Optical constants
Refractive index of H2 (Hydrogen)
Koch 1913: n 0.230–0.546 µm
- Data
- tabulated n
- Range
- 0.2302–0.5462 µm
- Points
- 20
- Temperature
- 287 K
- Licence
- CC0-1.0
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 1.00014
- Extinction coefficient k
- 0
- Permittivity ε1
- 1.00029
- Permittivity ε2
- 0
- Absorption coefficient α
- 0 cm⁻¹
- Penetration depth δ = λ/(2πk)
- — nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -4.59780e-05 µm⁻¹
- Group index ng
- 1.00016
- Group velocity dispersion
- — fs²/mm
- Dispersion parameter D
- — ps/(nm·km)
- Photon energy
- 3.49251 eV
ε = (n + ik)², α = 4πk/λ, ng = 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
# H2 (Hydrogen): Koch 1913: n 0.230–0.546 µm
h2 = ls.fetch_refractiveindex("main", "H2", "Koch", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(h2.range_nm) # (230.2, 546.2) nm
eps = h2.eps([355]) # complex permittivityDownloads 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_7fd4f3aad56d/lightsmith"
h2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(h2.source) # citation and provenance travel with the dataAny dataset here, as the library's Tabulated material (h2/koch-1913).
# ... load h2 as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=h2)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=546, num=81),
)
res = ls.solve(sim) # exact Mie for a sphere
print(res.q_ext) # extinction efficiency at each wavelengthSame spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).
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
Conditions
- temperature
- 287 K
References
Cite
J. Koch. Über die Dispersion gasförmiger Körper im ultra-violetten Spektrum. Ark. Mat. Astron. Fys. 8, 20 (1913); Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
20 rows as published| λ (µm) | n |
|---|---|
| 0.2302 | 1.000159425 |
| 0.2379 | 1.000157703 |
| 0.2447 | 1.000156297 |
| 0.2464 | 1.000155976 |
| 0.2535 | 1.000154684 |
| 0.2577 | 1.000154012 |
| 0.2675 | 1.000152526 |
| 0.2753 | 1.000151495 |
| 0.276 | 1.000151415 |
| 0.2857 | 1.000150275 |
| 0.2894 | 1.000149878 |
| 0.2926 | 1.000149522 |
| 0.2968 | 1.000149115 |
| 0.3342 | 1.00014611 |
| 0.3544 | 1.000144945 |
| 0.3907 | 1.000143276 |
| 0.3985 | 1.000142981 |
| 0.4109 | 1.000142537 |
| 0.4917 | 1.000140532 |
| 0.5462 | 1.00013966 |
Optical transmission calculator
Free-standing sample in vacuum, normal incidence- Transmittance T
- —
- Reflectance R
- —
Fresnel reflection calculator
- Rp
- —
- Rs
- —
- R = (Rp+Rs)/2
- —
- Phase φp
- —
- Phase φs
- —
- Brewster angle θB
- —
- Critical angle θC
- —
14 °C