Optical constants

Refractive index of CdGeP2 (Cadmium germanium phosphide)

Boyd et al. 1972: n(o) 0.8–12.5 µm; 20 °C

Data
formula 2
Range
0.8–12.5 µm
Temperature
293 K
Optical axis
o
Licence
CC0-1.0

Uniaxial crystal, axes: oe

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.8–12.5 µm
Refractive index n
3.20296
Extinction coefficient k
0
Permittivity ε1
10.259
Permittivity ε2
0
Absorption coefficient α
0 cm⁻¹
Penetration depth δ = λ/(2πk)
— nm
Abbe number Vd
—
Chromatic dispersion dn/dλ
-0.0112847 µm⁻¹
Group index ng
3.23862
Group velocity dispersion
431.508 fs²/mm
Dispersion parameter D
-81.3983 ps/(nm·km)
Photon energy
0.392355 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

# CdGeP2 (Cadmium germanium phosphide): Boyd et al. 1972: n(o) 0.8–12.5 µm; 20 °C
cdgep2 = ls.fetch_refractiveindex("main", "CdGeP2", "Boyd-20-o", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(cdgep2.range_nm)  # (800, 12500) nm
eps = cdgep2.eps([3160])  # complex permittivity

Downloads the original record once (pinned to the imported snapshot) and caches it.

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 µm
n2−1=4.9677+4.2286λ2λ2−0.2021+1.6351λ2λ2−671.33

Valid from 0.8 to 12.5 µm.

Coefficients as stored
CiValue
C14.9677
C24.2286
C30.2021
C41.6351
C5671.33

Comments and conditions

Ordinary ray (o); 20 °C

Conditions

temperature
293 K
direction
o

References

1) G. D. Boyd, E. Buehler, F. G Storz, J. H. Wernick. Linear and nonlinear optical properties of ternary AIIBIVC2V chalcopyrite semiconductors. IEEE J. Quantum Electron., 8, 419-426 (1972)
2) G. C. Bhar and G. Ghosh. Temperature-dependent Sellmeier coefficients and coherence lengths for some chalcopyrite crystals. J. Opt. Soc. Am. 69, 730-733 (1979)
* Ref. 2 provides a dispersion formula based on data from Ref. 1
  • doi:10.1109/jqe.1972.1076982 Linear and nonlinear optical properties of ternary A<sup>II</sup>B<sup>IV</sup>C<inf>2</inf><sup>V</sup>chalcopyrite semiconductors, IEEE Journal of Quantum Electronics (1972)
  • doi:10.1364/josa.69.000730 Temperature-dependent Sellmeier coefficients and coherence lengths for some chalcopyrite crystals, Journal of the Optical Society of America (1979)

Cite

G. Boyd, E. Buehler, F. Storz and J. Wernick. Linear and nonlinear optical properties of ternary A<sup>II</sup>B<sup>IV</sup>C<inf>2</inf><sup>V</sup>chalcopyrite semiconductors. IEEE Journal of Quantum Electronics, 8, 419-426 (1972), doi:10.1109/jqe.1972.1076982; Gopal C. Bhar and Gorachand Ghosh. Temperature-dependent Sellmeier coefficients and coherence lengths for some chalcopyrite crystals. Journal of the Optical Society of America, 69, 730 (1979), doi:10.1364/josa.69.000730; 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
CdGeP2 (Cadmium germanium phosphide), Boyd et al. 1972: n(o) 0.8–12.5 µm; 20 °C: n and k versus wavelength
λ (µm)n
0.83.485158
0.8055313.479586
0.8110993.47415
0.8167073.468844
0.8223533.463666
0.8280383.458611
0.8337623.453674
0.8395263.448853
0.845333.444144
0.8511743.439543
0.8570583.435047
0.8629833.430653
0.8689493.426357
0.8749563.422158
0.8810053.418052
0.8870963.414036
0.8932283.410107
0.8994033.406265
0.9056213.402505
0.9118823.398825
0.9181863.395224
0.9245333.391699
0.9309253.388248
0.9373613.384869
0.9438413.381561
0.9503663.37832
0.9569363.375146
0.9635513.372037
0.9702123.368991
0.976923.366006
0.9836733.363081
0.9904743.360215
0.9973213.357405
1.004223.35465
1.011163.35195
1.018153.349302
1.025193.346706
1.032273.34416
1.039413.341663
1.04663.339213
1.053833.33681
1.061123.334453
1.068453.33214
1.075843.32987
1.083283.327643
1.090773.325457
1.098313.323312
1.10593.321206
1.113543.319139
1.121243.317109
1.128993.315117
1.13683.31316
1.144663.311239
1.152573.309352
1.160543.307499
1.168563.305679
1.176643.303892
1.184773.302135
1.192973.30041
1.201213.298715
1.209523.29705
1.217883.295413
1.22633.293805
1.234783.292225
1.243313.290672
1.251913.289145
1.260563.287645
1.269283.28617
1.278053.28472
1.286893.283295
1.295783.281893
1.304743.280516
1.313763.279161
1.322843.277829
1.331993.276519
1.34123.27523
1.350473.273963
1.35983.272717
1.36923.271491
1.378673.270286
1.38823.2691
1.39783.267933
1.407463.266785
1.417193.265656
1.426993.264545
1.436853.263451
1.446793.262376
1.456793.261317
1.466863.260275
1.4773.25925
1.487213.258241
1.497493.257248
1.507853.25627
1.518273.255308
1.528773.254361
1.539333.253428
1.549983.252511
1.560693.251607
1.571483.250717
1.582343.249841
1.593283.248979
1.60433.248129
1.615393.247293
1.626563.246469
1.63783.245658
1.649123.244859
1.660523.244073
1.6723.243298
1.683563.242534
1.69523.241782
1.706923.241042
1.718723.240312
1.73063.239593
1.742573.238885
1.754613.238187
1.766743.2375
1.778963.236822
1.791263.236155
1.803643.235497
1.816113.234849
1.828663.23421
1.84133.23358
1.854033.23296
1.866853.232348
1.879763.231745
1.892753.231151
1.905843.230565
1.919013.229988
1.932283.229418
1.945643.228857
1.959093.228303
1.972633.227757
1.986273.227219
23.226688
2.013833.226165
2.027753.225649
2.041773.22514
2.055883.224638
2.070093.224142
2.084413.223654
2.098823.223172
2.113323.222696
2.127933.222227
2.142653.221764
2.157463.221307
2.172373.220856
2.187393.220412
2.202513.219973
2.217743.21954
2.233073.219112
2.248513.21869
2.264053.218273
2.27973.217862
2.295463.217456
2.311333.217055
2.327313.216659
2.34343.216268
2.35963.215882
2.375913.215501
2.392343.215125
2.408883.214753
2.425533.214385
2.44233.214022
2.459183.213664
2.476183.21331
2.49333.212959
2.510543.212613
2.527893.212272
2.545373.211934
2.562973.2116
2.580693.211269
2.598533.210943
2.616493.21062
2.634583.210301
2.652793.209986
2.671133.209673
2.68963.209365
2.708193.209059
2.726913.208757
2.745773.208458
2.764753.208163
2.783863.20787
2.803113.20758
2.822483.207293
2.8423.20701
2.861643.206729
2.881433.20645
2.901353.206175
2.92143.205902
2.94163.205632
2.961943.205364
2.982413.205099
3.003033.204836
3.023793.204575
3.04473.204317
3.065743.204061
3.086943.203807
3.108283.203556
3.129773.203306
3.15143.203059
3.173193.202813
3.195133.20257
3.217213.202328
3.239463.202088
3.261853.20185
3.28443.201614
3.307113.201379
3.329973.201146
3.352993.200915
3.376173.200685
3.399513.200457
3.423013.20023
3.446683.200004
3.47053.19978
3.49453.199557
3.518653.199336
3.542983.199115
3.567473.198896
3.592133.198678
3.616973.198461
3.641973.198245
3.667153.19803
3.69253.197816
3.718033.197602
3.743733.19739
3.769613.197178
3.795673.196968
3.821913.196758
3.848333.196548
3.874943.196339
3.901733.196131
3.92873.195923
3.955863.195716
3.983213.195509
4.010743.195303
4.038473.195097
4.066393.194891
4.09453.194686
4.122813.194481
4.151313.194276
4.180013.194071
4.208913.193866
4.2383.193662
4.26733.193457
4.29683.193253
4.326513.193048
4.356423.192843
4.386533.192638
4.416863.192433
4.447393.192227
4.478143.192022
4.50913.191816
4.540273.191609
4.571663.191402
4.603263.191195
4.635083.190987
4.667133.190779
4.699393.19057
4.731883.19036
4.764593.19015
4.797533.189939
4.83073.189727
4.864093.189514
4.897723.189301
4.931583.189086
4.965673.188871
53.188654
5.034573.188437
5.069373.188218
5.104423.187998
5.13973.187777
5.175243.187555
5.211013.187331
5.247043.187106
5.283313.18688
5.319843.186652
5.356613.186423
5.393643.186192
5.430933.185959
5.468483.185725
5.506283.185489
5.544353.185251
5.582683.185011
5.621273.184769
5.660133.184526
5.699263.18428
5.738663.184032
5.778333.183783
5.818283.183531
5.85853.183276
5.8993.18302
5.939793.182761
5.980853.182499
6.02223.182235
6.063833.181968
6.105753.181699
6.147963.181427
6.190463.181153
6.233263.180875
6.276353.180594
6.319743.180311
6.363433.180024
6.407423.179734
6.451713.179442
6.496323.179145
6.541233.178846
6.586453.178543
6.631983.178236
6.677833.177926
6.723993.177612
6.770483.177294
6.817283.176972
6.864413.176647
6.911873.176317
6.959653.175983
7.007763.175645
7.056213.175303
7.104993.174956
7.154113.174605
7.203573.174249
7.253373.173889
7.303513.173523
7.3543.173153
7.404843.172777
7.456033.172397
7.507583.172011
7.559483.17162
7.611743.171223
7.664363.170821
7.717343.170413
7.77073.169999
7.824423.169579
7.878513.169153
7.932973.168721
7.987823.168282
8.043043.167837
8.098643.167385
8.154633.166926
8.2113.16646
8.267773.165987
8.324923.165507
8.382473.16502
8.440423.164525
8.498773.164022
8.557533.163511
8.616693.162992
8.676263.162464
8.736243.161929
8.796633.161384
8.857453.160831
8.918683.160268
8.980343.159697
9.042423.159115
9.104933.158524
9.167873.157924
9.231253.157313
9.295073.156691
9.359333.156059
9.424033.155416
9.489183.154762
9.554783.154097
9.620843.15342
9.687353.152731
9.754323.15203
9.821753.151316
9.889653.15059
9.958023.14985
10.02693.149097
10.09623.148331
10.1663.14755
10.23633.146755
10.3073.145945
10.37833.14512
10.453.14428
10.52233.143423
10.5953.14255
10.66833.141661
10.7423.140754
10.81633.13983
10.8913.138888
10.96633.137927
11.04213.136948
11.11853.135949
11.19533.13493
11.27273.13389
11.35073.132829
11.42913.131747
11.50823.130642
11.58773.129515
11.66783.128364
11.74853.127189
11.82973.125989
11.91153.124764
11.99383.123513
12.07673.122234
12.16023.120928
12.24433.119593
12.32893.118228
12.41423.116834
12.53.115408

Optical transmission calculator

Free-standing sample in vacuum, normal incidence
Method
Transmittance T
—
Reflectance R
—

Fresnel reflection calculator

Direction
Rp
—
Rs
—
R = (Rp+Rs)/2
—
Phase φp
—
Phase φs
—
Brewster angle θB
—
Critical angle θC
—