Optical constants

Refractive index of CsF (Cesium fluoride)

Li 1976: n 0.15–30 µm

Data: formula 1
Range: 0.15–30 µm
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.47799
Extinction coefficient k: 0

Permittivity ε₁: 2.18447
Permittivity ε₂: 0

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

Abbe number V_d: 80.972
Chromatic dispersion dn/dλ: -0.0301975 µm⁻¹

Group index n_g: 1.49574
Group velocity dispersion: 57.4694 fs²/mm

Dispersion parameter D: -313.526 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

# CsF (Cesium fluoride): Li 1976: n 0.15–30 µm
csf = ls.fetch_refractiveindex("main", "CsF", "Li", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(csf.range_nm)  # (150, 30000) nm
eps = csf.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_6e31f8be5019/lightsmith"
csf = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(csf.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (csf/li-1976).

# ... load csf as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=csf)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, 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_6e31f8be5019/lightsmith?model=drude_lorentz"
csf_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 (formula 1), λ in µm

n^{2} - 1 = 0.6 + \frac{0.56 λ^{2}}{λ^{2} - {0.121}^{2}} + \frac{5.92 λ^{2}}{λ^{2} - {78.74}^{2}}

Valid from 0.15 to 30.0 µm.

Coefficients as stored

C_i	Value
C1	0.6
C2	0.56
C3	0.121
C4	5.92
C5	78.74

Comments and conditions

α-CsF. 297 K (24 °C).

References

H. H. Li. Refractive index of alkali halides and its wavelength and temperature derivatives. J. Phys. Chem. Ref. Data 5, 329-528 (1976) and references therein.
* Sellmeier formula derivation is based on a single data point and knowledge of the dielectric constants and the characteristic absorption peaks.

doi:10.1063/1.555536 Refractive index of alkali halides and its wavelength and temperature derivatives, Journal of Physical and Chemical Reference Data (1976)

Cite

H. H. Li. Refractive index of alkali halides and its wavelength and temperature derivatives. Journal of Physical and Chemical Reference Data, 5, 329-528 (1976), doi:10.1063/1.555536; 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

CsF (Cesium fluoride), Li 1976: n 0.15–30 µm: n and k versus wavelength
λ (µm)	n
0.15	1.789759
0.152005	1.768785
0.154037	1.749945
0.156096	1.732933
0.158183	1.717497
0.160297	1.703432
0.16244	1.690565
0.164612	1.678753
0.166812	1.667874
0.169042	1.657824
0.171302	1.648515
0.173591	1.639871
0.175912	1.631824
0.178263	1.624318
0.180646	1.617302
0.183061	1.610732
0.185508	1.604567
0.187988	1.598775
0.190501	1.593323
0.193047	1.588184
0.195628	1.583334
0.198243	1.57875
0.200893	1.574413
0.203579	1.570304
0.2063	1.566408
0.209058	1.562708
0.211852	1.559193
0.214684	1.55585
0.217554	1.552667
0.220462	1.549634
0.223409	1.546742
0.226396	1.543982
0.229422	1.541347
0.232489	1.538828
0.235597	1.536419
0.238746	1.534114
0.241937	1.531907
0.245171	1.529793
0.248449	1.527766
0.25177	1.525822
0.255136	1.523957
0.258546	1.522166
0.262002	1.520446
0.265505	1.518793
0.269054	1.517204
0.27265	1.515675
0.276295	1.514205
0.279988	1.512789
0.283731	1.511426
0.287524	1.510113
0.291367	1.508848
0.295262	1.507629
0.299209	1.506453
0.303209	1.505319
0.307262	1.504225
0.311369	1.503169
0.315532	1.50215
0.319749	1.501166
0.324024	1.500215
0.328355	1.499297
0.332744	1.498409
0.337192	1.497552
0.3417	1.496722
0.346268	1.49592
0.350896	1.495145
0.355587	1.494394
0.36034	1.493668
0.365157	1.492966
0.370038	1.492285
0.374985	1.491627
0.379997	1.490989
0.385077	1.490372
0.390225	1.489774
0.395441	1.489194
0.400727	1.488632
0.406084	1.488088
0.411512	1.487561
0.417013	1.487049
0.422588	1.486554
0.428236	1.486073
0.433961	1.485607
0.439762	1.485154
0.44564	1.484716
0.451598	1.48429
0.457634	1.483877
0.463752	1.483477
0.469951	1.483088
0.476233	1.48271
0.482599	1.482344
0.48905	1.481988
0.495588	1.481642
0.502213	1.481307
0.508926	1.480981
0.515729	1.480665
0.522623	1.480357
0.529609	1.480059
0.536689	1.479768
0.543863	1.479486
0.551133	1.479212
0.5585	1.478946
0.565966	1.478687
0.573532	1.478436
0.581199	1.478191
0.588968	1.477953
0.596841	1.477722
0.604819	1.477497
0.612904	1.477279
0.621097	1.477066
0.6294	1.476859
0.637813	1.476658
0.646339	1.476462
0.654979	1.476272
0.663735	1.476086
0.672607	1.475906
0.681598	1.47573
0.690709	1.475559
0.699943	1.475392
0.709299	1.47523
0.718781	1.475073
0.728389	1.474919
0.738126	1.474769
0.747993	1.474623
0.757992	1.474481
0.768124	1.474343
0.778392	1.474208
0.788797	1.474076
0.799341	1.473948
0.810027	1.473823
0.820855	1.473701
0.831828	1.473582
0.842947	1.473466
0.854215	1.473353
0.865634	1.473243
0.877205	1.473135
0.888931	1.47303
0.900814	1.472927
0.912856	1.472827
0.925059	1.472729
0.937424	1.472633
0.949955	1.47254
0.962654	1.472448
0.975522	1.472359
0.988563	1.472272
1.00178	1.472186
1.01517	1.472103
1.02874	1.472021
1.04249	1.471941
1.05643	1.471862
1.07055	1.471785
1.08486	1.47171
1.09936	1.471636
1.11406	1.471564
1.12895	1.471493
1.14404	1.471423
1.15933	1.471354
1.17483	1.471287
1.19053	1.471221
1.20645	1.471156
1.22258	1.471092
1.23892	1.471029
1.25548	1.470967
1.27226	1.470906
1.28927	1.470846
1.3065	1.470787
1.32397	1.470729
1.34167	1.470671
1.3596	1.470614
1.37778	1.470558
1.39619	1.470502
1.41486	1.470447
1.43377	1.470392
1.45294	1.470338
1.47236	1.470285
1.49204	1.470232
1.51199	1.470179
1.5322	1.470126
1.55268	1.470074
1.57344	1.470023
1.59447	1.469971
1.61578	1.46992
1.63738	1.469869
1.65927	1.469818
1.68145	1.469767
1.70393	1.469716
1.7267	1.469665
1.74979	1.469614
1.77318	1.469563
1.79688	1.469512
1.8209	1.469461
1.84524	1.46941
1.86991	1.469358
1.8949	1.469307
1.92023	1.469255
1.9459	1.469202
1.97191	1.46915
1.99827	1.469097
2.02498	1.469043
2.05205	1.46899
2.07948	1.468935
2.10728	1.46888
2.13545	1.468825
2.164	1.468769
2.19292	1.468712
2.22224	1.468655
2.25194	1.468596
2.28205	1.468537
2.31255	1.468478
2.34347	1.468417
2.37479	1.468355
2.40654	1.468293
2.43871	1.468229
2.47131	1.468165
2.50434	1.468099
2.53782	1.468033
2.57174	1.467965
2.60612	1.467896
2.64096	1.467825
2.67626	1.467753
2.71204	1.46768
2.74829	1.467606
2.78503	1.46753
2.82226	1.467452
2.85998	1.467373
2.89821	1.467292
2.93696	1.46721
2.97622	1.467125
3.016	1.467039
3.05632	1.466951
3.09717	1.466861
3.13858	1.46677
3.18053	1.466675
3.22305	1.466579
3.26613	1.466481
3.30979	1.46638
3.35403	1.466277
3.39887	1.466172
3.4443	1.466064
3.49035	1.465953
3.537	1.46584
3.58428	1.465724
3.6322	1.465605
3.68075	1.465483
3.72995	1.465359
3.77981	1.465231
3.83034	1.4651
3.88154	1.464965
3.93343	1.464828
3.98601	1.464687
4.03929	1.464542
4.09329	1.464393
4.14801	1.464241
4.20345	1.464085
4.25964	1.463925
4.31659	1.463761
4.37429	1.463592
4.43276	1.463419
4.49202	1.463242
4.55206	1.46306
4.61291	1.462873
4.67458	1.462681
4.73706	1.462485
4.80039	1.462283
4.86456	1.462076
4.92958	1.461863
4.99548	1.461644
5.06226	1.46142
5.12993	1.46119
5.1985	1.460954
5.26799	1.460711
5.33841	1.460462
5.40978	1.460207
5.48209	1.459944
5.55537	1.459675
5.62963	1.459398
5.70489	1.459113
5.78115	1.458821
5.85843	1.458522
5.93674	1.458214
6.0161	1.457897
6.09652	1.457572
6.17802	1.457239
6.2606	1.456896
6.34429	1.456544
6.4291	1.456182
6.51504	1.455811
6.60213	1.455429
6.69038	1.455037
6.77982	1.454634
6.87045	1.45422
6.96229	1.453795
7.05536	1.453358
7.14967	1.452909
7.24524	1.452448
7.3421	1.451974
7.44024	1.451487
7.5397	1.450987
7.64049	1.450472
7.74262	1.449944
7.84612	1.449401
7.951	1.448842
8.05729	1.448269
8.165	1.447679
8.27414	1.447073
8.38475	1.44645
8.49683	1.44581
8.61041	1.445151
8.72551	1.444475
8.84215	1.443779
8.96035	1.443064
9.08013	1.442329
9.20151	1.441573
9.32451	1.440796
9.44915	1.439997
9.57547	1.439176
9.70347	1.438331
9.83318	1.437462
9.96462	1.436569
10.0978	1.43565
10.2328	1.434705
10.3696	1.433733
10.5082	1.432734
10.6487	1.431706
10.791	1.430648
10.9353	1.42956
11.0815	1.428441
11.2296	1.42729
11.3797	1.426105
11.5318	1.424886
11.686	1.423632
11.8422	1.422341
12.0005	1.421013
12.1609	1.419646
12.3235	1.41824
12.4882	1.416791
12.6551	1.415301
12.8243	1.413766
12.9957	1.412186
13.1695	1.41056
13.3455	1.408885
13.5239	1.40716
13.7047	1.405384
13.8879	1.403555
14.0735	1.401671
14.2616	1.39973
14.4523	1.39773
14.6455	1.39567
14.8413	1.393547
15.0396	1.39136
15.2407	1.389105
15.4444	1.386782
15.6509	1.384386
15.8601	1.381916
16.0721	1.37937
16.2869	1.376744
16.5047	1.374036
16.7253	1.371243
16.9489	1.368361
17.1754	1.365387
17.405	1.362319
17.6377	1.359153
17.8735	1.355884
18.1124	1.352509
18.3545	1.349025
18.5999	1.345426
18.8485	1.341709
19.1004	1.337868
19.3558	1.3339
19.6145	1.329798
19.8767	1.325558
20.1424	1.321174
20.4117	1.316639
20.6845	1.311949
20.961	1.307095
21.2412	1.302072
21.5252	1.296872
21.8129	1.291487
22.1045	1.285909
22.4	1.280129
22.6994	1.274138
23.0028	1.267927
23.3103	1.261485
23.6219	1.2548
23.9377	1.247863
24.2577	1.240659
24.582	1.233176
24.9106	1.225399
25.2435	1.217313
25.581	1.208903
25.9229	1.20015
26.2695	1.191035
26.6206	1.181539
26.9765	1.171639
27.3371	1.161312
27.7025	1.150531
28.0728	1.13927
28.4481	1.127498
28.8284	1.115181
29.2137	1.102283
29.6043	1.088765
30	1.074581

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: —

CsF (Cesium fluoride): all datasets

Li 1976: n 0.15–30 µm n 0.15–30 µm default

About CsF (Cesium fluoride)

Caesium fluoride (CsF) is an inorganic compound that forms colorless and highly hygroscopic crystals. This compound is known for its high solubility in water and other polar solvents. It is widely used as a source of fluoride ion in organic synthesis, often serving as a phase-transfer catalyst or as a base. In the realm of solid-state physics and materials science, CsF is studied for its interesting electrical and optical properties. Caesium fluoride is also employed in biochemistry and molecular biology for its ability to disrupt cell walls and facilitate the extraction of cellular materials. However, like other caesium compounds, CsF requires careful handling due to its reactivity and potential corrosive effects. Overexposure can lead to health risks, such as fluoride toxicity and imbalances in cellular ion channels. Thus, proper safety measures must be observed when working with this compound. Overall, CsF is a versatile material with applications ranging from organic synthesis to scientific research.

More about CsF (Cesium fluoride) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/main/CsF/nk/Li.yml
ID: ds_6e31f8be5019
API: /v1/datasets/ds_6e31f8be5019

Plot