At one wavelength

Refractive index n: 5.76624
Extinction coefficient k: 1.62336

Permittivity ε₁: 30.6142
Permittivity ε₂: 18.7214

Absorption coefficient α: 347171 cm⁻¹
Penetration depth δ = λ/(2πk): 57.6086 nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: 12.4 µm⁻¹

Group index n_g: -1.52
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): Jellison 1992: n,k 0.234–0.840 µm
ge = ls.fetch_refractiveindex("main", "Ge", "Jellison", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ge.range_nm)  # (234, 840) 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_564c05b4c296/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/jellison-1992).

# ... 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=840, 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

Crysal orientation: <100>; Room temperature

References

G.E. Jellison Jr. Optical functions of GaAs, GaP, and Ge determined by two-channel polarization modulation ellipsometry. Opt. Mat. 1, 151-160 (1992)

doi:10.1016/0925-3467(92)90022-f Optical functions of GaAs, GaP, and Ge determined by two-channel polarization modulation ellipsometry, Optical Materials (1992)

Cite

G.E. Jellison. Optical functions of GaAs, GaP, and Ge determined by two-channel polarization modulation ellipsometry. Optical Materials, 1, 151-160 (1992), doi:10.1016/0925-3467(92)90022-f; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

187 rows as published

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

Ge (Germanium), Jellison 1992: n,k 0.234–0.840 µm: n and k versus wavelength
λ (µm)	n	k
0.234	1.444	3.009
0.236	1.474	3.036
0.238	1.421	3.047
0.24	1.413	3.085
0.242	1.431	3.144
0.244	1.441	3.181
0.246	1.457	3.232
0.248	1.472	3.286
0.25	1.488	3.343
0.252	1.507	3.394
0.254	1.529	3.455
0.256	1.552	3.521
0.258	1.576	3.584
0.26	1.608	3.66
0.262	1.647	3.729
0.264	1.684	3.806
0.266	1.724	3.885
0.268	1.783	3.977
0.27	1.842	4.069
0.272	1.902	4.172
0.274	1.999	4.292
0.276	2.107	4.412
0.278	2.263	4.545
0.28	2.468	4.665
0.282	2.72	4.731
0.284	2.996	4.731
0.286	3.248	4.656
0.288	3.461	4.53
0.29	3.624	4.385
0.292	3.756	4.234
0.294	3.831	4.087
0.296	3.891	3.954
0.298	3.926	3.836
0.3	3.957	3.725
0.302	3.973	3.627
0.304	3.986	3.541
0.306	3.989	3.466
0.308	3.993	3.398
0.31	4.002	3.333
0.312	4.01	3.273
0.314	4.016	3.222
0.316	4.009	3.18
0.318	4.016	3.135
0.32	4.019	3.098
0.322	4.024	3.062
0.324	4.031	3.025
0.326	4.031	2.993
0.328	4.035	2.96
0.33	4.038	2.932
0.332	4.046	2.904
0.334	4.057	2.876
0.336	4.056	2.853
0.338	4.064	2.828
0.34	4.067	2.802
0.342	4.076	2.779
0.344	4.082	2.758
0.346	4.082	2.74
0.348	4.091	2.72
0.35	4.101	2.697
0.352	4.107	2.679
0.354	4.112	2.663
0.356	4.118	2.645
0.358	4.128	2.627
0.36	4.137	2.609
0.362	4.147	2.592
0.364	4.161	2.57
0.366	4.172	2.553
0.368	4.184	2.533
0.37	4.19	2.514
0.372	4.201	2.494
0.374	4.211	2.471
0.376	4.223	2.446
0.378	4.23	2.423
0.38	4.232	2.401
0.382	4.238	2.375
0.384	4.238	2.355
0.386	4.242	2.332
0.388	4.245	2.309
0.39	4.247	2.285
0.392	4.245	2.263
0.394	4.239	2.239
0.396	4.234	2.218
0.398	4.231	2.195
0.4	4.223	2.181
0.402	4.215	2.165
0.404	4.203	2.151
0.406	4.193	2.14
0.408	4.181	2.129
0.41	4.169	2.122
0.412	4.16	2.116
0.414	4.155	2.108
0.416	4.146	2.106
0.418	4.138	2.102
0.42	4.13	2.102
0.422	4.125	2.102
0.424	4.12	2.103
0.426	4.101	2.111
0.428	4.097	2.113
0.43	4.099	2.116
0.432	4.097	2.122
0.434	4.095	2.127
0.436	4.097	2.132
0.438	4.1	2.136
0.44	4.102	2.143
0.442	4.104	2.15
0.444	4.106	2.157
0.446	4.111	2.163
0.448	4.114	2.171
0.45	4.121	2.177
0.455	4.138	2.195
0.46	4.158	2.214
0.465	4.182	2.234
0.47	4.208	2.256
0.475	4.241	2.273
0.48	4.273	2.291
0.485	4.318	2.309
0.49	4.359	2.331
0.495	4.407	2.348
0.5	4.46	2.366
0.505	4.521	2.382
0.51	4.592	2.395
0.515	4.667	2.408
0.52	4.756	2.414
0.525	4.857	2.404
0.53	4.957	2.378
0.535	5.062	2.314
0.54	5.136	2.242
0.545	5.186	2.166
0.55	5.226	2.106
0.555	5.26	2.056
0.56	5.3	2.019
0.565	5.349	1.988
0.57	5.42	1.964
0.575	5.521	1.925
0.58	5.635	1.837
0.585	5.734	1.705
0.59	5.796	1.548
0.595	5.811	1.389
0.6	5.791	1.241
0.605	5.759	1.119
0.61	5.71	1.011
0.615	5.66	0.924
0.62	5.608	0.851
0.625	5.552	0.791
0.63	5.494	0.734
0.635	5.449	0.691
0.64	5.403	0.651
0.645	5.36	0.614
0.65	5.318	0.585
0.655	5.278	0.556
0.66	5.245	0.532
0.665	5.203	0.508
0.67	5.173	0.49
0.675	5.141	0.47
0.68	5.114	0.454
0.685	5.086	0.439
0.69	5.06	0.424
0.695	5.035	0.411
0.7	5.008	0.397
0.705	4.985	0.386
0.71	4.965	0.376
0.715	4.944	0.367
0.72	4.932	0.356
0.725	4.913	0.348
0.73	4.894	0.342
0.735	4.876	0.332
0.74	4.856	0.324
0.745	4.845	0.319
0.75	4.826	0.312
0.755	4.812	0.305
0.76	4.797	0.298
0.765	4.782	0.293
0.77	4.769	0.289
0.775	4.758	0.283
0.78	4.74	0.276
0.785	4.734	0.271
0.79	4.718	0.266
0.795	4.709	0.263
0.8	4.699	0.259
0.805	4.691	0.252
0.81	4.679	0.255
0.815	4.67	0.253
0.82	4.655	0.245
0.825	4.649	0.237
0.83	4.644	0.237
0.835	4.628	0.24
0.84	4.626	0.237

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