916	1.328
0.39744	2.928	1.318
0.4	2.941	1.308
0.4026	2.953	1.298
0.40523	2.965	1.287
0.40789	2.977	1.276
0.4106	2.989	1.265
0.41333	3.001	1.254
0.41611	3.013	1.242
0.41892	3.025	1.231
0.42177	3.036	1.219
0.42466	3.048	1.206
0.42759	3.059	1.194
0.43056	3.07	1.181
0.43357	3.081	1.168
0.43662	3.092	1.155
0.43972	3.102	1.142
0.44286	3.113	1.128
0.44604	3.123	1.115
0.44928	3.133	1.101
0.45255	3.143	1.086
0.45588	3.152	1.072
0.45926	3.162	1.057
0.46269	3.171	1.042
0.46617	3.18	1.027
0.4697	3.189	1.012
0.47328	3.197	0.997
0.47692	3.205	0.981
0.48062	3.213	0.965
0.48438	3.221	0.949
0.48819	3.229	0.933
0.49206	3.236	0.916
0.496	3.243	0.9
0.5	3.249	0.883
0.50407	3.256	0.866
0.5082	3.262	0.849
0.5124	3.267	0.832
0.51667	3.273	0.814
0.52101	3.278	0.797
0.52542	3.282	0.779
0.52991	3.287	0.762
0.53448	3.291	0.744
0.53913	3.295	0.726
0.54386	3.298	0.708
0.54867	3.301	0.69
0.55357	3.304	0.671
0.55856	3.306	0.653
0.56364	3.308	0.635
0.56881	3.309	0.616
0.57407	3.31	0.597
0.57944	3.311	0.579
0.58491	3.311	0.561
0.59048	3.311	0.542
0.59615	3.31	0.524
0.60194	3.309	0.505
0.60784	3.308	0.487
0.61386	3.306	0.468
0.62	3.304	0.45
0.62626	3.301	0.431
0.63265	3.298	0.413
0.63918	3.295	0.395
0.64583	3.29	0.377
0.65263	3.286	0.359
0.65957	3.281	0.341
0.66667	3.276	0.323
0.67391	3.27	0.306
0.68132	3.263	0.288
0.68889	3.256	0.271
0.69663	3.249	0.254
0.70455	3.241	0.238
0.71264	3.233	0.221
0.72093	3.224	0.205
0.72941	3.215	0.189
0.7381	3.206	0.174
0.74699	3.195	0.159
0.7561	3.185	0.144
0.76543	3.174	0.13
0.775	3.162	0.117
0.78481	3.15	0.103
0.79487	3.138	0.091
0.80519	3.125	0.079
0.81579	3.112	0.067
0.82667	3.098	0.057
0.83784	3.085	0.047
0.84932	3.07	0.038
0.86111	3.056	0.029
0.87324	3.041	0.022
0.88571	3.027	0.015
0.89855	3.012	0.01
0.91176	2.997	0.005
0.92537	2.983	0.002
0.93939	2.969	0.001
0.95385	2.956	0.0
0.96875	2.944	0.0
0.98413	2.934	0.0
1.0	2.924	0.0
1.0164	2.915	0.0
1.0333	2.906	0.0
1.0508	2.898	0.0
1.069	2.89	0.0
1.0877	2.883	0.0
1.1071	2.876	0.0
1.1273	2.869	0.0
1.1481	2.862	0.0
1.1698	2.856	0.0
1.1923	2.85	0.0
1.2157	2.844	0.0
1.24	2.839	0.0
1.2653	2.833	0.0
1.2917	2.828	0.0
1.3191	2.823	0.0
1.3478	2.819	0.0
1.4419	2.805	0.0
1.4762	2.801	0.0
1.5122	2.797	0.0
1.55	2.793	0.0
1.5897	2.79	0.0
1.6316	2.786	0.0
1.6757	2.783	0.0
1.7222	2.779	0.0
1.7714	2.776	0.0
1.8235	2.773	0.0
1.8788	2.77	0.0
1.9375	2.767	0.0
2.0	2.765	0.0

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