Optical constants
Refractive index of Ag (Silver)
Johnson and Christy 1972: n,k 0.188–1.94 µm
- Data
- tabulated nk
- Range
- 0.1879–1.937 µm
- Points
- 49
- Licence
- CC0-1.0
- Lightsmith
- bundled, default
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 0.051585
- Extinction coefficient k
- 3.9046
- Permittivity ε1
- -15.2432
- Permittivity ε2
- 0.402838
- Absorption coefficient α
- 835035 cm⁻¹
- Penetration depth δ = λ/(2πk)
- 23.9511 nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- 0.288184 µm⁻¹
- Group index ng
- -0.117752
- 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
# Ag (Silver): Johnson and Christy 1972: n,k 0.188–1.94 µm
ag = ls.LibraryMaterial(name="Ag", dataset="Johnson-Christy")
print(ag.range_nm) # (187.9, 1937) nm
eps = ag.eps([633]) # complex permittivity
Ships with the library: works offline and is the library's own default dataset choice.
import lightsmith as ls
# Ag (Silver): Johnson and Christy 1972: n,k 0.188–1.94 µm
ag = ls.fetch_refractiveindex("main", "Ag", "Johnson", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ag.range_nm) # (187.9, 1937) nm
eps = ag.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_3c55dea38b84/lightsmith"
ag = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(ag.source) # citation and provenance travel with the data
Any dataset here, as the library's Tabulated material (ag/johnson-christy-1972).
# ... load ag as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=ag)],
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.
Comments and conditions
References
- doi:10.1103/physrevb.6.4370 Optical Constants of the Noble Metals, Physical Review B (1972)
Cite
P. B. Johnson and R. W. Christy. Optical Constants of the Noble Metals. Physical Review B, 6, 4370-4379 (1972), doi:10.1103/physrevb.6.4370; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
49 rows as published| λ (µm) | n | k |
|---|---|---|
| 0.1879 | 1.07 | 1.212 |
| 0.1916 | 1.1 | 1.232 |
| 0.1953 | 1.12 | 1.255 |
| 0.1993 | 1.14 | 1.277 |
| 0.2033 | 1.15 | 1.296 |
| 0.2073 | 1.18 | 1.312 |
| 0.2119 | 1.2 | 1.325 |
| 0.2164 | 1.22 | 1.336 |
| 0.2214 | 1.25 | 1.342 |
| 0.2262 | 1.26 | 1.344 |
| 0.2313 | 1.28 | 1.357 |
| 0.2371 | 1.28 | 1.367 |
| 0.2426 | 1.3 | 1.378 |
| 0.249 | 1.31 | 1.389 |
| 0.2551 | 1.33 | 1.393 |
| 0.2616 | 1.35 | 1.387 |
| 0.2689 | 1.38 | 1.372 |
| 0.2761 | 1.41 | 1.331 |
| 0.2844 | 1.41 | 1.264 |
| 0.2924 | 1.39 | 1.161 |
| 0.3009 | 1.34 | 0.964 |
| 0.3107 | 1.13 | 0.616 |
| 0.3204 | 0.81 | 0.392 |
| 0.3315 | 0.17 | 0.829 |
| 0.3425 | 0.14 | 1.142 |
| 0.3542 | 0.1 | 1.419 |
| 0.3679 | 0.07 | 1.657 |
| 0.3815 | 0.05 | 1.864 |
| 0.3974 | 0.05 | 2.07 |
| 0.4133 | 0.05 | 2.275 |
| 0.4305 | 0.04 | 2.462 |
| 0.4509 | 0.04 | 2.657 |
| 0.4714 | 0.05 | 2.869 |
| 0.4959 | 0.05 | 3.093 |
| 0.5209 | 0.05 | 3.324 |
| 0.5486 | 0.06 | 3.586 |
| 0.5821 | 0.05 | 3.858 |
| 0.6168 | 0.06 | 4.152 |
| 0.6595 | 0.05 | 4.483 |
| 0.7045 | 0.04 | 4.838 |
| 0.756 | 0.03 | 5.242 |
| 0.8211 | 0.04 | 5.727 |
| 0.892 | 0.04 | 6.312 |
| 0.984 | 0.04 | 6.992 |
| 1.088 | 0.04 | 7.795 |
| 1.216 | 0.09 | 8.828 |
| 1.393 | 0.13 | 10.1 |
| 1.61 | 0.15 | 11.85 |
| 1.937 | 0.24 | 14.08 |
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
- —
Room temperature