Optical constants
Refractive index of ZnGeP2 (Zinc germanium phosphide, ZGP)
Zelmon et al. 2001: n(o) 2–9 µm
- Data
- formula 2
- Range
- 2–9 µm
- Temperature
- 294 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
- 3.11886
- Extinction coefficient k
- 0
- Permittivity ε1
- 9.72729
- Permittivity ε2
- 0
- Absorption coefficient α
- 0 cm⁻¹
- Penetration depth δ = λ/(2πk)
- — nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.00607368 µm⁻¹
- Group index ng
- 3.14461
- Group velocity dispersion
- 188.344 fs²/mm
- Dispersion parameter D
- -19.7343 ps/(nm·km)
- Photon energy
- 0.292416 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): Zelmon et al. 2001: n(o) 2–9 µm
zngep2 = ls.fetch_refractiveindex("main", "ZnGeP2", "Zelmon-o", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(zngep2.range_nm) # (2000, 9000) nm
eps = zngep2.eps([4240]) # 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_082984b200cd/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/zelmon-2001-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=2000, stop_nm=9000, 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_082984b200cd/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 2.0 to 9.0 µm.
Coefficients as stored
| Ci | Value |
|---|---|
| C1 | 7.0409 |
| C2 | 1.68625 |
| C3 | 0.40824 |
| C4 | 1.288 |
| C5 | 611.05 |
Comments and conditions
Conditions
- temperature
- 294 K
- direction
- o
References
D. E. Zelmon, E. A. Hanning, P. G. Schunemann.
Refractive-index measurements and Sellmeier coefficients for zinc germanium phosphide from 2 to 9 µm with implications for phase matching in optical frequency-conversion devices.
J. Opt. Soc. Am. B 18, 1307-1310 (2001)
- doi:10.1364/josab.18.001307 Refractive-index measurements and Sellmeier coefficients for zinc germanium phosphide from 2 to 9 µm with implications for phase matching in optical frequency-conversion devices, Journal of the Optical Society of America B (2001)
Cite
David E. Zelmon, Elizabeth A. Hanning and Peter G. Schunemann. Refractive-index measurements and Sellmeier coefficients for zinc germanium phosphide from 2 to 9 µm with implications for phase matching in optical frequency-conversion devices. Journal of the Optical Society of America B, 18, 1307 (2001), doi:10.1364/josab.18.001307; 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 |
|---|---|
| 2 | 3.148066 |
| 2.00755 | 3.147802 |
| 2.01514 | 3.147539 |
| 2.02275 | 3.147279 |
| 2.03039 | 3.147021 |
| 2.03805 | 3.146765 |
| 2.04575 | 3.146511 |
| 2.05348 | 3.14626 |
| 2.06123 | 3.14601 |
| 2.06902 | 3.145763 |
| 2.07683 | 3.145517 |
| 2.08468 | 3.145274 |
| 2.09255 | 3.145033 |
| 2.10045 | 3.144793 |
| 2.10838 | 3.144556 |
| 2.11635 | 3.14432 |
| 2.12434 | 3.144087 |
| 2.13236 | 3.143855 |
| 2.14042 | 3.143625 |
| 2.1485 | 3.143397 |
| 2.15661 | 3.143171 |
| 2.16476 | 3.142947 |
| 2.17293 | 3.142724 |
| 2.18114 | 3.142503 |
| 2.18938 | 3.142284 |
| 2.19765 | 3.142067 |
| 2.20595 | 3.141851 |
| 2.21428 | 3.141637 |
| 2.22264 | 3.141425 |
| 2.23104 | 3.141215 |
| 2.23946 | 3.141006 |
| 2.24792 | 3.140798 |
| 2.25641 | 3.140593 |
| 2.26493 | 3.140389 |
| 2.27349 | 3.140186 |
| 2.28207 | 3.139985 |
| 2.29069 | 3.139785 |
| 2.29934 | 3.139588 |
| 2.30803 | 3.139391 |
| 2.31674 | 3.139196 |
| 2.32549 | 3.139003 |
| 2.33428 | 3.13881 |
| 2.34309 | 3.13862 |
| 2.35194 | 3.138431 |
| 2.36082 | 3.138243 |
| 2.36974 | 3.138056 |
| 2.37869 | 3.137871 |
| 2.38767 | 3.137688 |
| 2.39669 | 3.137505 |
| 2.40574 | 3.137324 |
| 2.41483 | 3.137145 |
| 2.42395 | 3.136966 |
| 2.4331 | 3.136789 |
| 2.44229 | 3.136613 |
| 2.45152 | 3.136439 |
| 2.46077 | 3.136265 |
| 2.47007 | 3.136093 |
| 2.4794 | 3.135922 |
| 2.48876 | 3.135752 |
| 2.49816 | 3.135584 |
| 2.5076 | 3.135416 |
| 2.51707 | 3.13525 |
| 2.52657 | 3.135085 |
| 2.53611 | 3.134921 |
| 2.54569 | 3.134758 |
| 2.55531 | 3.134597 |
| 2.56496 | 3.134436 |
| 2.57464 | 3.134276 |
| 2.58437 | 3.134118 |
| 2.59413 | 3.133961 |
| 2.60393 | 3.133804 |
| 2.61376 | 3.133649 |
| 2.62363 | 3.133495 |
| 2.63354 | 3.133341 |
| 2.64349 | 3.133189 |
| 2.65347 | 3.133038 |
| 2.66349 | 3.132887 |
| 2.67355 | 3.132738 |
| 2.68365 | 3.132589 |
| 2.69378 | 3.132442 |
| 2.70396 | 3.132295 |
| 2.71417 | 3.13215 |
| 2.72442 | 3.132005 |
| 2.73471 | 3.131861 |
| 2.74504 | 3.131718 |
| 2.75541 | 3.131576 |
| 2.76581 | 3.131435 |
| 2.77626 | 3.131294 |
| 2.78674 | 3.131155 |
| 2.79727 | 3.131016 |
| 2.80783 | 3.130878 |
| 2.81844 | 3.130741 |
| 2.82908 | 3.130605 |
| 2.83977 | 3.13047 |
| 2.85049 | 3.130335 |
| 2.86126 | 3.130201 |
| 2.87206 | 3.130068 |
| 2.88291 | 3.129935 |
| 2.8938 | 3.129804 |
| 2.90473 | 3.129673 |
| 2.9157 | 3.129543 |
| 2.92671 | 3.129413 |
| 2.93776 | 3.129285 |
| 2.94886 | 3.129156 |
| 2.95999 | 3.129029 |
| 2.97117 | 3.128902 |
| 2.98239 | 3.128776 |
| 2.99366 | 3.128651 |
| 3.00496 | 3.128526 |
| 3.01631 | 3.128402 |
| 3.02771 | 3.128279 |
| 3.03914 | 3.128156 |
| 3.05062 | 3.128034 |
| 3.06214 | 3.127912 |
| 3.0737 | 3.127791 |
| 3.08531 | 3.127671 |
| 3.09697 | 3.127551 |
| 3.10866 | 3.127432 |
| 3.1204 | 3.127313 |
| 3.13219 | 3.127195 |
| 3.14402 | 3.127077 |
| 3.15589 | 3.12696 |
| 3.16781 | 3.126844 |
| 3.17977 | 3.126728 |
| 3.19178 | 3.126613 |
| 3.20384 | 3.126498 |
| 3.21594 | 3.126383 |
| 3.22808 | 3.126269 |
| 3.24028 | 3.126156 |
| 3.25251 | 3.126043 |
| 3.2648 | 3.12593 |
| 3.27713 | 3.125818 |
| 3.2895 | 3.125707 |
| 3.30193 | 3.125595 |
| 3.3144 | 3.125485 |
| 3.32692 | 3.125375 |
| 3.33948 | 3.125265 |
| 3.35209 | 3.125155 |
| 3.36475 | 3.125046 |
| 3.37746 | 3.124938 |
| 3.39022 | 3.124829 |
| 3.40302 | 3.124722 |
| 3.41587 | 3.124614 |
| 3.42877 | 3.124507 |
| 3.44172 | 3.1244 |
| 3.45472 | 3.124294 |
| 3.46777 | 3.124188 |
| 3.48087 | 3.124082 |
| 3.49401 | 3.123977 |
| 3.50721 | 3.123872 |
| 3.52045 | 3.123767 |
| 3.53375 | 3.123663 |
| 3.5471 | 3.123559 |
| 3.56049 | 3.123455 |
| 3.57394 | 3.123352 |
| 3.58744 | 3.123248 |
| 3.60099 | 3.123146 |
| 3.61459 | 3.123043 |
| 3.62824 | 3.122941 |
| 3.64194 | 3.122839 |
| 3.65569 | 3.122737 |
| 3.6695 | 3.122635 |
| 3.68336 | 3.122534 |
| 3.69727 | 3.122433 |
| 3.71123 | 3.122332 |
| 3.72525 | 3.122231 |
| 3.73932 | 3.122131 |
| 3.75344 | 3.12203 |
| 3.76762 | 3.12193 |
| 3.78185 | 3.121831 |
| 3.79613 | 3.121731 |
| 3.81047 | 3.121631 |
| 3.82486 | 3.121532 |
| 3.8393 | 3.121433 |
| 3.8538 | 3.121334 |
| 3.86836 | 3.121235 |
| 3.88297 | 3.121136 |
| 3.89763 | 3.121038 |
| 3.91235 | 3.12094 |
| 3.92713 | 3.120841 |
| 3.94196 | 3.120743 |
| 3.95685 | 3.120645 |
| 3.97179 | 3.120547 |
| 3.98679 | 3.120449 |
| 4.00185 | 3.120352 |
| 4.01696 | 3.120254 |
| 4.03214 | 3.120156 |
| 4.04736 | 3.120059 |
| 4.06265 | 3.119961 |
| 4.07799 | 3.119864 |
| 4.09339 | 3.119767 |
| 4.10885 | 3.11967 |
| 4.12437 | 3.119572 |
| 4.13995 | 3.119475 |
| 4.15558 | 3.119378 |
| 4.17128 | 3.119281 |
| 4.18703 | 3.119184 |
| 4.20285 | 3.119087 |
| 4.21872 | 3.11899 |
| 4.23465 | 3.118893 |
| 4.25064 | 3.118796 |
| 4.2667 | 3.118699 |
| 4.28281 | 3.118601 |
| 4.29899 | 3.118504 |
| 4.31522 | 3.118407 |
| 4.33152 | 3.11831 |
| 4.34788 | 3.118213 |
| 4.3643 | 3.118115 |
| 4.38078 | 3.118018 |
| 4.39733 | 3.117921 |
| 4.41394 | 3.117823 |
| 4.43061 | 3.117725 |
| 4.44734 | 3.117628 |
| 4.46414 | 3.11753 |
| 4.481 | 3.117432 |
| 4.49792 | 3.117334 |
| 4.51491 | 3.117236 |
| 4.53196 | 3.117138 |
| 4.54907 | 3.11704 |
| 4.56626 | 3.116941 |
| 4.5835 | 3.116843 |
| 4.60081 | 3.116744 |
| 4.61819 | 3.116645 |
| 4.63563 | 3.116546 |
| 4.65314 | 3.116447 |
| 4.67071 | 3.116347 |
| 4.68835 | 3.116248 |
| 4.70606 | 3.116148 |
| 4.72383 | 3.116048 |
| 4.74167 | 3.115948 |
| 4.75958 | 3.115848 |
| 4.77755 | 3.115747 |
| 4.7956 | 3.115646 |
| 4.81371 | 3.115545 |
| 4.83189 | 3.115444 |
| 4.85014 | 3.115343 |
| 4.86846 | 3.115241 |
| 4.88684 | 3.115139 |
| 4.9053 | 3.115037 |
| 4.92383 | 3.114934 |
| 4.94242 | 3.114832 |
| 4.96109 | 3.114729 |
| 4.97982 | 3.114625 |
| 4.99863 | 3.114522 |
| 5.01751 | 3.114418 |
| 5.03646 | 3.114314 |
| 5.05548 | 3.114209 |
| 5.07457 | 3.114104 |
| 5.09374 | 3.113999 |
| 5.11298 | 3.113893 |
| 5.13229 | 3.113788 |
| 5.15167 | 3.113681 |
| 5.17113 | 3.113575 |
| 5.19066 | 3.113468 |
| 5.21026 | 3.113361 |
| 5.22994 | 3.113253 |
| 5.24969 | 3.113145 |
| 5.26952 | 3.113036 |
| 5.28942 | 3.112927 |
| 5.3094 | 3.112818 |
| 5.32945 | 3.112708 |
| 5.34958 | 3.112598 |
| 5.36978 | 3.112487 |
| 5.39006 | 3.112376 |
| 5.41042 | 3.112265 |
| 5.43085 | 3.112153 |
| 5.45136 | 3.11204 |
| 5.47195 | 3.111928 |
| 5.49262 | 3.111814 |
| 5.51336 | 3.1117 |
| 5.53418 | 3.111586 |
| 5.55508 | 3.111471 |
| 5.57606 | 3.111355 |
| 5.59712 | 3.11124 |
| 5.61826 | 3.111123 |
| 5.63948 | 3.111006 |
| 5.66078 | 3.110888 |
| 5.68216 | 3.11077 |
| 5.70362 | 3.110652 |
| 5.72516 | 3.110532 |
| 5.74678 | 3.110412 |
| 5.76849 | 3.110292 |
| 5.79027 | 3.110171 |
| 5.81214 | 3.110049 |
| 5.83409 | 3.109927 |
| 5.85613 | 3.109804 |
| 5.87824 | 3.10968 |
| 5.90044 | 3.109556 |
| 5.92273 | 3.109431 |
| 5.9451 | 3.109305 |
| 5.96755 | 3.109179 |
| 5.99009 | 3.109052 |
| 6.01271 | 3.108925 |
| 6.03542 | 3.108796 |
| 6.05821 | 3.108667 |
| 6.08109 | 3.108537 |
| 6.10406 | 3.108407 |
| 6.12711 | 3.108276 |
| 6.15025 | 3.108143 |
| 6.17348 | 3.108011 |
| 6.1968 | 3.107877 |
| 6.2202 | 3.107743 |
| 6.24369 | 3.107607 |
| 6.26727 | 3.107471 |
| 6.29094 | 3.107335 |
| 6.3147 | 3.107197 |
| 6.33855 | 3.107058 |
| 6.36249 | 3.106919 |
| 6.38652 | 3.106779 |
| 6.41064 | 3.106638 |
| 6.43485 | 3.106496 |
| 6.45915 | 3.106353 |
| 6.48355 | 3.106209 |
| 6.50803 | 3.106064 |
| 6.53261 | 3.105919 |
| 6.55729 | 3.105772 |
| 6.58205 | 3.105624 |
| 6.60691 | 3.105476 |
| 6.63186 | 3.105326 |
| 6.65691 | 3.105176 |
| 6.68205 | 3.105024 |
| 6.70729 | 3.104872 |
| 6.73262 | 3.104718 |
| 6.75804 | 3.104563 |
| 6.78357 | 3.104408 |
| 6.80919 | 3.104251 |
| 6.8349 | 3.104093 |
| 6.86072 | 3.103934 |
| 6.88663 | 3.103774 |
| 6.91264 | 3.103613 |
| 6.93875 | 3.103451 |
| 6.96495 | 3.103287 |
| 6.99126 | 3.103122 |
| 7.01766 | 3.102957 |
| 7.04416 | 3.102789 |
| 7.07077 | 3.102621 |
| 7.09747 | 3.102452 |
| 7.12428 | 3.102281 |
| 7.15118 | 3.102109 |
| 7.17819 | 3.101936 |
| 7.2053 | 3.101761 |
| 7.23251 | 3.101585 |
| 7.25983 | 3.101408 |
| 7.28725 | 3.10123 |
| 7.31477 | 3.10105 |
| 7.3424 | 3.100868 |
| 7.37013 | 3.100686 |
| 7.39796 | 3.100502 |
| 7.4259 | 3.100316 |
| 7.45395 | 3.100129 |
| 7.4821 | 3.099941 |
| 7.51036 | 3.099751 |
| 7.53872 | 3.09956 |
| 7.56719 | 3.099367 |
| 7.59577 | 3.099173 |
| 7.62446 | 3.098977 |
| 7.65325 | 3.09878 |
| 7.68216 | 3.098581 |
| 7.71117 | 3.09838 |
| 7.7403 | 3.098178 |
| 7.76953 | 3.097974 |
| 7.79887 | 3.097768 |
| 7.82833 | 3.097561 |
| 7.85789 | 3.097352 |
| 7.88757 | 3.097142 |
| 7.91736 | 3.096929 |
| 7.94726 | 3.096715 |
| 7.97727 | 3.096499 |
| 8.0074 | 3.096281 |
| 8.03764 | 3.096062 |
| 8.068 | 3.095841 |
| 8.09847 | 3.095617 |
| 8.12906 | 3.095392 |
| 8.15976 | 3.095165 |
| 8.19058 | 3.094936 |
| 8.22151 | 3.094705 |
| 8.25256 | 3.094472 |
| 8.28373 | 3.094237 |
| 8.31501 | 3.094 |
| 8.34642 | 3.093761 |
| 8.37794 | 3.09352 |
| 8.40958 | 3.093277 |
| 8.44134 | 3.093031 |
| 8.47322 | 3.092784 |
| 8.50522 | 3.092534 |
| 8.53734 | 3.092282 |
| 8.56959 | 3.092028 |
| 8.60195 | 3.091771 |
| 8.63444 | 3.091512 |
| 8.66705 | 3.091251 |
| 8.69978 | 3.090988 |
| 8.73264 | 3.090722 |
| 8.76562 | 3.090454 |
| 8.79873 | 3.090183 |
| 8.83196 | 3.08991 |
| 8.86531 | 3.089634 |
| 8.89879 | 3.089356 |
| 8.9324 | 3.089075 |
| 8.96614 | 3.088791 |
| 9 | 3.088505 |
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
- —
Ordinary ray (o); 21-22 °C.