Optical constants

Refractive index of Al (Aluminium)

Ordal et al. 1988: n,k 0.667–200 µm

Data: tabulated nk
Range: 0.667–200 µm
Points: 51
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 31.6891
Extinction coefficient k: 100.77

Permittivity ε₁: -9150.37
Permittivity ε₂: 6386.62

Absorption coefficient α: 1.10114e+06 cm⁻¹
Penetration depth δ = λ/(2πk): 18.163 nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: 3.80315 µm⁻¹

Group index n_g: -12.047
Group velocity dispersion: — fs²/mm

Dispersion parameter D: — ps/(nm·km)
Photon energy: 0.107812 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): Ordal et al. 1988: n,k 0.667–200 µm
al = ls.fetch_refractiveindex("main", "Al", "Ordal", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(al.range_nm)  # (667, 200000) nm
eps = al.eps([11500])  # 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_320abfa87c92/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/ordal-1988).

# ... 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=667, 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.

References

M. A. Ordal, R. J. Bell, R. W. Alexander, L. A. Newquist, M. R. Querry. Optical properties of Al, Fe, Ti, Ta, W, and Mo at submillimeter wavelengths. Appl. Opt. 27, 1203-1209 (1988)

doi:10.1364/ao.27.001203 Optical properties of Al, Fe, Ti, Ta, W, and Mo at submillimeter wavelengths, Applied Optics (1988)

Cite

Mark A. Ordal, Robert J. Bell, Ralph W. Alexander, Lawrence A. Newquist and Marvin R. Querry. Optical properties of Al, Fe, Ti, Ta, W, and Mo at submillimeter wavelengths. Applied Optics, 27, 1203 (1988), doi:10.1364/ao.27.001203; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

51 rows as published

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

Al (Aluminium), Ordal et al. 1988: n,k 0.667–200 µm: n and k versus wavelength
λ (µm)	n	k
0.667	1.6232262	8.0797904
0.714	2.0208103	8.5523233
0.769	2.6528613	8.7156916
0.833	2.7846191	8.3634734
0.909	2.0063894	8.4485537
1.0	1.3789601	9.6826848
1.05	1.2553502	10.361271
1.11	1.2211025	11.108164
1.18	1.2366448	11.880035
1.25	1.2324984	12.721123
1.33	1.2712686	13.676589
1.43	1.3374754	14.766043
1.54	1.4501184	16.005291
1.67	1.6474236	17.430945
1.82	1.8892471	19.041604
2.0	2.1962737	20.969371
2.11	2.4038118	22.062867
2.22	2.6179915	23.2578
2.35	2.8842412	24.591905
2.5	3.181563	26.07382
2.67	3.569359	27.735962
2.86	4.0097886	29.575977
3.08	4.5104289	31.653186
3.33	5.0466806	34.058286
3.64	5.7888	36.878956
4.0	6.557991	40.184716
4.44	7.6669569	44.21065
5.0	8.8866481	49.131664
5.71	10.62581	55.544522
6.67	13.385937	63.967532
8.0	17.708575	75.320562
10.0	25.832564	90.72043
11.1	30.167884	98.172167
12.5	35.49229	107.26425
14.3	42.226361	117.86671
16.7	50.744867	131.07397
20.0	61.871514	148.17314
22.2	68.262241	159.23227
25.0	76.681189	174.09538
28.6	88.918176	192.23917
33.3	108.95823	213.3717
40.0	134.05166	235.70537
44.4	149.32871	248.55977
50.0	167.0781	263.04366
57.1	188.04844	279.77106
66.7	213.38844	299.72607
80.0	245.0098	324.59867
100.0	286.08777	357.47647
125.0	329.97183	393.7747
154.0	374.73526	431.44791
200.0	436.98909	485.19932

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: —

Al (Aluminium): all datasets

Experimental data

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.

More about Al (Aluminium) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/Al/nk/Ordal.yml
ID: ds_320abfa87c92
API: /v1/datasets/ds_320abfa87c92

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