Optical constants
Refractive index of GaP (Gallium phosphide)
Parsons and Coleman 1971: n 54.4–366 µm
- Data
- tabulated n
- Range
- 54.37–366 µm
- Points
- 17
- Licence
- CC0-1.0
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 3.35175
- Extinction coefficient k
- 0
- Permittivity ε1
- 11.2342
- Permittivity ε2
- 0
- Absorption coefficient α
- 0 cm⁻¹
- Penetration depth δ = λ/(2πk)
- — nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.000198586 µm⁻¹
- Group index ng
- 3.37975
- Group velocity dispersion
- — fs²/mm
- Dispersion parameter D
- — ps/(nm·km)
- Photon energy
- 0.00879321 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
# GaP (Gallium phosphide): Parsons and Coleman 1971: n 54.4–366 µm
gap = ls.fetch_refractiveindex("main", "GaP", "Parsons", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(gap.range_nm) # (54369, 366030) nm
eps = gap.eps([141000]) # 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_ea4bd1811cb0/lightsmith"
gap = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(gap.source) # citation and provenance travel with the dataAny dataset here, as the library's Tabulated material (gap/parsons-coleman-1971).
# ... load gap as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=gap)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=54370, stop_nm=366000, 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
References
- doi:10.1364/ao.10.1683_1 Far Infrared Optical Constants of Gallium Phosphide, Applied Optics (1971)
Cite
D. F. Parsons and P. D. Coleman. Far Infrared Optical Constants of Gallium Phosphide. Applied Optics, 10, 1683_1 (1971), doi:10.1364/ao.10.1683_1; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
17 rows as published| λ (µm) | n |
|---|---|
| 54.369 | 3.444 |
| 57.048 | 3.4302 |
| 59.602 | 3.4238 |
| 61.728 | 3.4134 |
| 66.684 | 3.401 |
| 71.803 | 3.3922 |
| 77.797 | 3.383 |
| 84.962 | 3.3754 |
| 90.992 | 3.3706 |
| 106.15 | 3.3621 |
| 113.74 | 3.3584 |
| 138.75 | 3.3522 |
| 168.46 | 3.3463 |
| 188.79 | 3.345 |
| 216.59 | 3.3438 |
| 296.21 | 3.3399 |
| 366.03 | 3.3407 |
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