Optical constants

Refractive index of CuGaS₂ (Copper gallium sulfide)

Boyd et al. 1971: n(e) 0.55–11.5 µm; 20 °C

Data: formula 2
Range: 0.55–11.5 µm
Optical axis: e
Licence: CC0-1.0

Uniaxial crystal, axes: oe

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 2.72131
Extinction coefficient k: 0

Permittivity ε₁: 7.40551
Permittivity ε₂: 0

Absorption coefficient α: 0 cm⁻¹
Penetration depth δ = λ/(2πk): — nm

Abbe number V_d: —
Chromatic dispersion dn/dλ: -1.26236 µm⁻¹

Group index n_g: 3.46307
Group velocity dispersion: 4119.17 fs²/mm

Dispersion parameter D: -22472.2 ps/(nm·km)
Photon energy: 2.11001 eV

ε = (n + ik)², α = 4πk/λ, n_g = 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

# CuGaS2 (Copper gallium sulfide): Boyd et al. 1971: n(e) 0.55–11.5 µm; 20 °C
cugas2 = ls.fetch_refractiveindex("main", "CuGaS2", "Boyd-20-e", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(cugas2.range_nm)  # (550, 11500) nm
eps = cugas2.eps([633])  # complex permittivity

Downloads 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_8ee8a488324e/lightsmith"
cugas2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(cugas2.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (cugas2/boyd-1971-20-e).

# ... load cugas2 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=cugas2)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=550, stop_nm=1000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength

Same 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_8ee8a488324e/lightsmith?model=drude_lorentz"
cugas2_dl = ls.DrudeLorentz.model_validate(json.load(urllib.request.urlopen(url)))

A dispersive Drude–Lorentz model for time-domain solvers.

Materials guide Open a sphere of it in Studio Quick start Ask the community

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

n^{2} - 1 = 3.3165 + \frac{1.8692 λ^{2}}{λ^{2} - 0.1364} + \frac{1.7575 λ^{2}}{λ^{2} - 738.43}

Valid from 0.55 to 11.5 µm.

Coefficients as stored

C_i	Value
C1	3.3165
C2	1.8692
C3	0.1364
C4	1.7575
C5	738.43

Comments and conditions

Extrardinary ray (e); 20 °C

References

1) G. D. Boyd, H. Kasper, J. H McFee. Linear and nonlinear optical properties of AgGaS₂, CuGaS₂, and CuInS₂, and theory of the wedge technique for the measurement of nonlinear coefficients. IEEE J. Quantum Electron., 7, 563-573 (1971)
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.1971.1076588 Linear and nonlinear optical properties of AgGaS&lt;inf&gt;2&lt;/inf&gt;, CuGaS&lt;inf&gt;2&lt;/inf&gt;, and CuInS&lt;inf&gt;2&lt;/inf&gt;, and theory of the wedge technique for the measurement of nonlinear coefficients, IEEE Journal of Quantum Electronics (1971)
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, H. Kasper and J. McFee. Linear and nonlinear optical properties of AgGaS&lt;inf&gt;2&lt;/inf&gt;, CuGaS&lt;inf&gt;2&lt;/inf&gt;, and CuInS&lt;inf&gt;2&lt;/inf&gt;, and theory of the wedge technique for the measurement of nonlinear coefficients. IEEE Journal of Quantum Electronics, 7, 563-573 (1971), doi:10.1109/jqe.1971.1076588; 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

CSV comma separated TXT tab separated YAML n, k Full database record original YAML All quantities CSV JSON metadata

CuGaS2 (Copper gallium sulfide), Boyd et al. 1971: n(e) 0.55–11.5 µm; 20 °C: n and k versus wavelength
λ (µm)	n
0.55	2.77848
0.554207	2.770953
0.558446	2.763699
0.562717	2.756704
0.567021	2.749955
0.571358	2.743439
0.575728	2.737147
0.580132	2.731066
0.584569	2.725187
0.58904	2.719502
0.593545	2.714
0.598085	2.708674
0.60266	2.703516
0.607269	2.698519
0.611914	2.693676
0.616594	2.68898
0.62131	2.684426
0.626062	2.680007
0.630851	2.675718
0.635676	2.671554
0.640538	2.66751
0.645437	2.66358
0.650374	2.659762
0.655348	2.65605
0.660361	2.652441
0.665412	2.64893
0.670501	2.645515
0.67563	2.642191
0.680797	2.638955
0.686004	2.635805
0.691251	2.632737
0.696538	2.629748
0.701866	2.626836
0.707234	2.623998
0.712644	2.621232
0.718094	2.618535
0.723587	2.615905
0.729121	2.61334
0.734698	2.610837
0.740317	2.608395
0.74598	2.606011
0.751686	2.603685
0.757435	2.601414
0.763228	2.599196
0.769066	2.59703
0.774948	2.594914
0.780875	2.592847
0.786848	2.590827
0.792866	2.588853
0.798931	2.586924
0.805041	2.585038
0.811199	2.583194
0.817403	2.581391
0.823655	2.579628
0.829955	2.577903
0.836303	2.576216
0.8427	2.574565
0.849145	2.57295
0.85564	2.571369
0.862185	2.569822
0.868779	2.568308
0.875424	2.566825
0.88212	2.565374
0.888867	2.563952
0.895665	2.56256
0.902516	2.561197
0.909419	2.559862
0.916375	2.558553
0.923384	2.557272
0.930446	2.556016
0.937563	2.554785
0.944734	2.553579
0.95196	2.552397
0.959241	2.551238
0.966578	2.550102
0.973971	2.548989
0.98142	2.547897
0.988927	2.546826
0.996491	2.545776
1.00411	2.544746
1.01179	2.543736
1.01953	2.542746
1.02733	2.541774
1.03519	2.54082
1.0431	2.539885
1.05108	2.538967
1.05912	2.538066
1.06722	2.537182
1.07539	2.536314
1.08361	2.535463
1.0919	2.534627
1.10025	2.533806
1.10867	2.533
1.11715	2.532209
1.12569	2.531433
1.1343	2.53067
1.14298	2.529921
1.15172	2.529185
1.16053	2.528463
1.1694	2.527753
1.17835	2.527056
1.18736	2.526371
1.19644	2.525699
1.20559	2.525038
1.21482	2.524388
1.22411	2.52375
1.23347	2.523123
1.2429	2.522507
1.25241	2.521901
1.26199	2.521306
1.27164	2.520721
1.28137	2.520146
1.29117	2.51958
1.30104	2.519024
1.311	2.518478
1.32102	2.51794
1.33113	2.517412
1.34131	2.516892
1.35157	2.516381
1.36191	2.515879
1.37232	2.515384
1.38282	2.514898
1.39339	2.51442
1.40405	2.513949
1.41479	2.513486
1.42561	2.513031
1.43652	2.512583
1.4475	2.512142
1.45858	2.511708
1.46973	2.51128
1.48097	2.51086
1.4923	2.510446
1.50371	2.510039
1.51522	2.509638
1.5268	2.509243
1.53848	2.508855
1.55025	2.508472
1.56211	2.508095
1.57406	2.507724
1.58609	2.507359
1.59823	2.506999
1.61045	2.506645
1.62277	2.506295
1.63518	2.505951
1.64769	2.505613
1.66029	2.505279
1.67299	2.50495
1.68578	2.504625
1.69868	2.504306
1.71167	2.503991
1.72476	2.50368
1.73795	2.503374
1.75125	2.503073
1.76464	2.502775
1.77814	2.502482
1.79174	2.502193
1.80544	2.501907
1.81925	2.501626
1.83317	2.501348
1.84719	2.501075
1.86132	2.500805
1.87555	2.500538
1.8899	2.500275
1.90435	2.500015
1.91892	2.499759
1.9336	2.499506
1.94839	2.499256
1.96329	2.49901
1.97831	2.498766
1.99344	2.498526
2.00868	2.498288
2.02405	2.498054
2.03953	2.497822
2.05513	2.497593
2.07085	2.497367
2.08669	2.497143
2.10265	2.496922
2.11873	2.496703
2.13493	2.496487
2.15126	2.496273
2.16772	2.496062
2.1843	2.495853
2.201	2.495646
2.21784	2.495441
2.2348	2.495239
2.2519	2.495038
2.26912	2.494839
2.28647	2.494643
2.30396	2.494448
2.32159	2.494255
2.33934	2.494064
2.35723	2.493875
2.37526	2.493688
2.39343	2.493502
2.41174	2.493318
2.43018	2.493135
2.44877	2.492954
2.4675	2.492774
2.48637	2.492596
2.50539	2.492419
2.52455	2.492243
2.54386	2.492069
2.56332	2.491896
2.58293	2.491724
2.60268	2.491554
2.62259	2.491384
2.64265	2.491216
2.66286	2.491048
2.68323	2.490882
2.70375	2.490716
2.72443	2.490552
2.74527	2.490388
2.76627	2.490225
2.78743	2.490063
2.80875	2.489901
2.83023	2.48974
2.85188	2.48958
2.87369	2.489421
2.89567	2.489262
2.91782	2.489103
2.94013	2.488945
2.96262	2.488788
2.98528	2.488631
3.00811	2.488474
3.03112	2.488318
3.05431	2.488162
3.07767	2.488006
3.10121	2.48785
3.12493	2.487695
3.14883	2.48754
3.17291	2.487384
3.19718	2.487229
3.22164	2.487074
3.24628	2.486919
3.27111	2.486764
3.29613	2.486608
3.32134	2.486453
3.34674	2.486297
3.37234	2.486142
3.39813	2.485985
3.42412	2.485829
3.45031	2.485672
3.4767	2.485515
3.50329	2.485358
3.53009	2.4852
3.55709	2.485041
3.5843	2.484882
3.61171	2.484723
3.63934	2.484563
3.66717	2.484402
3.69522	2.48424
3.72348	2.484078
3.75196	2.483915
3.78066	2.483751
3.80958	2.483586
3.83872	2.483421
3.86808	2.483254
3.89766	2.483086
3.92747	2.482918
3.95751	2.482748
3.98778	2.482577
4.01828	2.482405
4.04902	2.482232
4.07999	2.482058
4.11119	2.481882
4.14264	2.481705
4.17432	2.481526
4.20625	2.481346
4.23842	2.481165
4.27084	2.480982
4.30351	2.480797
4.33642	2.480611
4.36959	2.480423
4.40301	2.480234
4.43669	2.480042
4.47062	2.479849
4.50482	2.479654
4.53927	2.479457
4.57399	2.479258
4.60898	2.479057
4.64423	2.478854
4.67975	2.478649
4.71555	2.478441
4.75161	2.478231
4.78796	2.478019
4.82458	2.477805
4.86148	2.477588
4.89866	2.477368
4.93613	2.477146
4.97388	2.476922
5.01193	2.476694
5.05026	2.476464
5.08889	2.476231
5.12781	2.475996
5.16703	2.475757
5.20655	2.475515
5.24638	2.47527
5.2865	2.475022
5.32694	2.474771
5.36768	2.474517
5.40874	2.474259
5.45011	2.473998
5.49179	2.473733
5.5338	2.473464
5.57612	2.473192
5.61877	2.472916
5.66175	2.472637
5.70505	2.472353
5.74869	2.472065
5.79266	2.471774
5.83696	2.471478
5.88161	2.471178
5.92659	2.470873
5.97192	2.470564
6.0176	2.470251
6.06363	2.469932
6.11001	2.469609
6.15674	2.469282
6.20383	2.468949
6.25128	2.468611
6.29909	2.468268
6.34727	2.46792
6.39582	2.467566
6.44474	2.467207
6.49403	2.466843
6.5437	2.466472
6.59375	2.466096
6.64419	2.465714
6.69501	2.465326
6.74621	2.464931
6.79781	2.46453
6.84981	2.464123
6.9022	2.463709
6.95499	2.463288
7.00819	2.46286
7.06179	2.462426
7.1158	2.461984
7.17023	2.461534
7.22507	2.461078
7.28033	2.460613
7.33602	2.460141
7.39213	2.459661
7.44867	2.459172
7.50564	2.458675
7.56305	2.45817
7.62089	2.457656
7.67918	2.457133
7.73792	2.456601
7.7971	2.456059
7.85674	2.455508
7.91683	2.454948
7.97738	2.454377
8.0384	2.453797
8.09988	2.453205
8.16184	2.452604
8.22426	2.451991
8.28717	2.451368
8.35055	2.450733
8.41442	2.450086
8.47878	2.449428
8.54363	2.448758
8.60898	2.448075
8.67483	2.447379
8.74118	2.446671
8.80803	2.445949
8.8754	2.445214
8.94329	2.444465
9.01169	2.443701
9.08062	2.442923
9.15007	2.44213
9.22006	2.441322
9.29058	2.440499
9.36164	2.439659
9.43324	2.438803
9.50539	2.43793
9.5781	2.43704
9.65136	2.436132
9.72517	2.435206
9.79956	2.434262
9.87451	2.433299
9.95004	2.432316
10.0261	2.431314
10.1028	2.430291
10.1801	2.429247
10.258	2.428181
10.3364	2.427094
10.4155	2.425984
10.4951	2.42485
10.5754	2.423693
10.6563	2.422511
10.7378	2.421304
10.8199	2.420072
10.9027	2.418812
10.9861	2.417526
11.0701	2.416211
11.1548	2.414868
11.2401	2.413495
11.3261	2.412092
11.4127	2.410657
11.5	2.40919

Optical transmission calculator

Free-standing sample in vacuum, normal incidence

Transmittance T: —
Reflectance R: —

Fresnel reflection calculator

R_p: —
R_s: —
R = (R_p+R_s)/2: —
Phase φ_p: —
Phase φ_s: —
Brewster angle θ_B: —
Critical angle θ_C: —

CuGaS₂ (Copper gallium sulfide): all datasets

About CuGaS2 (Copper gallium sulfide)

Copper gallium sulfide (CuGaS₂) is a ternary compound semiconductor that exhibits a chalcopyrite crystal structure. This material is notable for its non-linear optical properties and is frequently employed in non-linear frequency conversion applications such as second-harmonic generation and parametric down-conversion. Its large non-linear coefficients and extensive phase-matching capabilities make it an ideal choice for infrared and mid-infrared applications. The material also boasts high thermal conductivity and damage threshold, which lends itself well to high-power optical systems. While not as commonly used as some other non-linear optical materials, copper gallium sulfide remains a specialized choice for applications requiring efficient non-linear frequency conversion, particularly in the infrared spectrum.

More about CuGaS2 (Copper gallium sulfide) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/CuGaS2/nk/Boyd-20-e.yml
ID: ds_8ee8a488324e
API: /v1/datasets/ds_8ee8a488324e

Plot