Optical constants

Refractive index of NH₃ (Ammonia)

Cuthbertson and Cuthbertson 1914: n 0.480–0.671 µm

Data: formula 6
Range: 0.48–0.6708 µm
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.00038
Extinction coefficient k: 0

Permittivity ε₁: 1.00075
Permittivity ε₂: 0

Absorption coefficient α: 0 cm⁻¹
Penetration depth δ = λ/(2πk): — nm

Abbe number V_d: 45.416
Chromatic dispersion dn/dλ: -4.24332e-05 µm⁻¹

Group index n_g: 1.0004
Group velocity dispersion: 0.0812692 fs²/mm

Dispersion parameter D: -0.443367 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

# NH3 (Ammonia): Cuthbertson and Cuthbertson 1914: n 0.480–0.671 µm
nh3 = ls.fetch_refractiveindex("main", "NH3", "Cuthbertson", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(nh3.range_nm)  # (479.99, 670.785) nm
eps = nh3.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_b598937c02ce/lightsmith"
nh3 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(nh3.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (nh3/cuthbertson-cuthbertson-1914).

# ... load nh3 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=nh3)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=480, stop_nm=670, 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.

Dispersion formula

Gases (formula 6), λ in µm

n - 1 = \frac{0.032953}{90.392 - λ^{−2}}

Valid from 0.47999 to 0.670785 µm.

Coefficients as stored

C_i	Value
C1	0.0
C2	0.032953
C3	90.392

Comments and conditions

0 °C, 760 mm Hg.

References

C. Cuthbertson and M. Cuthbertson. On the refraction and dispersion of the halogens, halogen acids, ozone, steam, oxides of nitrogen and ammonia. Phil. Trans. R. Soc. Lond. A 213, 1-26 (1914)

doi:10.1098/rsta.1914.0001 info getting lost lost in the gutter on page 219 - I. On the refraction and dispersion of the halogens, halogen acids, ozone, steam, oxides of nitrogen and ammonia, Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character (1914)

Cite

Clive Cuthbertson and Maude Cuthbertson. info getting lost lost in the gutter on page 219 - I. On the refraction and dispersion of the halogens, halogen acids, ozone, steam, oxides of nitrogen and ammonia. Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character, 213, 1-26 (1914), doi:10.1098/rsta.1914.0001; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 400 wavelengths, the same grid as the API and the library

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

NH3 (Ammonia), Cuthbertson and Cuthbertson 1914: n 0.480–0.671 µm: n and k versus wavelength
λ (µm)	n
0.47999	1.000383
0.480393	1.000383
0.480796	1.000383
0.481199	1.000383
0.481603	1.000383
0.482007	1.000383
0.482412	1.000383
0.482817	1.000383
0.483222	1.000383
0.483627	1.000383
0.484033	1.000383
0.484439	1.000383
0.484846	1.000383
0.485253	1.000383
0.48566	1.000382
0.486067	1.000382
0.486475	1.000382
0.486884	1.000382
0.487292	1.000382
0.487701	1.000382
0.48811	1.000382
0.48852	1.000382
0.48893	1.000382
0.48934	1.000382
0.489751	1.000382
0.490162	1.000382
0.490573	1.000382
0.490985	1.000382
0.491397	1.000382
0.491809	1.000382
0.492222	1.000382
0.492635	1.000382
0.493048	1.000382
0.493462	1.000382
0.493876	1.000382
0.494291	1.000382
0.494705	1.000382
0.49512	1.000382
0.495536	1.000382
0.495952	1.000382
0.496368	1.000382
0.496784	1.000382
0.497201	1.000382
0.497619	1.000382
0.498036	1.000382
0.498454	1.000382
0.498872	1.000382
0.499291	1.000381
0.49971	1.000381
0.500129	1.000381
0.500549	1.000381
0.500969	1.000381
0.501389	1.000381
0.50181	1.000381
0.502231	1.000381
0.502653	1.000381
0.503075	1.000381
0.503497	1.000381
0.503919	1.000381
0.504342	1.000381
0.504765	1.000381
0.505189	1.000381
0.505613	1.000381
0.506037	1.000381
0.506462	1.000381
0.506887	1.000381
0.507312	1.000381
0.507738	1.000381
0.508164	1.000381
0.50859	1.000381
0.509017	1.000381
0.509444	1.000381
0.509872	1.000381
0.5103	1.000381
0.510728	1.000381
0.511156	1.000381
0.511585	1.000381
0.512015	1.000381
0.512444	1.000381
0.512874	1.000381
0.513305	1.000381
0.513735	1.000381
0.514167	1.00038
0.514598	1.00038
0.51503	1.00038
0.515462	1.00038
0.515895	1.00038
0.516328	1.00038
0.516761	1.00038
0.517194	1.00038
0.517628	1.00038
0.518063	1.00038
0.518498	1.00038
0.518933	1.00038
0.519368	1.00038
0.519804	1.00038
0.52024	1.00038
0.520677	1.00038
0.521114	1.00038
0.521551	1.00038
0.521989	1.00038
0.522427	1.00038
0.522865	1.00038
0.523304	1.00038
0.523743	1.00038
0.524182	1.00038
0.524622	1.00038
0.525063	1.00038
0.525503	1.00038
0.525944	1.00038
0.526386	1.00038
0.526827	1.00038
0.527269	1.00038
0.527712	1.00038
0.528155	1.00038
0.528598	1.00038
0.529041	1.00038
0.529485	1.00038
0.52993	1.00038
0.530374	1.000379
0.530819	1.000379
0.531265	1.000379
0.531711	1.000379
0.532157	1.000379
0.532603	1.000379
0.53305	1.000379
0.533498	1.000379
0.533945	1.000379
0.534393	1.000379
0.534842	1.000379
0.535291	1.000379
0.53574	1.000379
0.536189	1.000379
0.536639	1.000379
0.53709	1.000379
0.53754	1.000379
0.537992	1.000379
0.538443	1.000379
0.538895	1.000379
0.539347	1.000379
0.5398	1.000379
0.540253	1.000379
0.540706	1.000379
0.54116	1.000379
0.541614	1.000379
0.542068	1.000379
0.542523	1.000379
0.542978	1.000379
0.543434	1.000379
0.54389	1.000379
0.544347	1.000379
0.544803	1.000379
0.545261	1.000379
0.545718	1.000379
0.546176	1.000379
0.546634	1.000379
0.547093	1.000379
0.547552	1.000379
0.548012	1.000378
0.548472	1.000378
0.548932	1.000378
0.549392	1.000378
0.549853	1.000378
0.550315	1.000378
0.550777	1.000378
0.551239	1.000378
0.551701	1.000378
0.552164	1.000378
0.552628	1.000378
0.553091	1.000378
0.553556	1.000378
0.55402	1.000378
0.554485	1.000378
0.55495	1.000378
0.555416	1.000378
0.555882	1.000378
0.556349	1.000378
0.556815	1.000378
0.557283	1.000378
0.55775	1.000378
0.558218	1.000378
0.558687	1.000378
0.559156	1.000378
0.559625	1.000378
0.560094	1.000378
0.560564	1.000378
0.561035	1.000378
0.561506	1.000378
0.561977	1.000378
0.562448	1.000378
0.56292	1.000378
0.563393	1.000378
0.563866	1.000378
0.564339	1.000378
0.564812	1.000378
0.565286	1.000378
0.565761	1.000378
0.566235	1.000378
0.566711	1.000378
0.567186	1.000378
0.567662	1.000378
0.568138	1.000377
0.568615	1.000377
0.569092	1.000377
0.56957	1.000377
0.570048	1.000377
0.570526	1.000377
0.571005	1.000377
0.571484	1.000377
0.571964	1.000377
0.572444	1.000377
0.572924	1.000377
0.573405	1.000377
0.573886	1.000377
0.574368	1.000377
0.57485	1.000377
0.575332	1.000377
0.575815	1.000377
0.576298	1.000377
0.576782	1.000377
0.577266	1.000377
0.57775	1.000377
0.578235	1.000377
0.57872	1.000377
0.579206	1.000377
0.579692	1.000377
0.580178	1.000377
0.580665	1.000377
0.581152	1.000377
0.58164	1.000377
0.582128	1.000377
0.582617	1.000377
0.583106	1.000377
0.583595	1.000377
0.584085	1.000377
0.584575	1.000377
0.585065	1.000377
0.585556	1.000377
0.586048	1.000377
0.586539	1.000377
0.587032	1.000377
0.587524	1.000377
0.588017	1.000377
0.588511	1.000377
0.589004	1.000377
0.589499	1.000377
0.589993	1.000377
0.590489	1.000377
0.590984	1.000376
0.59148	1.000376
0.591976	1.000376
0.592473	1.000376
0.59297	1.000376
0.593468	1.000376
0.593966	1.000376
0.594464	1.000376
0.594963	1.000376
0.595462	1.000376
0.595962	1.000376
0.596462	1.000376
0.596963	1.000376
0.597464	1.000376
0.597965	1.000376
0.598467	1.000376
0.598969	1.000376
0.599472	1.000376
0.599975	1.000376
0.600478	1.000376
0.600982	1.000376
0.601486	1.000376
0.601991	1.000376
0.602496	1.000376
0.603002	1.000376
0.603508	1.000376
0.604014	1.000376
0.604521	1.000376
0.605029	1.000376
0.605536	1.000376
0.606044	1.000376
0.606553	1.000376
0.607062	1.000376
0.607571	1.000376
0.608081	1.000376
0.608591	1.000376
0.609102	1.000376
0.609613	1.000376
0.610125	1.000376
0.610637	1.000376
0.611149	1.000376
0.611662	1.000376
0.612175	1.000376
0.612689	1.000376
0.613203	1.000376
0.613718	1.000376
0.614233	1.000376
0.614748	1.000376
0.615264	1.000376
0.61578	1.000376
0.616297	1.000375
0.616814	1.000375
0.617332	1.000375
0.61785	1.000375
0.618368	1.000375
0.618887	1.000375
0.619407	1.000375
0.619927	1.000375
0.620447	1.000375
0.620967	1.000375
0.621488	1.000375
0.62201	1.000375
0.622532	1.000375
0.623054	1.000375
0.623577	1.000375
0.6241	1.000375
0.624624	1.000375
0.625148	1.000375
0.625673	1.000375
0.626198	1.000375
0.626723	1.000375
0.627249	1.000375
0.627776	1.000375
0.628303	1.000375
0.62883	1.000375
0.629357	1.000375
0.629886	1.000375
0.630414	1.000375
0.630943	1.000375
0.631473	1.000375
0.632003	1.000375
0.632533	1.000375
0.633064	1.000375
0.633595	1.000375
0.634127	1.000375
0.634659	1.000375
0.635191	1.000375
0.635724	1.000375
0.636258	1.000375
0.636792	1.000375
0.637326	1.000375
0.637861	1.000375
0.638396	1.000375
0.638932	1.000375
0.639468	1.000375
0.640005	1.000375
0.640542	1.000375
0.641079	1.000375
0.641617	1.000375
0.642156	1.000375
0.642695	1.000375
0.643234	1.000375
0.643774	1.000375
0.644314	1.000375
0.644855	1.000375
0.645396	1.000375
0.645937	1.000374
0.646479	1.000374
0.647022	1.000374
0.647565	1.000374
0.648108	1.000374
0.648652	1.000374
0.649196	1.000374
0.649741	1.000374
0.650286	1.000374
0.650832	1.000374
0.651378	1.000374
0.651925	1.000374
0.652472	1.000374
0.653019	1.000374
0.653567	1.000374
0.654116	1.000374
0.654665	1.000374
0.655214	1.000374
0.655764	1.000374
0.656314	1.000374
0.656865	1.000374
0.657416	1.000374
0.657968	1.000374
0.65852	1.000374
0.659073	1.000374
0.659626	1.000374
0.660179	1.000374
0.660733	1.000374
0.661288	1.000374
0.661843	1.000374
0.662398	1.000374
0.662954	1.000374
0.66351	1.000374
0.664067	1.000374
0.664624	1.000374
0.665182	1.000374
0.66574	1.000374
0.666299	1.000374
0.666858	1.000374
0.667418	1.000374
0.667978	1.000374
0.668538	1.000374
0.669099	1.000374
0.669661	1.000374
0.670223	1.000374
0.670785	1.000374

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: —

NH₃ (Ammonia): all datasets

Cuthbertson and Cuthbertson 1914: n 0.480–0.671 µm n 0.48–0.6708 µm default

About NH3 (Ammonia)

Ammonia (NH₃) is a compound of nitrogen and hydrogen, manifesting as a colorless gas with a distinct pungent smell. In the realm of optics, ammonia is notable not only for its refractive index and absorption characteristics, especially in the infrared region where it exhibits absorption bands, but also as a lasing medium. Ammonia gas has been used in far-infrared NH₃ lasers, which operate based on the molecule's inversion transitions. Industrially, ammonia plays a pivotal role in fertilizer production and also serves as a refrigerant. Its liquid form can dissolve a variety of inorganic salts, acting as a solvent. However, given its corrosive nature and potential to form explosive mixtures with air, it's imperative to handle and store ammonia with caution.

More about NH3 (Ammonia) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/NH3/nk/Cuthbertson.yml
ID: ds_b598937c02ce
API: /v1/datasets/ds_b598937c02ce

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