Optical constants
Refractive index of Na (Sodium)
Ives and Briggs 1937: n,k 0.254–0.578 µm
- Data
- tabulated nk
- Range
- 0.2536–0.578 µm
- Points
- 8
- State
- solid
- Licence
- CC0-1.0
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 0.0447204
- Extinction coefficient k
- 1.49441
- Permittivity ε1
- -2.23126
- Permittivity ε2
- 0.133661
- Absorption coefficient α
- 490321 cm⁻¹
- Penetration depth δ = λ/(2πk)
- 40.7896 nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- 0.151134 µm⁻¹
- Group index ng
- -0.0131637
- Group velocity dispersion
- — fs²/mm
- Dispersion parameter D
- — ps/(nm·km)
- Photon energy
- 3.23719 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
# Na (Sodium): Ives and Briggs 1937: n,k 0.254–0.578 µm
na = ls.fetch_refractiveindex("main", "Na", "Ives", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(na.range_nm) # (253.6, 578) nm
eps = na.eps([383]) # 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_8eb0a985f8e7/lightsmith"
na = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(na.source) # citation and provenance travel with the dataAny dataset here, as the library's Tabulated material (na/ives-briggs-1937).
# ... load na as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=na)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=578, 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.
References
- doi:10.1364/josa.27.000181 The Optical Constants of Sodium, Journal of the Optical Society of America (1937)
Cite
Herbert E. Ives and H. B. Briggs. The Optical Constants of Sodium. Journal of the Optical Society of America, 27, 181 (1937), doi:10.1364/josa.27.000181; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
8 rows as published| λ (µm) | n | k |
|---|---|---|
| 0.2536 | 0.026 | 0.621 |
| 0.2652 | 0.028 | 0.735 |
| 0.3126 | 0.04 | 1.02 |
| 0.365 | 0.042 | 1.44 |
| 0.4047 | 0.048 | 1.56 |
| 0.4358 | 0.048 | 1.8 |
| 0.5461 | 0.029 | 2.32 |
| 0.578 | 0.027 | 2.59 |
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
- —