Optical constants

Refractive index of Ta (Tantalum)

Werner et al. 2009: DFT calculations; n,k 0.0176–2.48 µm

Data: tabulated nk
Range: 0.01759–2.48 µm
Points: 150
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.94993
Extinction coefficient k: 2.13454

Permittivity ε₁: -0.754059
Permittivity ε₂: 8.3244

Absorption coefficient α: 456492 cm⁻¹
Penetration depth δ = λ/(2πk): 43.8124 nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: -11.597 µm⁻¹

Group index n_g: 8.76431
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

# Ta (Tantalum): Werner et al. 2009: DFT calculations; n,k 0.0176–2.48 µm
ta = ls.fetch_refractiveindex("main", "Ta", "Werner-DFT", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ta.range_nm)  # (17.586, 2479.68) nm
eps = ta.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_2f2e17fdef0e/lightsmith"
ta = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(ta.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (ta/werner-2009-dft).

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

Theoretical density function theory (DFT) calculations.

References

W. S. M. Werner, K. Glantschnig, C. Ambrosch-Draxl. Optical constants and inelastic electron-scattering data for 17 elemental metals. J. Phys Chem Ref. Data 38, 1013-1092 (2009)

doi:10.1063/1.3243762 Optical Constants and Inelastic Electron-Scattering Data for 17 Elemental Metals, Journal of Physical and Chemical Reference Data (2009)

Cite

Wolfgang S. M. Werner, Kathrin Glantschnig and Claudia Ambrosch-Draxl. Optical Constants and Inelastic Electron-Scattering Data for 17 Elemental Metals. Journal of Physical and Chemical Reference Data, 38, 1013-1092 (2009), doi:10.1063/1.3243762; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

150 rows as published

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

Ta (Tantalum), Werner et al. 2009: DFT calculations; n,k 0.0176–2.48 µm: n and k versus wavelength
λ (µm)	n	k
0.017586	0.8673	0.0357
0.017712	0.8645	0.037
0.017839	0.8623	0.0394
0.017969	0.8618	0.0412
0.0181	0.8612	0.0412
0.018233	0.8588	0.0402
0.018368	0.8548	0.0409
0.018505	0.8537	0.0422
0.018644	0.8502	0.0423
0.018785	0.8467	0.0431
0.018929	0.8419	0.0434
0.019074	0.8391	0.0459
0.019222	0.8368	0.0466
0.019373	0.8331	0.0444
0.019525	0.8223	0.0462
0.01968	0.8154	0.054
0.019837	0.8141	0.0608
0.019997	0.8068	0.0626
0.02016	0.8067	0.0762
0.020325	0.8161	0.0839
0.020493	0.8249	0.08
0.020664	0.8281	0.0688
0.020838	0.8152	0.0595
0.021014	0.8023	0.0611
0.021194	0.7915	0.0663
0.021377	0.7876	0.0724
0.021562	0.7803	0.0769
0.021752	0.7775	0.0804
0.021944	0.7749	0.0865
0.02214	0.7705	0.0818
0.022339	0.7582	0.0831
0.022543	0.7414	0.0931
0.022749	0.7426	0.1071
0.02296	0.7484	0.1229
0.023175	0.7503	0.1
0.023393	0.7264	0.0984
0.023616	0.7084	0.1087
0.023843	0.6932	0.1205
0.024075	0.6853	0.1401
0.024311	0.6741	0.1498
0.024551	0.6723	0.1733
0.024797	0.6748	0.1741
0.025047	0.6572	0.1788
0.025303	0.638	0.1975
0.025564	0.6237	0.2237
0.02583	0.618	0.2605
0.026102	0.6313	0.2891
0.02638	0.6483	0.307
0.026663	0.6504	0.3083
0.026953	0.6507	0.3397
0.027249	0.672	0.3356
0.027552	0.6649	0.3392
0.027862	0.6695	0.3495
0.028178	0.6441	0.3462
0.028502	0.6383	0.3666
0.028834	0.603	0.3881
0.029173	0.5766	0.4249
0.02952	0.5777	0.4804
0.029876	0.5569	0.5081
0.03024	0.5411	0.5628
0.030613	0.5366	0.6541
0.030996	0.5197	0.761
0.031388	0.55	0.9473
0.031791	0.8271	1.2084
0.032204	0.9589	1.0205
0.032627	1.3389	1.0811
0.033062	1.2696	0.8018
0.033509	1.3363	0.791
0.033968	1.4107	0.7099
0.03444	1.4477	0.5744
0.034925	1.4561	0.4725
0.035424	1.3969	0.32
0.035937	1.2823	0.3069
0.036466	1.2014	0.3637
0.03701	1.4703	0.4458
0.037571	1.4463	0.1366
0.038149	1.2934	0.0947
0.038745	1.2223	0.0769
0.03936	1.1527	0.0694
0.039995	1.0981	0.0765
0.040651	1.0586	0.0926
0.041328	1.0308	0.0926
0.042029	0.9983	0.0977
0.042753	0.9699	0.1083
0.043503	0.9477	0.1055
0.04428	0.9168	0.1025
0.045085	0.8723	0.1043
0.04592	0.8263	0.1216
0.046786	0.7957	0.1452
0.047686	0.7549	0.1609
0.048621	0.7111	0.1941
0.049594	0.6626	0.2347
0.050606	0.6083	0.3115
0.05166	0.6117	0.5256
0.052759	0.8659	0.3973
0.053906	0.7647	0.3504
0.055104	0.7344	0.3513
0.056356	0.7049	0.3618
0.057667	0.6511	0.3886
0.05904	0.6648	0.4219
0.06048	0.6184	0.4018
0.061992	0.5425	0.4258
0.063582	0.4719	0.5298
0.065255	0.5031	0.5605
0.067018	0.3425	0.6263
0.06888	0.3215	0.8071
0.070848	0.3705	1.0001
0.072932	0.5661	1.0466
0.075142	0.4983	1.0837
0.07749	0.5812	1.2397
0.07999	0.7527	1.2761
0.082656	0.8947	1.2769
0.085506	0.9318	1.1521
0.08856	0.9049	1.1366
0.09184	0.8992	1.1183
0.095372	0.7983	1.1486
0.099187	0.7735	1.2702
0.10332	0.8264	1.345
0.107812	0.8409	1.3777
0.112713	0.8319	1.5242
0.11808	0.8741	1.6056
0.123984	0.9577	1.7197
0.13051	1.0997	1.8059
0.13776	1.2245	1.7828
0.145864	1.202	1.6543
0.15498	0.9476	1.7703
0.165312	0.8858	2.0586
0.17712	0.8998	2.4351
0.190745	1.0689	2.9386
0.20664	1.4948	3.4329
0.225426	2.5487	3.8223
0.247968	3.395	2.7084
0.261019	3.2261	2.3168
0.27552	2.9543	2.2002
0.291728	2.7929	2.2466
0.30996	2.7339	2.3614
0.330625	2.7838	2.4981
0.354241	2.9333	2.5795
0.38149	3.125	2.5387
0.413281	3.2177	2.368
0.450852	3.1687	2.1623
0.495937	2.9195	1.9515
0.551041	2.3739	1.9009
0.619921	1.5751	2.3411
0.708481	1.1213	3.3661
0.826561	0.9721	4.4717
0.991874	0.8403	5.8339
1.239842	0.7721	7.8453
1.653123	0.9891	11.0644
2.479684	1.8892	17.0892

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: —

Ta (Tantalum): all datasets

Experimental data

Models and simulations

Werner et al. 2009: DFT calculations; n,k 0.0176–2.48 µm n,k 0.01759–2.48 µm

About Ta (Tantalum)

Tantalum (Ta) is a dense, hard, grayish-blue metal that is highly corrosion-resistant. It is part of the refractory metals group, which are characterized by their high melting points and resistance to wear, corrosion, and deformation. Due to its inertness, tantalum is often used in the manufacture of medical implants and surgical instruments, ensuring they don't react with bodily fluids. In the electronics industry, tantalum is used to make capacitors, which are key components in many electronic devices, especially mobile phones and computers. Its ability to form a stable oxide layer on its surface, known as tantalum pentoxide, is crucial for this application. Additionally, the metal is used in the production of superalloys for jet engine components, nuclear reactors, and missile parts due to its high-temperature strength and melting point.

More about Ta (Tantalum) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/Ta/nk/Werner-DFT.yml
ID: ds_2f2e17fdef0e
API: /v1/datasets/ds_2f2e17fdef0e

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