Optical constants
Refractive index of ZnGeP2 (Zinc germanium phosphide, ZGP)
Ghosh 1998: n(e) 0.7–12 µm; 200 K
- Data
- formula 2
- Range
- 0.7–12 µm
- Temperature
- 200 K
- Optical axis
- e
- Licence
- CC0-1.0
Uniaxial crystal, axes: oe
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 3.15501
- Extinction coefficient k
- 0
- Permittivity ε1
- 9.9541
- Permittivity ε2
- 0
- Absorption coefficient α
- 0 cm⁻¹
- Penetration depth δ = λ/(2πk)
- — nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.0119813 µm⁻¹
- Group index ng
- 3.18976
- Group velocity dispersion
- 411.353 fs²/mm
- Dispersion parameter D
- -92.1338 ps/(nm·km)
- Photon energy
- 0.427532 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
# ZnGeP2 (Zinc germanium phosphide, ZGP): Ghosh 1998: n(e) 0.7–12 µm; 200 K
zngep2 = ls.fetch_refractiveindex("main", "ZnGeP2", "Ghosh-200K-e", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(zngep2.range_nm) # (700, 12000) nm
eps = zngep2.eps([2900]) # 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_9a399c4fce45/lightsmith"
zngep2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(zngep2.source) # citation and provenance travel with the dataAny dataset here, as the library's Tabulated material (zngep2/ghosh-1998-200k-e).
# ... load zngep2 as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=zngep2)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=700, stop_nm=1000, 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"]).
import json, urllib.request
import lightsmith as ls
url = "https://materials.lightsmith.dev/v1/datasets/ds_9a399c4fce45/lightsmith?model=drude_lorentz"
zngep2_dl = ls.DrudeLorentz.model_validate(json.load(urllib.request.urlopen(url)))A dispersive Drude–Lorentz model for time-domain solvers.
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.
Dispersion formula
Sellmeier (C in µm²) (formula 2), λ in µmValid from 0.7 to 12.0 µm.
Coefficients as stored
| Ci | Value |
|---|---|
| C1 | 3.59314629 |
| C2 | 5.29268202 |
| C3 | 0.13772522 |
| C4 | 2.1045154 |
| C5 | 900.0 |
Comments and conditions
Conditions
- temperature
- 200 K
- direction
- e
References
G. Ghosh.
Sellmeier coefficients for the birefringence and refractive indices of ZnGeP2 nonlinear crystal at different temperatures.
Appl. Opt., 37, 1205-1212 (1998)
- doi:10.1364/ao.37.001205 Sellmeier coefficients for the birefringence and refractive indices of ZnGeP_2 nonlinear crystal at different temperatures, Applied Optics (1998)
Cite
Gorachand Ghosh. Sellmeier coefficients for the birefringence and refractive indices of ZnGeP_2 nonlinear crystal at different temperatures. Applied Optics, 37, 1205 (1998), doi:10.1364/ao.37.001205; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
Computed on 400 wavelengths, the same grid as the API and the library
CSV comma separated
TXT tab separated
YAML n, k
Full database record original YAML
All quantities CSV
JSON metadata
| λ (µm) | n |
|---|---|
| 0.7 | 3.457442 |
| 0.705003 | 3.451581 |
| 0.710042 | 3.445855 |
| 0.715117 | 3.440261 |
| 0.720228 | 3.434795 |
| 0.725375 | 3.429453 |
| 0.73056 | 3.424232 |
| 0.735781 | 3.419127 |
| 0.74104 | 3.414136 |
| 0.746336 | 3.409254 |
| 0.75167 | 3.40448 |
| 0.757043 | 3.39981 |
| 0.762453 | 3.395241 |
| 0.767903 | 3.39077 |
| 0.773391 | 3.386394 |
| 0.778919 | 3.382112 |
| 0.784486 | 3.377919 |
| 0.790093 | 3.373815 |
| 0.79574 | 3.369797 |
| 0.801427 | 3.365861 |
| 0.807155 | 3.362007 |
| 0.812924 | 3.358232 |
| 0.818734 | 3.354534 |
| 0.824585 | 3.350911 |
| 0.830479 | 3.34736 |
| 0.836414 | 3.343882 |
| 0.842392 | 3.340472 |
| 0.848413 | 3.33713 |
| 0.854477 | 3.333855 |
| 0.860584 | 3.330643 |
| 0.866735 | 3.327495 |
| 0.87293 | 3.324408 |
| 0.879169 | 3.32138 |
| 0.885452 | 3.318411 |
| 0.891781 | 3.315499 |
| 0.898154 | 3.312643 |
| 0.904574 | 3.309841 |
| 0.911039 | 3.307092 |
| 0.91755 | 3.304395 |
| 0.924108 | 3.301748 |
| 0.930713 | 3.299151 |
| 0.937365 | 3.296602 |
| 0.944064 | 3.294101 |
| 0.950812 | 3.291646 |
| 0.957607 | 3.289236 |
| 0.964451 | 3.28687 |
| 0.971345 | 3.284547 |
| 0.978287 | 3.282266 |
| 0.985279 | 3.280027 |
| 0.992321 | 3.277828 |
| 0.999413 | 3.275669 |
| 1.00656 | 3.273548 |
| 1.01375 | 3.271465 |
| 1.021 | 3.269419 |
| 1.02829 | 3.26741 |
| 1.03564 | 3.265436 |
| 1.04304 | 3.263496 |
| 1.0505 | 3.261591 |
| 1.05801 | 3.259719 |
| 1.06557 | 3.257879 |
| 1.07318 | 3.256072 |
| 1.08085 | 3.254295 |
| 1.08858 | 3.25255 |
| 1.09636 | 3.250834 |
| 1.1042 | 3.249148 |
| 1.11209 | 3.247491 |
| 1.12004 | 3.245861 |
| 1.12804 | 3.24426 |
| 1.1361 | 3.242686 |
| 1.14422 | 3.241138 |
| 1.1524 | 3.239616 |
| 1.16064 | 3.23812 |
| 1.16893 | 3.236649 |
| 1.17729 | 3.235202 |
| 1.1857 | 3.23378 |
| 1.19418 | 3.232381 |
| 1.20271 | 3.231005 |
| 1.21131 | 3.229652 |
| 1.21997 | 3.228321 |
| 1.22868 | 3.227013 |
| 1.23747 | 3.225725 |
| 1.24631 | 3.224459 |
| 1.25522 | 3.223213 |
| 1.26419 | 3.221987 |
| 1.27322 | 3.220782 |
| 1.28232 | 3.219595 |
| 1.29149 | 3.218428 |
| 1.30072 | 3.21728 |
| 1.31002 | 3.21615 |
| 1.31938 | 3.215038 |
| 1.32881 | 3.213944 |
| 1.33831 | 3.212868 |
| 1.34787 | 3.211808 |
| 1.35751 | 3.210765 |
| 1.36721 | 3.209739 |
| 1.37698 | 3.208729 |
| 1.38682 | 3.207735 |
| 1.39673 | 3.206756 |
| 1.40672 | 3.205793 |
| 1.41677 | 3.204845 |
| 1.4269 | 3.203912 |
| 1.43709 | 3.202993 |
| 1.44736 | 3.202088 |
| 1.45771 | 3.201197 |
| 1.46813 | 3.200321 |
| 1.47862 | 3.199457 |
| 1.48919 | 3.198607 |
| 1.49983 | 3.19777 |
| 1.51055 | 3.196946 |
| 1.52135 | 3.196134 |
| 1.53222 | 3.195335 |
| 1.54317 | 3.194547 |
| 1.5542 | 3.193772 |
| 1.56531 | 3.193008 |
| 1.5765 | 3.192256 |
| 1.58776 | 3.191516 |
| 1.59911 | 3.190786 |
| 1.61054 | 3.190067 |
| 1.62205 | 3.189359 |
| 1.63365 | 3.188662 |
| 1.64532 | 3.187975 |
| 1.65708 | 3.187298 |
| 1.66892 | 3.186631 |
| 1.68085 | 3.185974 |
| 1.69287 | 3.185326 |
| 1.70497 | 3.184688 |
| 1.71715 | 3.18406 |
| 1.72942 | 3.18344 |
| 1.74178 | 3.18283 |
| 1.75423 | 3.182228 |
| 1.76677 | 3.181636 |
| 1.7794 | 3.181051 |
| 1.79212 | 3.180475 |
| 1.80492 | 3.179908 |
| 1.81782 | 3.179348 |
| 1.83082 | 3.178797 |
| 1.8439 | 3.178253 |
| 1.85708 | 3.177717 |
| 1.87035 | 3.177189 |
| 1.88372 | 3.176668 |
| 1.89719 | 3.176154 |
| 1.91074 | 3.175648 |
| 1.9244 | 3.175149 |
| 1.93816 | 3.174656 |
| 1.95201 | 3.174171 |
| 1.96596 | 3.173692 |
| 1.98001 | 3.17322 |
| 1.99416 | 3.172754 |
| 2.00841 | 3.172294 |
| 2.02277 | 3.171841 |
| 2.03723 | 3.171394 |
| 2.05179 | 3.170953 |
| 2.06645 | 3.170518 |
| 2.08122 | 3.170089 |
| 2.09609 | 3.169666 |
| 2.11108 | 3.169248 |
| 2.12616 | 3.168836 |
| 2.14136 | 3.168429 |
| 2.15666 | 3.168027 |
| 2.17208 | 3.167631 |
| 2.1876 | 3.16724 |
| 2.20324 | 3.166854 |
| 2.21899 | 3.166473 |
| 2.23484 | 3.166097 |
| 2.25082 | 3.165726 |
| 2.2669 | 3.165359 |
| 2.28311 | 3.164997 |
| 2.29942 | 3.164639 |
| 2.31586 | 3.164286 |
| 2.33241 | 3.163938 |
| 2.34908 | 3.163593 |
| 2.36587 | 3.163253 |
| 2.38278 | 3.162917 |
| 2.39981 | 3.162586 |
| 2.41696 | 3.162258 |
| 2.43424 | 3.161934 |
| 2.45163 | 3.161614 |
| 2.46916 | 3.161297 |
| 2.4868 | 3.160985 |
| 2.50458 | 3.160675 |
| 2.52248 | 3.16037 |
| 2.54051 | 3.160068 |
| 2.55866 | 3.159769 |
| 2.57695 | 3.159474 |
| 2.59537 | 3.159182 |
| 2.61392 | 3.158894 |
| 2.6326 | 3.158608 |
| 2.65142 | 3.158326 |
| 2.67037 | 3.158046 |
| 2.68945 | 3.15777 |
| 2.70867 | 3.157496 |
| 2.72803 | 3.157226 |
| 2.74753 | 3.156958 |
| 2.76717 | 3.156693 |
| 2.78695 | 3.15643 |
| 2.80686 | 3.15617 |
| 2.82693 | 3.155913 |
| 2.84713 | 3.155658 |
| 2.86748 | 3.155406 |
| 2.88797 | 3.155156 |
| 2.90861 | 3.154908 |
| 2.9294 | 3.154663 |
| 2.95034 | 3.15442 |
| 2.97143 | 3.154179 |
| 2.99266 | 3.15394 |
| 3.01405 | 3.153703 |
| 3.03559 | 3.153468 |
| 3.05729 | 3.153236 |
| 3.07914 | 3.153005 |
| 3.10115 | 3.152776 |
| 3.12331 | 3.152548 |
| 3.14564 | 3.152323 |
| 3.16812 | 3.152099 |
| 3.19076 | 3.151877 |
| 3.21357 | 3.151657 |
| 3.23653 | 3.151438 |
| 3.25967 | 3.15122 |
| 3.28296 | 3.151004 |
| 3.30643 | 3.15079 |
| 3.33006 | 3.150577 |
| 3.35386 | 3.150365 |
| 3.37783 | 3.150155 |
| 3.40197 | 3.149945 |
| 3.42629 | 3.149737 |
| 3.45078 | 3.14953 |
| 3.47544 | 3.149325 |
| 3.50028 | 3.14912 |
| 3.5253 | 3.148916 |
| 3.55049 | 3.148713 |
| 3.57587 | 3.148512 |
| 3.60142 | 3.148311 |
| 3.62716 | 3.14811 |
| 3.65309 | 3.147911 |
| 3.6792 | 3.147713 |
| 3.70549 | 3.147515 |
| 3.73198 | 3.147318 |
| 3.75865 | 3.147121 |
| 3.78551 | 3.146925 |
| 3.81257 | 3.14673 |
| 3.83982 | 3.146535 |
| 3.86726 | 3.14634 |
| 3.8949 | 3.146146 |
| 3.92274 | 3.145953 |
| 3.95078 | 3.145759 |
| 3.97901 | 3.145566 |
| 4.00745 | 3.145374 |
| 4.03609 | 3.145181 |
| 4.06494 | 3.144988 |
| 4.09399 | 3.144796 |
| 4.12325 | 3.144604 |
| 4.15272 | 3.144412 |
| 4.1824 | 3.144219 |
| 4.2123 | 3.144027 |
| 4.2424 | 3.143835 |
| 4.27272 | 3.143642 |
| 4.30326 | 3.14345 |
| 4.33402 | 3.143257 |
| 4.36499 | 3.143064 |
| 4.39619 | 3.14287 |
| 4.42761 | 3.142676 |
| 4.45926 | 3.142482 |
| 4.49113 | 3.142287 |
| 4.52323 | 3.142092 |
| 4.55556 | 3.141897 |
| 4.58812 | 3.1417 |
| 4.62091 | 3.141503 |
| 4.65393 | 3.141306 |
| 4.6872 | 3.141108 |
| 4.7207 | 3.140909 |
| 4.75444 | 3.140709 |
| 4.78842 | 3.140509 |
| 4.82264 | 3.140307 |
| 4.85711 | 3.140105 |
| 4.89182 | 3.139901 |
| 4.92679 | 3.139697 |
| 4.962 | 3.139492 |
| 4.99746 | 3.139285 |
| 5.03318 | 3.139077 |
| 5.06915 | 3.138869 |
| 5.10538 | 3.138658 |
| 5.14187 | 3.138447 |
| 5.17862 | 3.138234 |
| 5.21564 | 3.13802 |
| 5.25291 | 3.137804 |
| 5.29046 | 3.137587 |
| 5.32827 | 3.137368 |
| 5.36635 | 3.137148 |
| 5.4047 | 3.136926 |
| 5.44333 | 3.136702 |
| 5.48224 | 3.136477 |
| 5.52142 | 3.136249 |
| 5.56088 | 3.13602 |
| 5.60063 | 3.135789 |
| 5.64066 | 3.135556 |
| 5.68097 | 3.135321 |
| 5.72157 | 3.135084 |
| 5.76247 | 3.134844 |
| 5.80365 | 3.134603 |
| 5.84513 | 3.134359 |
| 5.88691 | 3.134113 |
| 5.92898 | 3.133864 |
| 5.97136 | 3.133613 |
| 6.01404 | 3.13336 |
| 6.05702 | 3.133104 |
| 6.10031 | 3.132845 |
| 6.14391 | 3.132583 |
| 6.18782 | 3.132319 |
| 6.23205 | 3.132052 |
| 6.27659 | 3.131782 |
| 6.32145 | 3.131509 |
| 6.36663 | 3.131233 |
| 6.41213 | 3.130954 |
| 6.45796 | 3.130672 |
| 6.50412 | 3.130386 |
| 6.5506 | 3.130097 |
| 6.59742 | 3.129805 |
| 6.64457 | 3.129509 |
| 6.69206 | 3.129209 |
| 6.73989 | 3.128906 |
| 6.78807 | 3.1286 |
| 6.83658 | 3.128289 |
| 6.88544 | 3.127974 |
| 6.93465 | 3.127656 |
| 6.98422 | 3.127333 |
| 7.03414 | 3.127007 |
| 7.08441 | 3.126676 |
| 7.13504 | 3.126341 |
| 7.18604 | 3.126001 |
| 7.2374 | 3.125657 |
| 7.28913 | 3.125308 |
| 7.34122 | 3.124954 |
| 7.39369 | 3.124596 |
| 7.44654 | 3.124233 |
| 7.49976 | 3.123864 |
| 7.55336 | 3.123491 |
| 7.60734 | 3.123112 |
| 7.66172 | 3.122728 |
| 7.71647 | 3.122339 |
| 7.77163 | 3.121944 |
| 7.82717 | 3.121543 |
| 7.88311 | 3.121137 |
| 7.93946 | 3.120724 |
| 7.9962 | 3.120306 |
| 8.05335 | 3.119881 |
| 8.11091 | 3.11945 |
| 8.16888 | 3.119012 |
| 8.22726 | 3.118568 |
| 8.28607 | 3.118118 |
| 8.34529 | 3.11766 |
| 8.40493 | 3.117196 |
| 8.465 | 3.116724 |
| 8.5255 | 3.116245 |
| 8.58644 | 3.115759 |
| 8.64781 | 3.115265 |
| 8.70961 | 3.114763 |
| 8.77186 | 3.114253 |
| 8.83456 | 3.113735 |
| 8.8977 | 3.113209 |
| 8.96129 | 3.112675 |
| 9.02534 | 3.112132 |
| 9.08985 | 3.11158 |
| 9.15481 | 3.111019 |
| 9.22024 | 3.110449 |
| 9.28614 | 3.109869 |
| 9.35251 | 3.10928 |
| 9.41936 | 3.108681 |
| 9.48668 | 3.108072 |
| 9.55448 | 3.107453 |
| 9.62277 | 3.106824 |
| 9.69155 | 3.106184 |
| 9.76081 | 3.105532 |
| 9.83057 | 3.10487 |
| 9.90084 | 3.104197 |
| 9.9716 | 3.103511 |
| 10.0429 | 3.102814 |
| 10.1146 | 3.102105 |
| 10.1869 | 3.101383 |
| 10.2597 | 3.100648 |
| 10.3331 | 3.099901 |
| 10.4069 | 3.09914 |
| 10.4813 | 3.098366 |
| 10.5562 | 3.097577 |
| 10.6317 | 3.096775 |
| 10.7077 | 3.095957 |
| 10.7842 | 3.095125 |
| 10.8613 | 3.094278 |
| 10.9389 | 3.093415 |
| 11.0171 | 3.092536 |
| 11.0958 | 3.091641 |
| 11.1751 | 3.090728 |
| 11.255 | 3.089799 |
| 11.3354 | 3.088852 |
| 11.4164 | 3.087887 |
| 11.498 | 3.086904 |
| 11.5802 | 3.085902 |
| 11.663 | 3.08488 |
| 11.7463 | 3.083839 |
| 11.8303 | 3.082777 |
| 11.9148 | 3.081694 |
| 12 | 3.08059 |
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
- —
Critical analysis of experimental data from multiple sources.