Optical constants
Refractive index of BDNL4 (LightPath)
BDNL4: n,k 1–14 µm
- Data
- tabulated n + tabulated k
- Range
- 1–14 µm
- Points
- 8
- Temperature
- 293 K
- Licence
- CC0-1.0
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 2.6496
- Extinction coefficient k
- 7.54400e-07
- Permittivity ε1
- 7.02038
- Permittivity ε2
- 3.99772e-06
- Absorption coefficient α
- 0.0253478 cm⁻¹
- Penetration depth δ = λ/(2πk)
- 7.89024e+08 nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.01 µm⁻¹
- Group index ng
- 2.687
- Group velocity dispersion
- — fs²/mm
- Dispersion parameter D
- — ps/(nm·km)
- Photon energy
- 0.331509 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
# BDNL4 (LightPath): BDNL4
lightpath_bdnl4 = ls.fetch_refractiveindex("specs", "LightPath-infrared", "BDNL4", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(lightpath_bdnl4.range_nm) # (1000, 14000) nm
eps = lightpath_bdnl4.eps([3740]) # 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_d91ec25bd319/lightsmith"
lightpath_bdnl4 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(lightpath_bdnl4.source) # citation and provenance travel with the dataAny dataset here, as the library's Tabulated material (lightpath-bdnl4/lightpath).
# ... load lightpath_bdnl4 as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=lightpath_bdnl4)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=1000, stop_nm=14000, 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
- 293 K
Properties
- density
- value: 4500
- thermal expansion
- value: 25.2e-06
- thermal dispersion
- type: dn/dT, value: -16.3e-6, temperature: 295, wavelength range: 8 12; type: dn/dT, value: -14.3e-6, temperature: 295, wavelength range: 3 5; type: dn/dT, value: -9.7e-6, temperature: 295, wavelength range: 1 2
- transformation temperature
- value: 478
- thermal conductivity
- value: 0.17
- hardness
- type: Vickers, value: 1.48e9
- youngs modulus
- value: 14.2e9
Thermo-optic coefficient
- dn/dT = -1.63e-05 K⁻¹, 295 K
- dn/dT = -1.43e-05 K⁻¹, 295 K
- dn/dT = -9.70e-06 K⁻¹, 295 K
References
Cite
BLACK DIAMOND BDNL4 Glass Datasheet (revision 2024-04-04); Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
Computed on 8 wavelengths, the same grid as the API and the library| λ (µm) | n | k |
|---|---|---|
| 1 | 2.754 | 5.700000e-07 |
| 2 | 2.667 | 5.100000e-07 |
| 4 | 2.647 | 7.700000e-07 |
| 6 | 2.643 | 1.350000e-06 |
| 8 | 2.639 | 6.700000e-06 |
| 10 | 2.636 | 2.870000e-06 |
| 12 | 2.632 | 8.391000e-05 |
| 14 | 2.628 | 7.250000e-05 |
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
- —
20 °C.