Optical constants
Refractive index of ZnGeP2 (Zinc germanium phosphide, ZGP)
Zelmon et al. 2001: n(e) 2–9 µm
- Data
- formula 2
- Range
- 2–9 µm
- Temperature
- 294 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
- 3.15706
- Extinction coefficient k
- 0
- Permittivity ε1
- 9.96702
- Permittivity ε2
- 0
- Absorption coefficient α
- 0 cm⁻¹
- Penetration depth δ = λ/(2πk)
- — nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.0060754 µm⁻¹
- Group index ng
- 3.18282
- Group velocity dispersion
- 229.624 fs²/mm
- Dispersion parameter D
- -24.0595 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(e) 2–9 µm
zngep2 = ls.fetch_refractiveindex("main", "ZnGeP2", "Zelmon-e", 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_b16f04f77e63/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-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=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_b16f04f77e63/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 | 7.0929 |
| C2 | 1.8649 |
| C3 | 0.41468 |
| C4 | 0.84052 |
| C5 | 452.05 |
Comments and conditions
Conditions
- temperature
- 294 K
- direction
- e
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 | 3.188415 |
| 2.00755 | 3.188123 |
| 2.01514 | 3.187833 |
| 2.02275 | 3.187546 |
| 2.03039 | 3.187261 |
| 2.03805 | 3.186979 |
| 2.04575 | 3.186699 |
| 2.05348 | 3.186422 |
| 2.06123 | 3.186147 |
| 2.06902 | 3.185874 |
| 2.07683 | 3.185603 |
| 2.08468 | 3.185335 |
| 2.09255 | 3.185069 |
| 2.10045 | 3.184805 |
| 2.10838 | 3.184544 |
| 2.11635 | 3.184284 |
| 2.12434 | 3.184027 |
| 2.13236 | 3.183772 |
| 2.14042 | 3.183519 |
| 2.1485 | 3.183268 |
| 2.15661 | 3.183019 |
| 2.16476 | 3.182773 |
| 2.17293 | 3.182528 |
| 2.18114 | 3.182285 |
| 2.18938 | 3.182044 |
| 2.19765 | 3.181805 |
| 2.20595 | 3.181568 |
| 2.21428 | 3.181333 |
| 2.22264 | 3.1811 |
| 2.23104 | 3.180869 |
| 2.23946 | 3.18064 |
| 2.24792 | 3.180412 |
| 2.25641 | 3.180186 |
| 2.26493 | 3.179962 |
| 2.27349 | 3.17974 |
| 2.28207 | 3.17952 |
| 2.29069 | 3.179301 |
| 2.29934 | 3.179084 |
| 2.30803 | 3.178869 |
| 2.31674 | 3.178655 |
| 2.32549 | 3.178443 |
| 2.33428 | 3.178233 |
| 2.34309 | 3.178024 |
| 2.35194 | 3.177817 |
| 2.36082 | 3.177611 |
| 2.36974 | 3.177407 |
| 2.37869 | 3.177205 |
| 2.38767 | 3.177004 |
| 2.39669 | 3.176805 |
| 2.40574 | 3.176607 |
| 2.41483 | 3.176411 |
| 2.42395 | 3.176216 |
| 2.4331 | 3.176022 |
| 2.44229 | 3.17583 |
| 2.45152 | 3.17564 |
| 2.46077 | 3.175451 |
| 2.47007 | 3.175263 |
| 2.4794 | 3.175076 |
| 2.48876 | 3.174891 |
| 2.49816 | 3.174708 |
| 2.5076 | 3.174525 |
| 2.51707 | 3.174344 |
| 2.52657 | 3.174165 |
| 2.53611 | 3.173986 |
| 2.54569 | 3.173809 |
| 2.55531 | 3.173633 |
| 2.56496 | 3.173459 |
| 2.57464 | 3.173285 |
| 2.58437 | 3.173113 |
| 2.59413 | 3.172942 |
| 2.60393 | 3.172772 |
| 2.61376 | 3.172604 |
| 2.62363 | 3.172436 |
| 2.63354 | 3.17227 |
| 2.64349 | 3.172105 |
| 2.65347 | 3.171941 |
| 2.66349 | 3.171778 |
| 2.67355 | 3.171616 |
| 2.68365 | 3.171456 |
| 2.69378 | 3.171296 |
| 2.70396 | 3.171138 |
| 2.71417 | 3.17098 |
| 2.72442 | 3.170824 |
| 2.73471 | 3.170668 |
| 2.74504 | 3.170514 |
| 2.75541 | 3.17036 |
| 2.76581 | 3.170208 |
| 2.77626 | 3.170057 |
| 2.78674 | 3.169906 |
| 2.79727 | 3.169757 |
| 2.80783 | 3.169608 |
| 2.81844 | 3.169461 |
| 2.82908 | 3.169314 |
| 2.83977 | 3.169168 |
| 2.85049 | 3.169024 |
| 2.86126 | 3.16888 |
| 2.87206 | 3.168737 |
| 2.88291 | 3.168595 |
| 2.8938 | 3.168453 |
| 2.90473 | 3.168313 |
| 2.9157 | 3.168173 |
| 2.92671 | 3.168035 |
| 2.93776 | 3.167897 |
| 2.94886 | 3.16776 |
| 2.95999 | 3.167623 |
| 2.97117 | 3.167488 |
| 2.98239 | 3.167353 |
| 2.99366 | 3.167219 |
| 3.00496 | 3.167086 |
| 3.01631 | 3.166953 |
| 3.02771 | 3.166822 |
| 3.03914 | 3.166691 |
| 3.05062 | 3.166561 |
| 3.06214 | 3.166431 |
| 3.0737 | 3.166302 |
| 3.08531 | 3.166174 |
| 3.09697 | 3.166047 |
| 3.10866 | 3.16592 |
| 3.1204 | 3.165794 |
| 3.13219 | 3.165669 |
| 3.14402 | 3.165544 |
| 3.15589 | 3.16542 |
| 3.16781 | 3.165297 |
| 3.17977 | 3.165174 |
| 3.19178 | 3.165052 |
| 3.20384 | 3.16493 |
| 3.21594 | 3.164809 |
| 3.22808 | 3.164689 |
| 3.24028 | 3.164569 |
| 3.25251 | 3.16445 |
| 3.2648 | 3.164331 |
| 3.27713 | 3.164213 |
| 3.2895 | 3.164096 |
| 3.30193 | 3.163979 |
| 3.3144 | 3.163862 |
| 3.32692 | 3.163747 |
| 3.33948 | 3.163631 |
| 3.35209 | 3.163516 |
| 3.36475 | 3.163402 |
| 3.37746 | 3.163288 |
| 3.39022 | 3.163175 |
| 3.40302 | 3.163062 |
| 3.41587 | 3.16295 |
| 3.42877 | 3.162838 |
| 3.44172 | 3.162726 |
| 3.45472 | 3.162615 |
| 3.46777 | 3.162505 |
| 3.48087 | 3.162394 |
| 3.49401 | 3.162285 |
| 3.50721 | 3.162175 |
| 3.52045 | 3.162066 |
| 3.53375 | 3.161958 |
| 3.5471 | 3.16185 |
| 3.56049 | 3.161742 |
| 3.57394 | 3.161635 |
| 3.58744 | 3.161528 |
| 3.60099 | 3.161422 |
| 3.61459 | 3.161315 |
| 3.62824 | 3.16121 |
| 3.64194 | 3.161104 |
| 3.65569 | 3.160999 |
| 3.6695 | 3.160894 |
| 3.68336 | 3.16079 |
| 3.69727 | 3.160686 |
| 3.71123 | 3.160582 |
| 3.72525 | 3.160478 |
| 3.73932 | 3.160375 |
| 3.75344 | 3.160272 |
| 3.76762 | 3.160169 |
| 3.78185 | 3.160067 |
| 3.79613 | 3.159965 |
| 3.81047 | 3.159863 |
| 3.82486 | 3.159761 |
| 3.8393 | 3.15966 |
| 3.8538 | 3.159559 |
| 3.86836 | 3.159458 |
| 3.88297 | 3.159358 |
| 3.89763 | 3.159257 |
| 3.91235 | 3.159157 |
| 3.92713 | 3.159057 |
| 3.94196 | 3.158957 |
| 3.95685 | 3.158858 |
| 3.97179 | 3.158758 |
| 3.98679 | 3.158659 |
| 4.00185 | 3.15856 |
| 4.01696 | 3.158461 |
| 4.03214 | 3.158363 |
| 4.04736 | 3.158264 |
| 4.06265 | 3.158166 |
| 4.07799 | 3.158067 |
| 4.09339 | 3.157969 |
| 4.10885 | 3.157871 |
| 4.12437 | 3.157773 |
| 4.13995 | 3.157676 |
| 4.15558 | 3.157578 |
| 4.17128 | 3.157481 |
| 4.18703 | 3.157383 |
| 4.20285 | 3.157286 |
| 4.21872 | 3.157189 |
| 4.23465 | 3.157091 |
| 4.25064 | 3.156994 |
| 4.2667 | 3.156897 |
| 4.28281 | 3.1568 |
| 4.29899 | 3.156703 |
| 4.31522 | 3.156607 |
| 4.33152 | 3.15651 |
| 4.34788 | 3.156413 |
| 4.3643 | 3.156316 |
| 4.38078 | 3.156219 |
| 4.39733 | 3.156123 |
| 4.41394 | 3.156026 |
| 4.43061 | 3.155929 |
| 4.44734 | 3.155832 |
| 4.46414 | 3.155736 |
| 4.481 | 3.155639 |
| 4.49792 | 3.155542 |
| 4.51491 | 3.155445 |
| 4.53196 | 3.155348 |
| 4.54907 | 3.155251 |
| 4.56626 | 3.155154 |
| 4.5835 | 3.155057 |
| 4.60081 | 3.15496 |
| 4.61819 | 3.154863 |
| 4.63563 | 3.154766 |
| 4.65314 | 3.154668 |
| 4.67071 | 3.154571 |
| 4.68835 | 3.154473 |
| 4.70606 | 3.154375 |
| 4.72383 | 3.154278 |
| 4.74167 | 3.15418 |
| 4.75958 | 3.154082 |
| 4.77755 | 3.153983 |
| 4.7956 | 3.153885 |
| 4.81371 | 3.153787 |
| 4.83189 | 3.153688 |
| 4.85014 | 3.153589 |
| 4.86846 | 3.15349 |
| 4.88684 | 3.153391 |
| 4.9053 | 3.153292 |
| 4.92383 | 3.153192 |
| 4.94242 | 3.153092 |
| 4.96109 | 3.152992 |
| 4.97982 | 3.152892 |
| 4.99863 | 3.152792 |
| 5.01751 | 3.152691 |
| 5.03646 | 3.15259 |
| 5.05548 | 3.152489 |
| 5.07457 | 3.152388 |
| 5.09374 | 3.152286 |
| 5.11298 | 3.152184 |
| 5.13229 | 3.152082 |
| 5.15167 | 3.15198 |
| 5.17113 | 3.151877 |
| 5.19066 | 3.151774 |
| 5.21026 | 3.151671 |
| 5.22994 | 3.151567 |
| 5.24969 | 3.151463 |
| 5.26952 | 3.151359 |
| 5.28942 | 3.151254 |
| 5.3094 | 3.151149 |
| 5.32945 | 3.151044 |
| 5.34958 | 3.150938 |
| 5.36978 | 3.150832 |
| 5.39006 | 3.150726 |
| 5.41042 | 3.150619 |
| 5.43085 | 3.150512 |
| 5.45136 | 3.150404 |
| 5.47195 | 3.150296 |
| 5.49262 | 3.150188 |
| 5.51336 | 3.150079 |
| 5.53418 | 3.14997 |
| 5.55508 | 3.14986 |
| 5.57606 | 3.14975 |
| 5.59712 | 3.14964 |
| 5.61826 | 3.149529 |
| 5.63948 | 3.149417 |
| 5.66078 | 3.149305 |
| 5.68216 | 3.149192 |
| 5.70362 | 3.149079 |
| 5.72516 | 3.148966 |
| 5.74678 | 3.148852 |
| 5.76849 | 3.148737 |
| 5.79027 | 3.148622 |
| 5.81214 | 3.148507 |
| 5.83409 | 3.14839 |
| 5.85613 | 3.148274 |
| 5.87824 | 3.148156 |
| 5.90044 | 3.148038 |
| 5.92273 | 3.14792 |
| 5.9451 | 3.147801 |
| 5.96755 | 3.147681 |
| 5.99009 | 3.14756 |
| 6.01271 | 3.147439 |
| 6.03542 | 3.147318 |
| 6.05821 | 3.147196 |
| 6.08109 | 3.147073 |
| 6.10406 | 3.146949 |
| 6.12711 | 3.146825 |
| 6.15025 | 3.1467 |
| 6.17348 | 3.146574 |
| 6.1968 | 3.146447 |
| 6.2202 | 3.14632 |
| 6.24369 | 3.146192 |
| 6.26727 | 3.146064 |
| 6.29094 | 3.145934 |
| 6.3147 | 3.145804 |
| 6.33855 | 3.145673 |
| 6.36249 | 3.145541 |
| 6.38652 | 3.145409 |
| 6.41064 | 3.145275 |
| 6.43485 | 3.145141 |
| 6.45915 | 3.145006 |
| 6.48355 | 3.14487 |
| 6.50803 | 3.144733 |
| 6.53261 | 3.144595 |
| 6.55729 | 3.144457 |
| 6.58205 | 3.144317 |
| 6.60691 | 3.144177 |
| 6.63186 | 3.144036 |
| 6.65691 | 3.143893 |
| 6.68205 | 3.14375 |
| 6.70729 | 3.143606 |
| 6.73262 | 3.143461 |
| 6.75804 | 3.143314 |
| 6.78357 | 3.143167 |
| 6.80919 | 3.143019 |
| 6.8349 | 3.14287 |
| 6.86072 | 3.142719 |
| 6.88663 | 3.142568 |
| 6.91264 | 3.142416 |
| 6.93875 | 3.142262 |
| 6.96495 | 3.142107 |
| 6.99126 | 3.141951 |
| 7.01766 | 3.141794 |
| 7.04416 | 3.141636 |
| 7.07077 | 3.141477 |
| 7.09747 | 3.141317 |
| 7.12428 | 3.141155 |
| 7.15118 | 3.140992 |
| 7.17819 | 3.140828 |
| 7.2053 | 3.140662 |
| 7.23251 | 3.140496 |
| 7.25983 | 3.140328 |
| 7.28725 | 3.140158 |
| 7.31477 | 3.139988 |
| 7.3424 | 3.139816 |
| 7.37013 | 3.139643 |
| 7.39796 | 3.139468 |
| 7.4259 | 3.139292 |
| 7.45395 | 3.139114 |
| 7.4821 | 3.138935 |
| 7.51036 | 3.138755 |
| 7.53872 | 3.138573 |
| 7.56719 | 3.13839 |
| 7.59577 | 3.138205 |
| 7.62446 | 3.138018 |
| 7.65325 | 3.13783 |
| 7.68216 | 3.137641 |
| 7.71117 | 3.13745 |
| 7.7403 | 3.137257 |
| 7.76953 | 3.137062 |
| 7.79887 | 3.136866 |
| 7.82833 | 3.136669 |
| 7.85789 | 3.136469 |
| 7.88757 | 3.136268 |
| 7.91736 | 3.136065 |
| 7.94726 | 3.13586 |
| 7.97727 | 3.135653 |
| 8.0074 | 3.135445 |
| 8.03764 | 3.135235 |
| 8.068 | 3.135023 |
| 8.09847 | 3.134809 |
| 8.12906 | 3.134593 |
| 8.15976 | 3.134375 |
| 8.19058 | 3.134155 |
| 8.22151 | 3.133933 |
| 8.25256 | 3.133709 |
| 8.28373 | 3.133483 |
| 8.31501 | 3.133255 |
| 8.34642 | 3.133025 |
| 8.37794 | 3.132792 |
| 8.40958 | 3.132558 |
| 8.44134 | 3.132321 |
| 8.47322 | 3.132082 |
| 8.50522 | 3.13184 |
| 8.53734 | 3.131597 |
| 8.56959 | 3.131351 |
| 8.60195 | 3.131103 |
| 8.63444 | 3.130852 |
| 8.66705 | 3.130599 |
| 8.69978 | 3.130343 |
| 8.73264 | 3.130085 |
| 8.76562 | 3.129824 |
| 8.79873 | 3.129561 |
| 8.83196 | 3.129295 |
| 8.86531 | 3.129026 |
| 8.89879 | 3.128755 |
| 8.9324 | 3.128481 |
| 8.96614 | 3.128204 |
| 9 | 3.127924 |
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
- —
Extraordinary ray (e); 21-22 °C.