Optical constants
Refractive index of ZnGeP2 (Zinc germanium phosphide, ZGP)
Ghosh 1998: n(o) 0.7–12 µm; 250 K
- Data
- formula 2
- Range
- 0.7–12 µm
- Temperature
- 250 K
- Optical axis
- o
- Licence
- CC0-1.0
Uniaxial crystal, axes: oe
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 3.12403
- Extinction coefficient k
- 0
- Permittivity ε1
- 9.75956
- Permittivity ε2
- 0
- Absorption coefficient α
- 0 cm⁻¹
- Penetration depth δ = λ/(2πk)
- — nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.0115497 µm⁻¹
- Group index ng
- 3.15752
- Group velocity dispersion
- 386.014 fs²/mm
- Dispersion parameter D
- -86.4584 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(o) 0.7–12 µm; 250 K
zngep2 = ls.fetch_refractiveindex("main", "ZnGeP2", "Ghosh-250K-o", 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_bc08f7fc68df/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-1998-250k-o).
# ... 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_bc08f7fc68df/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 | 3.58457517 |
| C2 | 5.11280186 |
| C3 | 0.13378216 |
| C4 | 2.16914685 |
| C5 | 900.0 |
Comments and conditions
Conditions
- temperature
- 250 K
- direction
- o
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 | 3.40828 |
| 0.705003 | 3.402822 |
| 0.710042 | 3.397489 |
| 0.715117 | 3.392277 |
| 0.720228 | 3.387182 |
| 0.725375 | 3.382202 |
| 0.73056 | 3.377332 |
| 0.735781 | 3.37257 |
| 0.74104 | 3.367912 |
| 0.746336 | 3.363355 |
| 0.75167 | 3.358898 |
| 0.757043 | 3.354536 |
| 0.762453 | 3.350267 |
| 0.767903 | 3.346089 |
| 0.773391 | 3.341999 |
| 0.778919 | 3.337995 |
| 0.784486 | 3.334075 |
| 0.790093 | 3.330236 |
| 0.79574 | 3.326476 |
| 0.801427 | 3.322793 |
| 0.807155 | 3.319186 |
| 0.812924 | 3.315651 |
| 0.818734 | 3.312188 |
| 0.824585 | 3.308795 |
| 0.830479 | 3.305469 |
| 0.836414 | 3.302209 |
| 0.842392 | 3.299014 |
| 0.848413 | 3.295881 |
| 0.854477 | 3.29281 |
| 0.860584 | 3.289799 |
| 0.866735 | 3.286846 |
| 0.87293 | 3.28395 |
| 0.879169 | 3.281109 |
| 0.885452 | 3.278323 |
| 0.891781 | 3.27559 |
| 0.898154 | 3.272909 |
| 0.904574 | 3.270278 |
| 0.911039 | 3.267696 |
| 0.91755 | 3.265163 |
| 0.924108 | 3.262677 |
| 0.930713 | 3.260238 |
| 0.937365 | 3.257843 |
| 0.944064 | 3.255492 |
| 0.950812 | 3.253184 |
| 0.957607 | 3.250919 |
| 0.964451 | 3.248695 |
| 0.971345 | 3.246511 |
| 0.978287 | 3.244366 |
| 0.985279 | 3.24226 |
| 0.992321 | 3.240191 |
| 0.999413 | 3.23816 |
| 1.00656 | 3.236165 |
| 1.01375 | 3.234205 |
| 1.021 | 3.232279 |
| 1.02829 | 3.230388 |
| 1.03564 | 3.228529 |
| 1.04304 | 3.226703 |
| 1.0505 | 3.224909 |
| 1.05801 | 3.223146 |
| 1.06557 | 3.221414 |
| 1.07318 | 3.219712 |
| 1.08085 | 3.218038 |
| 1.08858 | 3.216394 |
| 1.09636 | 3.214777 |
| 1.1042 | 3.213188 |
| 1.11209 | 3.211626 |
| 1.12004 | 3.210091 |
| 1.12804 | 3.208581 |
| 1.1361 | 3.207097 |
| 1.14422 | 3.205638 |
| 1.1524 | 3.204203 |
| 1.16064 | 3.202792 |
| 1.16893 | 3.201405 |
| 1.17729 | 3.200041 |
| 1.1857 | 3.198699 |
| 1.19418 | 3.197379 |
| 1.20271 | 3.196081 |
| 1.21131 | 3.194805 |
| 1.21997 | 3.193549 |
| 1.22868 | 3.192314 |
| 1.23747 | 3.191099 |
| 1.24631 | 3.189904 |
| 1.25522 | 3.188728 |
| 1.26419 | 3.187571 |
| 1.27322 | 3.186432 |
| 1.28232 | 3.185312 |
| 1.29149 | 3.18421 |
| 1.30072 | 3.183126 |
| 1.31002 | 3.182059 |
| 1.31938 | 3.181009 |
| 1.32881 | 3.179975 |
| 1.33831 | 3.178958 |
| 1.34787 | 3.177957 |
| 1.35751 | 3.176972 |
| 1.36721 | 3.176003 |
| 1.37698 | 3.175048 |
| 1.38682 | 3.174108 |
| 1.39673 | 3.173184 |
| 1.40672 | 3.172273 |
| 1.41677 | 3.171377 |
| 1.4269 | 3.170494 |
| 1.43709 | 3.169626 |
| 1.44736 | 3.16877 |
| 1.45771 | 3.167928 |
| 1.46813 | 3.167099 |
| 1.47862 | 3.166282 |
| 1.48919 | 3.165478 |
| 1.49983 | 3.164686 |
| 1.51055 | 3.163906 |
| 1.52135 | 3.163138 |
| 1.53222 | 3.162382 |
| 1.54317 | 3.161637 |
| 1.5542 | 3.160903 |
| 1.56531 | 3.16018 |
| 1.5765 | 3.159469 |
| 1.58776 | 3.158767 |
| 1.59911 | 3.158077 |
| 1.61054 | 3.157396 |
| 1.62205 | 3.156726 |
| 1.63365 | 3.156065 |
| 1.64532 | 3.155414 |
| 1.65708 | 3.154773 |
| 1.66892 | 3.154141 |
| 1.68085 | 3.153519 |
| 1.69287 | 3.152906 |
| 1.70497 | 3.152301 |
| 1.71715 | 3.151705 |
| 1.72942 | 3.151118 |
| 1.74178 | 3.15054 |
| 1.75423 | 3.149969 |
| 1.76677 | 3.149407 |
| 1.7794 | 3.148853 |
| 1.79212 | 3.148307 |
| 1.80492 | 3.147769 |
| 1.81782 | 3.147238 |
| 1.83082 | 3.146715 |
| 1.8439 | 3.146199 |
| 1.85708 | 3.145691 |
| 1.87035 | 3.145189 |
| 1.88372 | 3.144695 |
| 1.89719 | 3.144207 |
| 1.91074 | 3.143727 |
| 1.9244 | 3.143253 |
| 1.93816 | 3.142785 |
| 1.95201 | 3.142324 |
| 1.96596 | 3.141869 |
| 1.98001 | 3.14142 |
| 1.99416 | 3.140978 |
| 2.00841 | 3.140541 |
| 2.02277 | 3.14011 |
| 2.03723 | 3.139686 |
| 2.05179 | 3.139266 |
| 2.06645 | 3.138853 |
| 2.08122 | 3.138445 |
| 2.09609 | 3.138042 |
| 2.11108 | 3.137644 |
| 2.12616 | 3.137252 |
| 2.14136 | 3.136865 |
| 2.15666 | 3.136483 |
| 2.17208 | 3.136105 |
| 2.1876 | 3.135733 |
| 2.20324 | 3.135365 |
| 2.21899 | 3.135002 |
| 2.23484 | 3.134644 |
| 2.25082 | 3.13429 |
| 2.2669 | 3.13394 |
| 2.28311 | 3.133595 |
| 2.29942 | 3.133254 |
| 2.31586 | 3.132918 |
| 2.33241 | 3.132585 |
| 2.34908 | 3.132256 |
| 2.36587 | 3.131932 |
| 2.38278 | 3.131611 |
| 2.39981 | 3.131294 |
| 2.41696 | 3.130981 |
| 2.43424 | 3.130671 |
| 2.45163 | 3.130365 |
| 2.46916 | 3.130063 |
| 2.4868 | 3.129763 |
| 2.50458 | 3.129468 |
| 2.52248 | 3.129176 |
| 2.54051 | 3.128886 |
| 2.55866 | 3.128601 |
| 2.57695 | 3.128318 |
| 2.59537 | 3.128038 |
| 2.61392 | 3.127761 |
| 2.6326 | 3.127488 |
| 2.65142 | 3.127217 |
| 2.67037 | 3.126949 |
| 2.68945 | 3.126683 |
| 2.70867 | 3.126421 |
| 2.72803 | 3.126161 |
| 2.74753 | 3.125904 |
| 2.76717 | 3.125649 |
| 2.78695 | 3.125396 |
| 2.80686 | 3.125146 |
| 2.82693 | 3.124899 |
| 2.84713 | 3.124653 |
| 2.86748 | 3.12441 |
| 2.88797 | 3.124169 |
| 2.90861 | 3.123931 |
| 2.9294 | 3.123694 |
| 2.95034 | 3.12346 |
| 2.97143 | 3.123227 |
| 2.99266 | 3.122996 |
| 3.01405 | 3.122768 |
| 3.03559 | 3.122541 |
| 3.05729 | 3.122315 |
| 3.07914 | 3.122092 |
| 3.10115 | 3.12187 |
| 3.12331 | 3.12165 |
| 3.14564 | 3.121432 |
| 3.16812 | 3.121215 |
| 3.19076 | 3.120999 |
| 3.21357 | 3.120785 |
| 3.23653 | 3.120573 |
| 3.25967 | 3.120362 |
| 3.28296 | 3.120152 |
| 3.30643 | 3.119943 |
| 3.33006 | 3.119736 |
| 3.35386 | 3.11953 |
| 3.37783 | 3.119324 |
| 3.40197 | 3.11912 |
| 3.42629 | 3.118917 |
| 3.45078 | 3.118715 |
| 3.47544 | 3.118514 |
| 3.50028 | 3.118314 |
| 3.5253 | 3.118115 |
| 3.55049 | 3.117917 |
| 3.57587 | 3.117719 |
| 3.60142 | 3.117522 |
| 3.62716 | 3.117326 |
| 3.65309 | 3.117131 |
| 3.6792 | 3.116936 |
| 3.70549 | 3.116741 |
| 3.73198 | 3.116548 |
| 3.75865 | 3.116354 |
| 3.78551 | 3.116161 |
| 3.81257 | 3.115969 |
| 3.83982 | 3.115777 |
| 3.86726 | 3.115585 |
| 3.8949 | 3.115394 |
| 3.92274 | 3.115202 |
| 3.95078 | 3.115011 |
| 3.97901 | 3.11482 |
| 4.00745 | 3.114629 |
| 4.03609 | 3.114439 |
| 4.06494 | 3.114248 |
| 4.09399 | 3.114057 |
| 4.12325 | 3.113866 |
| 4.15272 | 3.113675 |
| 4.1824 | 3.113484 |
| 4.2123 | 3.113293 |
| 4.2424 | 3.113102 |
| 4.27272 | 3.11291 |
| 4.30326 | 3.112718 |
| 4.33402 | 3.112526 |
| 4.36499 | 3.112333 |
| 4.39619 | 3.11214 |
| 4.42761 | 3.111946 |
| 4.45926 | 3.111752 |
| 4.49113 | 3.111557 |
| 4.52323 | 3.111362 |
| 4.55556 | 3.111166 |
| 4.58812 | 3.110969 |
| 4.62091 | 3.110771 |
| 4.65393 | 3.110573 |
| 4.6872 | 3.110374 |
| 4.7207 | 3.110174 |
| 4.75444 | 3.109973 |
| 4.78842 | 3.109771 |
| 4.82264 | 3.109568 |
| 4.85711 | 3.109364 |
| 4.89182 | 3.109159 |
| 4.92679 | 3.108953 |
| 4.962 | 3.108746 |
| 4.99746 | 3.108537 |
| 5.03318 | 3.108327 |
| 5.06915 | 3.108116 |
| 5.10538 | 3.107903 |
| 5.14187 | 3.107689 |
| 5.17862 | 3.107473 |
| 5.21564 | 3.107256 |
| 5.25291 | 3.107037 |
| 5.29046 | 3.106817 |
| 5.32827 | 3.106595 |
| 5.36635 | 3.106371 |
| 5.4047 | 3.106145 |
| 5.44333 | 3.105917 |
| 5.48224 | 3.105688 |
| 5.52142 | 3.105456 |
| 5.56088 | 3.105223 |
| 5.60063 | 3.104987 |
| 5.64066 | 3.10475 |
| 5.68097 | 3.10451 |
| 5.72157 | 3.104268 |
| 5.76247 | 3.104023 |
| 5.80365 | 3.103777 |
| 5.84513 | 3.103527 |
| 5.88691 | 3.103276 |
| 5.92898 | 3.103021 |
| 5.97136 | 3.102764 |
| 6.01404 | 3.102505 |
| 6.05702 | 3.102243 |
| 6.10031 | 3.101977 |
| 6.14391 | 3.101709 |
| 6.18782 | 3.101438 |
| 6.23205 | 3.101164 |
| 6.27659 | 3.100887 |
| 6.32145 | 3.100607 |
| 6.36663 | 3.100324 |
| 6.41213 | 3.100037 |
| 6.45796 | 3.099747 |
| 6.50412 | 3.099453 |
| 6.5506 | 3.099156 |
| 6.59742 | 3.098855 |
| 6.64457 | 3.098551 |
| 6.69206 | 3.098243 |
| 6.73989 | 3.097931 |
| 6.78807 | 3.097615 |
| 6.83658 | 3.097295 |
| 6.88544 | 3.096971 |
| 6.93465 | 3.096642 |
| 6.98422 | 3.09631 |
| 7.03414 | 3.095973 |
| 7.08441 | 3.095632 |
| 7.13504 | 3.095286 |
| 7.18604 | 3.094935 |
| 7.2374 | 3.09458 |
| 7.28913 | 3.094219 |
| 7.34122 | 3.093854 |
| 7.39369 | 3.093484 |
| 7.44654 | 3.093109 |
| 7.49976 | 3.092728 |
| 7.55336 | 3.092342 |
| 7.60734 | 3.091951 |
| 7.66172 | 3.091553 |
| 7.71647 | 3.091151 |
| 7.77163 | 3.090742 |
| 7.82717 | 3.090327 |
| 7.88311 | 3.089907 |
| 7.93946 | 3.08948 |
| 7.9962 | 3.089046 |
| 8.05335 | 3.088607 |
| 8.11091 | 3.08816 |
| 8.16888 | 3.087707 |
| 8.22726 | 3.087247 |
| 8.28607 | 3.08678 |
| 8.34529 | 3.086306 |
| 8.40493 | 3.085825 |
| 8.465 | 3.085336 |
| 8.5255 | 3.084839 |
| 8.58644 | 3.084335 |
| 8.64781 | 3.083823 |
| 8.70961 | 3.083302 |
| 8.77186 | 3.082774 |
| 8.83456 | 3.082236 |
| 8.8977 | 3.081691 |
| 8.96129 | 3.081136 |
| 9.02534 | 3.080572 |
| 9.08985 | 3.08 |
| 9.15481 | 3.079417 |
| 9.22024 | 3.078826 |
| 9.28614 | 3.078224 |
| 9.35251 | 3.077612 |
| 9.41936 | 3.076991 |
| 9.48668 | 3.076358 |
| 9.55448 | 3.075715 |
| 9.62277 | 3.075062 |
| 9.69155 | 3.074397 |
| 9.76081 | 3.07372 |
| 9.83057 | 3.073032 |
| 9.90084 | 3.072332 |
| 9.9716 | 3.07162 |
| 10.0429 | 3.070896 |
| 10.1146 | 3.070159 |
| 10.1869 | 3.069408 |
| 10.2597 | 3.068645 |
| 10.3331 | 3.067868 |
| 10.4069 | 3.067077 |
| 10.4813 | 3.066272 |
| 10.5562 | 3.065452 |
| 10.6317 | 3.064618 |
| 10.7077 | 3.063768 |
| 10.7842 | 3.062902 |
| 10.8613 | 3.062021 |
| 10.9389 | 3.061124 |
| 11.0171 | 3.060209 |
| 11.0958 | 3.059278 |
| 11.1751 | 3.058329 |
| 11.255 | 3.057362 |
| 11.3354 | 3.056377 |
| 11.4164 | 3.055373 |
| 11.498 | 3.05435 |
| 11.5802 | 3.053307 |
| 11.663 | 3.052244 |
| 11.7463 | 3.051161 |
| 11.8303 | 3.050056 |
| 11.9148 | 3.048929 |
| 12 | 3.04778 |
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.