Optical constants

Refractive index of Li (Lithium)

Mathewson and Myers 1971: n,k 0.340–1.77 µm; 140 K

Data: tabulated nk
Range: 0.3397–1.771 µm
Points: 60
Temperature: 140 K
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 0.121397
Extinction coefficient k: 2.81644

Permittivity ε₁: -7.91759
Permittivity ε₂: 0.683815

Absorption coefficient α: 602321 cm⁻¹
Penetration depth δ = λ/(2πk): 33.2049 nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: 0.165331 µm⁻¹

Group index n_g: 0.0242483
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

# Li (Lithium): Mathewson and Myers 1971: n,k 0.340–1.77 µm; 140 K
li = ls.fetch_refractiveindex("main", "Li", "Mathewson-140K", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(li.range_nm)  # (339.68, 1771.2) nm
eps = li.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_b231238d7d54/lightsmith"
li = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(li.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (li/mathewson-myers-1971-140k).

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

140 K (-133.15 °C)

Conditions

temperature: 140 K

References

A. G. Mathewson and H. P. Myers. Absolute values of the optical constants of some pure metals. Phys. Scr. 4, 291-292 (1971)

doi:10.1088/0031-8949/4/6/009 Absolute Values of the Optical Constants of Some Pure Metals, Physica Scripta (1971)

Cite

A G Mathewson and H P Myers. Absolute Values of the Optical Constants of Some Pure Metals. Physica Scripta, 4, 291-292 (1971), doi:10.1088/0031-8949/4/6/009; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

60 rows as published

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

Li (Lithium), Mathewson and Myers 1971: n,k 0.340–1.77 µm; 140 K: n and k versus wavelength
λ (µm)	n	k
0.33968	0.3362	1.38312
0.3444	0.32482	1.41616
0.34925	0.31078	1.44796
0.35424	0.30068	1.48
0.35937	0.2879	1.51092
0.36466	0.27572	1.54143
0.3701	0.26407	1.57154
0.37571	0.25293	1.60124
0.38149	0.24225	1.63055
0.38745	0.23496	1.65988
0.3936	0.22507	1.68839
0.39995	0.21555	1.71653
0.40651	0.20312	1.77236
0.41328	0.19451	1.7994
0.42029	0.18619	1.82611
0.42753	0.17826	1.8793
0.43503	0.16832	1.93089
0.4428	0.16104	1.956
0.45085	0.15454	2.00596
0.4592	0.14601	2.05459
0.46786	0.13877	2.12585
0.47686	0.13351	2.17206
0.48621	0.12853	2.21732
0.49594	0.12479	2.28376
0.50606	0.12136	2.34835
0.5166	0.1182	2.41122
0.52759	0.11729	2.4726
0.53906	0.11363	2.55204
0.55104	0.11684	2.6103
0.56356	0.11914	2.68593
0.57667	0.11959	2.7594
0.5904	0.12186	2.83105
0.6048	0.12337	2.91808
0.61992	0.12489	3.0026
0.63582	0.12643	3.0848
0.65255	0.1289	3.18066
0.67018	0.13135	3.27372
0.6888	0.13317	3.37901
0.70848	0.13645	3.48118
0.72932	0.1405	3.5944
0.75142	0.14257	3.71757
0.7749	0.14627	3.86282
0.7999	0.14989	4.00281
0.82656	0.15377	4.16217
0.85506	0.1583	4.32725
0.8856	0.16192	4.50846
0.9184	0.16832	4.69343
0.95372	0.17412	4.88163
0.99187	0.18038	5.07272
1.0332	0.18659	5.33243
1.07812	0.19201	5.62467
1.12713	0.19963	5.91099
1.1808	0.20859	6.20834
1.23984	0.21693	6.54577
1.3051	0.22721	6.93193
1.3776	0.23021	7.40628
1.45864	0.24903	7.89063
1.5498	0.26543	8.38275
1.65312	0.2808	9.00993
1.7712	0.29957	9.66384

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: —

Li (Lithium): all datasets

About Li (Lithium)

Lithium (Li) is a soft, silvery-white alkali metal that is the lightest metal and the lightest solid element. It is highly reactive and flammable, requiring special handling and storage procedures. In the context of optics and photonics, lithium is used as a component in various optical materials like lithium niobate (LiNbO₃) and lithium tantalate (LiTaO₃), which are commonly used for nonlinear optics, modulators, and other optical devices due to their high electro-optic coefficients. Additionally, lithium is used in the manufacturing of specialty glasses and ceramics, contributing to their desirable optical properties. Although lithium itself is not used in optical applications, its compounds are highly valuable in the field.

More about Li (Lithium) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/Li/nk/Mathewson-140K.yml
ID: ds_b231238d7d54
API: /v1/datasets/ds_b231238d7d54

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