Optical constants
Refractive index of Li (Lithium)
Inagaki et al. 1976: n,k 0.326–2.07 µm
- Data
- tabulated nk
- Range
- 0.326–2.066 µm
- Points
- 33
- Licence
- CC0-1.0
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 0.194462
- Extinction coefficient k
- 2.84431
- Permittivity ε1
- -8.05227
- Permittivity ε2
- 1.10622
- Absorption coefficient α
- 608282 cm⁻¹
- Penetration depth δ = λ/(2πk)
- 32.8795 nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.192308 µm⁻¹
- Group index ng
- 0.307462
- Group velocity dispersion
- — fs²/mm
- Dispersion parameter D
- — ps/(nm·km)
- Photon energy
- 2.11001 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
# Li (Lithium): Inagaki et al. 1976: n,k 0.326–2.07 µm
li = ls.fetch_refractiveindex("main", "Li", "Inagaki", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(li.range_nm) # (326, 2066) 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_13b43bca067c/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/inagaki-1976).
# ... 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"]).
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
- doi:10.1103/physrevb.13.2305 Optical properties of solid Na and Li between 0.6 and 3.8 eV, Physical Review B (1976)
Cite
T. Inagaki, L. C. Emerson, E. T. Arakawa and M. W. Williams. Optical properties of solid Na and Li between 0.6 and 3.8 eV. Physical Review B, 13, 2305-2313 (1976), doi:10.1103/physrevb.13.2305; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
33 rows as published| λ (µm) | n | k |
|---|---|---|
| 0.326 | 0.338 | 1.4 |
| 0.335 | 0.329 | 1.45 |
| 0.344 | 0.32 | 1.5 |
| 0.354 | 0.311 | 1.55 |
| 0.365 | 0.301 | 1.61 |
| 0.376 | 0.292 | 1.66 |
| 0.387 | 0.281 | 1.72 |
| 0.4 | 0.273 | 1.78 |
| 0.413 | 0.263 | 1.84 |
| 0.428 | 0.255 | 1.9 |
| 0.443 | 0.244 | 1.99 |
| 0.459 | 0.235 | 2.08 |
| 0.477 | 0.225 | 2.19 |
| 0.496 | 0.214 | 2.33 |
| 0.517 | 0.209 | 2.43 |
| 0.539 | 0.202 | 2.58 |
| 0.564 | 0.199 | 2.69 |
| 0.59 | 0.194 | 2.86 |
| 0.62 | 0.191 | 3.04 |
| 0.653 | 0.19 | 3.22 |
| 0.689 | 0.191 | 3.42 |
| 0.729 | 0.194 | 3.62 |
| 0.775 | 0.197 | 3.88 |
| 0.827 | 0.204 | 4.14 |
| 0.886 | 0.216 | 4.43 |
| 0.954 | 0.229 | 4.81 |
| 1.033 | 0.251 | 5.2 |
| 1.127 | 0.278 | 5.7 |
| 1.24 | 0.319 | 6.28 |
| 1.378 | 0.371 | 6.98 |
| 1.55 | 0.436 | 7.87 |
| 1.771 | 0.53 | 8.99 |
| 2.066 | 0.663 | 10.5 |
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
- —