Optical constants
Refractive index of ZnGeP2 (Zinc germanium phosphide, ZGP)
Ghosh 1998: n(e) 0.7–12 µm; 250 K
- Data
- formula 2
- Range
- 0.7–12 µm
- Temperature
- 250 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
- 3.16192
- Extinction coefficient k
- 0
- Permittivity ε1
- 9.99777
- Permittivity ε2
- 0
- Absorption coefficient α
- 0 cm⁻¹
- Penetration depth δ = λ/(2πk)
- — nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.0121401 µm⁻¹
- Group index ng
- 3.19713
- Group velocity dispersion
- 419.161 fs²/mm
- Dispersion parameter D
- -93.8828 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; 250 K
zngep2 = ls.fetch_refractiveindex("main", "ZnGeP2", "Ghosh-250K-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_f90bee6c2029/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-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_f90bee6c2029/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 | 3.62177621 |
| C2 | 5.30603357 |
| C3 | 0.13993953 |
| C4 | 2.10214323 |
| C5 | 900.0 |
Comments and conditions
Conditions
- temperature
- 250 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 | 3.470993 |
| 0.705003 | 3.464971 |
| 0.710042 | 3.45909 |
| 0.715117 | 3.453345 |
| 0.720228 | 3.447732 |
| 0.725375 | 3.442248 |
| 0.73056 | 3.436889 |
| 0.735781 | 3.43165 |
| 0.74104 | 3.426529 |
| 0.746336 | 3.421521 |
| 0.75167 | 3.416624 |
| 0.757043 | 3.411835 |
| 0.762453 | 3.40715 |
| 0.767903 | 3.402566 |
| 0.773391 | 3.398081 |
| 0.778919 | 3.393692 |
| 0.784486 | 3.389396 |
| 0.790093 | 3.385191 |
| 0.79574 | 3.381074 |
| 0.801427 | 3.377043 |
| 0.807155 | 3.373096 |
| 0.812924 | 3.36923 |
| 0.818734 | 3.365444 |
| 0.824585 | 3.361735 |
| 0.830479 | 3.358101 |
| 0.836414 | 3.35454 |
| 0.842392 | 3.351051 |
| 0.848413 | 3.347632 |
| 0.854477 | 3.34428 |
| 0.860584 | 3.340995 |
| 0.866735 | 3.337774 |
| 0.87293 | 3.334617 |
| 0.879169 | 3.331521 |
| 0.885452 | 3.328485 |
| 0.891781 | 3.325507 |
| 0.898154 | 3.322587 |
| 0.904574 | 3.319723 |
| 0.911039 | 3.316913 |
| 0.91755 | 3.314156 |
| 0.924108 | 3.311451 |
| 0.930713 | 3.308798 |
| 0.937365 | 3.306193 |
| 0.944064 | 3.303638 |
| 0.950812 | 3.301129 |
| 0.957607 | 3.298667 |
| 0.964451 | 3.296251 |
| 0.971345 | 3.293878 |
| 0.978287 | 3.291549 |
| 0.985279 | 3.289263 |
| 0.992321 | 3.287017 |
| 0.999413 | 3.284812 |
| 1.00656 | 3.282647 |
| 1.01375 | 3.280521 |
| 1.021 | 3.278433 |
| 1.02829 | 3.276381 |
| 1.03564 | 3.274366 |
| 1.04304 | 3.272387 |
| 1.0505 | 3.270443 |
| 1.05801 | 3.268532 |
| 1.06557 | 3.266655 |
| 1.07318 | 3.264811 |
| 1.08085 | 3.262999 |
| 1.08858 | 3.261218 |
| 1.09636 | 3.259468 |
| 1.1042 | 3.257748 |
| 1.11209 | 3.256057 |
| 1.12004 | 3.254395 |
| 1.12804 | 3.252762 |
| 1.1361 | 3.251157 |
| 1.14422 | 3.249578 |
| 1.1524 | 3.248026 |
| 1.16064 | 3.246501 |
| 1.16893 | 3.245001 |
| 1.17729 | 3.243526 |
| 1.1857 | 3.242076 |
| 1.19418 | 3.24065 |
| 1.20271 | 3.239247 |
| 1.21131 | 3.237868 |
| 1.21997 | 3.236512 |
| 1.22868 | 3.235178 |
| 1.23747 | 3.233865 |
| 1.24631 | 3.232575 |
| 1.25522 | 3.231305 |
| 1.26419 | 3.230056 |
| 1.27322 | 3.228828 |
| 1.28232 | 3.227619 |
| 1.29149 | 3.22643 |
| 1.30072 | 3.22526 |
| 1.31002 | 3.224109 |
| 1.31938 | 3.222976 |
| 1.32881 | 3.221862 |
| 1.33831 | 3.220765 |
| 1.34787 | 3.219686 |
| 1.35751 | 3.218623 |
| 1.36721 | 3.217578 |
| 1.37698 | 3.216549 |
| 1.38682 | 3.215537 |
| 1.39673 | 3.21454 |
| 1.40672 | 3.213559 |
| 1.41677 | 3.212594 |
| 1.4269 | 3.211643 |
| 1.43709 | 3.210707 |
| 1.44736 | 3.209786 |
| 1.45771 | 3.208879 |
| 1.46813 | 3.207987 |
| 1.47862 | 3.207107 |
| 1.48919 | 3.206242 |
| 1.49983 | 3.20539 |
| 1.51055 | 3.204551 |
| 1.52135 | 3.203724 |
| 1.53222 | 3.202911 |
| 1.54317 | 3.202109 |
| 1.5542 | 3.20132 |
| 1.56531 | 3.200543 |
| 1.5765 | 3.199777 |
| 1.58776 | 3.199023 |
| 1.59911 | 3.198281 |
| 1.61054 | 3.197549 |
| 1.62205 | 3.196829 |
| 1.63365 | 3.196119 |
| 1.64532 | 3.19542 |
| 1.65708 | 3.194731 |
| 1.66892 | 3.194053 |
| 1.68085 | 3.193384 |
| 1.69287 | 3.192725 |
| 1.70497 | 3.192076 |
| 1.71715 | 3.191437 |
| 1.72942 | 3.190807 |
| 1.74178 | 3.190186 |
| 1.75423 | 3.189574 |
| 1.76677 | 3.188971 |
| 1.7794 | 3.188376 |
| 1.79212 | 3.187791 |
| 1.80492 | 3.187213 |
| 1.81782 | 3.186644 |
| 1.83082 | 3.186083 |
| 1.8439 | 3.18553 |
| 1.85708 | 3.184985 |
| 1.87035 | 3.184448 |
| 1.88372 | 3.183918 |
| 1.89719 | 3.183396 |
| 1.91074 | 3.182881 |
| 1.9244 | 3.182373 |
| 1.93816 | 3.181873 |
| 1.95201 | 3.181379 |
| 1.96596 | 3.180892 |
| 1.98001 | 3.180412 |
| 1.99416 | 3.179939 |
| 2.00841 | 3.179472 |
| 2.02277 | 3.179011 |
| 2.03723 | 3.178557 |
| 2.05179 | 3.178109 |
| 2.06645 | 3.177666 |
| 2.08122 | 3.17723 |
| 2.09609 | 3.1768 |
| 2.11108 | 3.176375 |
| 2.12616 | 3.175956 |
| 2.14136 | 3.175543 |
| 2.15666 | 3.175135 |
| 2.17208 | 3.174732 |
| 2.1876 | 3.174335 |
| 2.20324 | 3.173943 |
| 2.21899 | 3.173556 |
| 2.23484 | 3.173174 |
| 2.25082 | 3.172797 |
| 2.2669 | 3.172424 |
| 2.28311 | 3.172056 |
| 2.29942 | 3.171693 |
| 2.31586 | 3.171335 |
| 2.33241 | 3.170981 |
| 2.34908 | 3.170631 |
| 2.36587 | 3.170286 |
| 2.38278 | 3.169945 |
| 2.39981 | 3.169608 |
| 2.41696 | 3.169275 |
| 2.43424 | 3.168946 |
| 2.45163 | 3.168621 |
| 2.46916 | 3.1683 |
| 2.4868 | 3.167983 |
| 2.50458 | 3.167669 |
| 2.52248 | 3.167359 |
| 2.54051 | 3.167052 |
| 2.55866 | 3.166749 |
| 2.57695 | 3.16645 |
| 2.59537 | 3.166154 |
| 2.61392 | 3.165861 |
| 2.6326 | 3.165571 |
| 2.65142 | 3.165285 |
| 2.67037 | 3.165001 |
| 2.68945 | 3.164721 |
| 2.70867 | 3.164444 |
| 2.72803 | 3.164169 |
| 2.74753 | 3.163898 |
| 2.76717 | 3.163629 |
| 2.78695 | 3.163363 |
| 2.80686 | 3.163099 |
| 2.82693 | 3.162838 |
| 2.84713 | 3.16258 |
| 2.86748 | 3.162324 |
| 2.88797 | 3.162071 |
| 2.90861 | 3.16182 |
| 2.9294 | 3.161572 |
| 2.95034 | 3.161325 |
| 2.97143 | 3.161081 |
| 2.99266 | 3.160839 |
| 3.01405 | 3.160599 |
| 3.03559 | 3.160362 |
| 3.05729 | 3.160126 |
| 3.07914 | 3.159892 |
| 3.10115 | 3.15966 |
| 3.12331 | 3.15943 |
| 3.14564 | 3.159202 |
| 3.16812 | 3.158976 |
| 3.19076 | 3.158751 |
| 3.21357 | 3.158528 |
| 3.23653 | 3.158306 |
| 3.25967 | 3.158086 |
| 3.28296 | 3.157868 |
| 3.30643 | 3.157651 |
| 3.33006 | 3.157436 |
| 3.35386 | 3.157221 |
| 3.37783 | 3.157009 |
| 3.40197 | 3.156797 |
| 3.42629 | 3.156587 |
| 3.45078 | 3.156378 |
| 3.47544 | 3.15617 |
| 3.50028 | 3.155963 |
| 3.5253 | 3.155757 |
| 3.55049 | 3.155552 |
| 3.57587 | 3.155349 |
| 3.60142 | 3.155146 |
| 3.62716 | 3.154944 |
| 3.65309 | 3.154743 |
| 3.6792 | 3.154542 |
| 3.70549 | 3.154342 |
| 3.73198 | 3.154144 |
| 3.75865 | 3.153945 |
| 3.78551 | 3.153748 |
| 3.81257 | 3.15355 |
| 3.83982 | 3.153354 |
| 3.86726 | 3.153158 |
| 3.8949 | 3.152962 |
| 3.92274 | 3.152767 |
| 3.95078 | 3.152572 |
| 3.97901 | 3.152378 |
| 4.00745 | 3.152183 |
| 4.03609 | 3.151989 |
| 4.06494 | 3.151795 |
| 4.09399 | 3.151602 |
| 4.12325 | 3.151408 |
| 4.15272 | 3.151214 |
| 4.1824 | 3.151021 |
| 4.2123 | 3.150827 |
| 4.2424 | 3.150634 |
| 4.27272 | 3.15044 |
| 4.30326 | 3.150246 |
| 4.33402 | 3.150052 |
| 4.36499 | 3.149858 |
| 4.39619 | 3.149663 |
| 4.42761 | 3.149468 |
| 4.45926 | 3.149273 |
| 4.49113 | 3.149077 |
| 4.52323 | 3.148881 |
| 4.55556 | 3.148685 |
| 4.58812 | 3.148487 |
| 4.62091 | 3.14829 |
| 4.65393 | 3.148091 |
| 4.6872 | 3.147892 |
| 4.7207 | 3.147692 |
| 4.75444 | 3.147492 |
| 4.78842 | 3.14729 |
| 4.82264 | 3.147088 |
| 4.85711 | 3.146885 |
| 4.89182 | 3.146681 |
| 4.92679 | 3.146476 |
| 4.962 | 3.14627 |
| 4.99746 | 3.146063 |
| 5.03318 | 3.145854 |
| 5.06915 | 3.145645 |
| 5.10538 | 3.145434 |
| 5.14187 | 3.145222 |
| 5.17862 | 3.145009 |
| 5.21564 | 3.144794 |
| 5.25291 | 3.144578 |
| 5.29046 | 3.14436 |
| 5.32827 | 3.144141 |
| 5.36635 | 3.14392 |
| 5.4047 | 3.143698 |
| 5.44333 | 3.143474 |
| 5.48224 | 3.143248 |
| 5.52142 | 3.14302 |
| 5.56088 | 3.142791 |
| 5.60063 | 3.142559 |
| 5.64066 | 3.142326 |
| 5.68097 | 3.14209 |
| 5.72157 | 3.141853 |
| 5.76247 | 3.141613 |
| 5.80365 | 3.141372 |
| 5.84513 | 3.141128 |
| 5.88691 | 3.140881 |
| 5.92898 | 3.140633 |
| 5.97136 | 3.140381 |
| 6.01404 | 3.140128 |
| 6.05702 | 3.139872 |
| 6.10031 | 3.139613 |
| 6.14391 | 3.139351 |
| 6.18782 | 3.139087 |
| 6.23205 | 3.13882 |
| 6.27659 | 3.13855 |
| 6.32145 | 3.138277 |
| 6.36663 | 3.138001 |
| 6.41213 | 3.137722 |
| 6.45796 | 3.13744 |
| 6.50412 | 3.137154 |
| 6.5506 | 3.136866 |
| 6.59742 | 3.136573 |
| 6.64457 | 3.136278 |
| 6.69206 | 3.135979 |
| 6.73989 | 3.135676 |
| 6.78807 | 3.135369 |
| 6.83658 | 3.135059 |
| 6.88544 | 3.134745 |
| 6.93465 | 3.134427 |
| 6.98422 | 3.134105 |
| 7.03414 | 3.133778 |
| 7.08441 | 3.133448 |
| 7.13504 | 3.133113 |
| 7.18604 | 3.132774 |
| 7.2374 | 3.13243 |
| 7.28913 | 3.132082 |
| 7.34122 | 3.131729 |
| 7.39369 | 3.131371 |
| 7.44654 | 3.131008 |
| 7.49976 | 3.130641 |
| 7.55336 | 3.130268 |
| 7.60734 | 3.12989 |
| 7.66172 | 3.129507 |
| 7.71647 | 3.129118 |
| 7.77163 | 3.128724 |
| 7.82717 | 3.128324 |
| 7.88311 | 3.127918 |
| 7.93946 | 3.127506 |
| 7.9962 | 3.127089 |
| 8.05335 | 3.126665 |
| 8.11091 | 3.126235 |
| 8.16888 | 3.125798 |
| 8.22726 | 3.125355 |
| 8.28607 | 3.124906 |
| 8.34529 | 3.124449 |
| 8.40493 | 3.123986 |
| 8.465 | 3.123515 |
| 8.5255 | 3.123037 |
| 8.58644 | 3.122552 |
| 8.64781 | 3.122059 |
| 8.70961 | 3.121558 |
| 8.77186 | 3.12105 |
| 8.83456 | 3.120533 |
| 8.8977 | 3.120009 |
| 8.96129 | 3.119475 |
| 9.02534 | 3.118934 |
| 9.08985 | 3.118383 |
| 9.15481 | 3.117824 |
| 9.22024 | 3.117255 |
| 9.28614 | 3.116677 |
| 9.35251 | 3.11609 |
| 9.41936 | 3.115492 |
| 9.48668 | 3.114885 |
| 9.55448 | 3.114268 |
| 9.62277 | 3.11364 |
| 9.69155 | 3.113002 |
| 9.76081 | 3.112352 |
| 9.83057 | 3.111692 |
| 9.90084 | 3.11102 |
| 9.9716 | 3.110337 |
| 10.0429 | 3.109642 |
| 10.1146 | 3.108934 |
| 10.1869 | 3.108215 |
| 10.2597 | 3.107482 |
| 10.3331 | 3.106737 |
| 10.4069 | 3.105978 |
| 10.4813 | 3.105206 |
| 10.5562 | 3.10442 |
| 10.6317 | 3.10362 |
| 10.7077 | 3.102805 |
| 10.7842 | 3.101975 |
| 10.8613 | 3.101131 |
| 10.9389 | 3.10027 |
| 11.0171 | 3.099394 |
| 11.0958 | 3.098501 |
| 11.1751 | 3.097592 |
| 11.255 | 3.096665 |
| 11.3354 | 3.095721 |
| 11.4164 | 3.094759 |
| 11.498 | 3.093779 |
| 11.5802 | 3.09278 |
| 11.663 | 3.091762 |
| 11.7463 | 3.090723 |
| 11.8303 | 3.089665 |
| 11.9148 | 3.088586 |
| 12 | 3.087485 |
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.