Optical constants

Refractive index of C₈H₁₆O₂ (Caprylic acid)

Rubio et al. 2015: n 0.400–0.590 µm

Data: formula 5
Range: 0.4–0.59 µm
Temperature: 293.15 K
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.4283
Extinction coefficient k: 0

Permittivity ε₁: 2.04003
Permittivity ε₂: 0

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

Abbe number V_d: —
Chromatic dispersion dn/dλ: -0.0385808 µm⁻¹

Group index n_g: 1.45097
Group velocity dispersion: 70.7677 fs²/mm

Dispersion parameter D: -386.076 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

# C8H16O2 (Caprylic acid): Rubio et al. 2015: n 0.400–0.590 µm
c8h16o2 = ls.fetch_refractiveindex("organic", "caprylic_acid", "Rubio", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(c8h16o2.range_nm)  # (400, 590) nm
eps = c8h16o2.eps([486])  # 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_c603282fe15d/lightsmith"
c8h16o2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(c8h16o2.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (caprylic-acid/rubio-2015).

# ... load c8h16o2 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=c8h16o2)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=590, 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"]).

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

Cauchy (formula 5), λ in µm

n = 1.41696 + 0.00391369 λ^{- 2.0}

Valid from 0.4 to 0.59 µm.

Coefficients as stored

C_i	Value
C1	1.41696
C2	0.00391369
C3	-2.0

Comments and conditions

20 °C (293.15 K). For the temperature-dependent formula, refer to the original publication.

Conditions

temperature: 293.15 K

References

J. E. F. Rubio, J. M. Arsuaga, M. Taravillo, M. Cáceres. Refractive index temperature and wavelength dependencies of normal saturated fatty acids in liquid state. Exp. Therm. Fluid Sci. 29, 681-684 (2015)

doi:10.1016/j.expthermflusci.2004.11.002 Refractive index temperature and wavelength dependencies of normal saturated fatty acids in liquid state, Experimental Thermal and Fluid Science (2005)

Cite

José E.F. Rubio, Jesús M. Arsuaga, Mercedes Taravillo and Mercedes Cáceres. Refractive index temperature and wavelength dependencies of normal saturated fatty acids in liquid state. Experimental Thermal and Fluid Science, 29, 681-684 (2005), doi:10.1016/j.expthermflusci.2004.11.002; 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

C8H16O2 (Caprylic acid), Rubio et al. 2015: n 0.400–0.590 µm: n and k versus wavelength
λ (µm)	n
0.4	1.441421
0.40039	1.441373
0.40078	1.441325
0.401171	1.441278
0.401562	1.441231
0.401953	1.441183
0.402345	1.441136
0.402737	1.441089
0.403129	1.441042
0.403522	1.440995
0.403915	1.440949
0.404309	1.440902
0.404703	1.440855
0.405097	1.440809
0.405492	1.440762
0.405887	1.440716
0.406283	1.44067
0.406679	1.440624
0.407075	1.440578
0.407472	1.440532
0.407869	1.440486
0.408267	1.44044
0.408664	1.440394
0.409063	1.440349
0.409461	1.440303
0.40986	1.440258
0.41026	1.440212
0.41066	1.440167
0.41106	1.440122
0.41146	1.440077
0.411861	1.440032
0.412263	1.439987
0.412665	1.439942
0.413067	1.439897
0.413469	1.439853
0.413872	1.439808
0.414276	1.439764
0.414679	1.439719
0.415083	1.439675
0.415488	1.439631
0.415893	1.439587
0.416298	1.439543
0.416704	1.439499
0.41711	1.439455
0.417517	1.439411
0.417923	1.439367
0.418331	1.439324
0.418738	1.43928
0.419146	1.439237
0.419555	1.439194
0.419964	1.43915
0.420373	1.439107
0.420783	1.439064
0.421193	1.439021
0.421603	1.438978
0.422014	1.438935
0.422425	1.438892
0.422837	1.43885
0.423249	1.438807
0.423662	1.438765
0.424075	1.438722
0.424488	1.43868
0.424902	1.438638
0.425316	1.438595
0.42573	1.438553
0.426145	1.438511
0.42656	1.438469
0.426976	1.438427
0.427392	1.438386
0.427809	1.438344
0.428226	1.438302
0.428643	1.438261
0.429061	1.438219
0.429479	1.438178
0.429897	1.438137
0.430316	1.438095
0.430736	1.438054
0.431155	1.438013
0.431576	1.437972
0.431996	1.437931
0.432417	1.437891
0.432839	1.43785
0.43326	1.437809
0.433683	1.437769
0.434105	1.437728
0.434528	1.437688
0.434952	1.437647
0.435376	1.437607
0.4358	1.437567
0.436225	1.437527
0.43665	1.437487
0.437075	1.437447
0.437501	1.437407
0.437928	1.437367
0.438355	1.437327
0.438782	1.437288
0.439209	1.437248
0.439637	1.437209
0.440066	1.437169
0.440495	1.43713
0.440924	1.437091
0.441354	1.437052
0.441784	1.437012
0.442214	1.436973
0.442645	1.436934
0.443077	1.436896
0.443509	1.436857
0.443941	1.436818
0.444373	1.436779
0.444806	1.436741
0.44524	1.436702
0.445674	1.436664
0.446108	1.436626
0.446543	1.436587
0.446978	1.436549
0.447414	1.436511
0.44785	1.436473
0.448286	1.436435
0.448723	1.436397
0.44916	1.436359
0.449598	1.436321
0.450036	1.436284
0.450475	1.436246
0.450914	1.436209
0.451353	1.436171
0.451793	1.436134
0.452234	1.436096
0.452674	1.436059
0.453115	1.436022
0.453557	1.435985
0.453999	1.435948
0.454441	1.435911
0.454884	1.435874
0.455328	1.435837
0.455771	1.4358
0.456216	1.435764
0.45666	1.435727
0.457105	1.435691
0.457551	1.435654
0.457997	1.435618
0.458443	1.435582
0.45889	1.435545
0.459337	1.435509
0.459785	1.435473
0.460233	1.435437
0.460681	1.435401
0.46113	1.435365
0.46158	1.435329
0.462029	1.435294
0.46248	1.435258
0.46293	1.435222
0.463381	1.435187
0.463833	1.435151
0.464285	1.435116
0.464738	1.435081
0.46519	1.435045
0.465644	1.43501
0.466098	1.434975
0.466552	1.43494
0.467007	1.434905
0.467462	1.43487
0.467917	1.434835
0.468373	1.4348
0.46883	1.434766
0.469287	1.434731
0.469744	1.434696
0.470202	1.434662
0.47066	1.434627
0.471119	1.434593
0.471578	1.434559
0.472037	1.434524
0.472497	1.43449
0.472958	1.434456
0.473419	1.434422
0.47388	1.434388
0.474342	1.434354
0.474804	1.43432
0.475267	1.434287
0.47573	1.434253
0.476194	1.434219
0.476658	1.434186
0.477122	1.434152
0.477587	1.434119
0.478053	1.434085
0.478519	1.434052
0.478985	1.434019
0.479452	1.433985
0.479919	1.433952
0.480387	1.433919
0.480855	1.433886
0.481324	1.433853
0.481793	1.43382
0.482262	1.433788
0.482732	1.433755
0.483203	1.433722
0.483674	1.433689
0.484145	1.433657
0.484617	1.433624
0.485089	1.433592
0.485562	1.43356
0.486035	1.433527
0.486509	1.433495
0.486983	1.433463
0.487457	1.433431
0.487932	1.433399
0.488408	1.433367
0.488884	1.433335
0.48936	1.433303
0.489837	1.433271
0.490315	1.433239
0.490792	1.433208
0.491271	1.433176
0.49175	1.433144
0.492229	1.433113
0.492708	1.433082
0.493189	1.43305
0.493669	1.433019
0.49415	1.432988
0.494632	1.432956
0.495114	1.432925
0.495597	1.432894
0.49608	1.432863
0.496563	1.432832
0.497047	1.432801
0.497531	1.43277
0.498016	1.43274
0.498502	1.432709
0.498987	1.432678
0.499474	1.432648
0.49996	1.432617
0.500448	1.432587
0.500935	1.432556
0.501424	1.432526
0.501912	1.432496
0.502401	1.432465
0.502891	1.432435
0.503381	1.432405
0.503872	1.432375
0.504363	1.432345
0.504854	1.432315
0.505346	1.432285
0.505839	1.432255
0.506332	1.432226
0.506825	1.432196
0.507319	1.432166
0.507813	1.432137
0.508308	1.432107
0.508804	1.432078
0.5093	1.432048
0.509796	1.432019
0.510293	1.43199
0.51079	1.43196
0.511288	1.431931
0.511786	1.431902
0.512285	1.431873
0.512784	1.431844
0.513284	1.431815
0.513784	1.431786
0.514285	1.431757
0.514786	1.431728
0.515288	1.4317
0.51579	1.431671
0.516293	1.431642
0.516796	1.431614
0.517299	1.431585
0.517803	1.431557
0.518308	1.431528
0.518813	1.4315
0.519319	1.431472
0.519825	1.431443
0.520332	1.431415
0.520839	1.431387
0.521346	1.431359
0.521854	1.431331
0.522363	1.431303
0.522872	1.431275
0.523382	1.431247
0.523892	1.431219
0.524402	1.431192
0.524913	1.431164
0.525425	1.431136
0.525937	1.431109
0.526449	1.431081
0.526962	1.431054
0.527476	1.431026
0.52799	1.430999
0.528505	1.430972
0.52902	1.430944
0.529535	1.430917
0.530051	1.43089
0.530568	1.430863
0.531085	1.430836
0.531602	1.430809
0.532121	1.430782
0.532639	1.430755
0.533158	1.430728
0.533678	1.430701
0.534198	1.430675
0.534718	1.430648
0.53524	1.430621
0.535761	1.430595
0.536283	1.430568
0.536806	1.430542
0.537329	1.430515
0.537853	1.430489
0.538377	1.430462
0.538902	1.430436
0.539427	1.43041
0.539953	1.430384
0.540479	1.430358
0.541005	1.430332
0.541533	1.430306
0.54206	1.43028
0.542589	1.430254
0.543118	1.430228
0.543647	1.430202
0.544177	1.430176
0.544707	1.43015
0.545238	1.430125
0.545769	1.430099
0.546301	1.430074
0.546833	1.430048
0.547366	1.430023
0.5479	1.429997
0.548434	1.429972
0.548968	1.429946
0.549503	1.429921
0.550039	1.429896
0.550575	1.429871
0.551111	1.429846
0.551648	1.429821
0.552186	1.429796
0.552724	1.429771
0.553263	1.429746
0.553802	1.429721
0.554342	1.429696
0.554882	1.429671
0.555423	1.429646
0.555964	1.429622
0.556506	1.429597
0.557048	1.429572
0.557591	1.429548
0.558134	1.429523
0.558678	1.429499
0.559223	1.429475
0.559768	1.42945
0.560313	1.429426
0.560859	1.429402
0.561406	1.429377
0.561953	1.429353
0.562501	1.429329
0.563049	1.429305
0.563598	1.429281
0.564147	1.429257
0.564697	1.429233
0.565247	1.429209
0.565798	1.429185
0.566349	1.429162
0.566901	1.429138
0.567454	1.429114
0.568007	1.429091
0.56856	1.429067
0.569114	1.429043
0.569669	1.42902
0.570224	1.428996
0.57078	1.428973
0.571336	1.42895
0.571893	1.428926
0.57245	1.428903
0.573008	1.42888
0.573567	1.428856
0.574126	1.428833
0.574685	1.42881
0.575245	1.428787
0.575806	1.428764
0.576367	1.428741
0.576929	1.428718
0.577491	1.428695
0.578054	1.428673
0.578617	1.42865
0.579181	1.428627
0.579745	1.428604
0.58031	1.428582
0.580876	1.428559
0.581442	1.428536
0.582009	1.428514
0.582576	1.428491
0.583144	1.428469
0.583712	1.428447
0.584281	1.428424
0.58485	1.428402
0.58542	1.42838
0.585991	1.428357
0.586562	1.428335
0.587133	1.428313
0.587706	1.428291
0.588278	1.428269
0.588852	1.428247
0.589426	1.428225
0.59	1.428203

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: —

C₈H₁₆O₂ (Caprylic acid): all datasets

Rubio et al. 2015: n 0.400–0.590 µm n 0.4–0.59 µm default

About C8H16O2 (Caprylic acid)

Caprylic acid is a saturated medium-chain fatty acid with an eight-carbon backbone. It is a colorless to pale yellow liquid with a slightly unpleasant, rancid odor. Found naturally in coconut oil and palm kernel oil, caprylic acid is used in the production of perfumes, dyes, and in the treatment of some bacterial and yeast infections due to its antimicrobial properties. It also serves as a dietary supplement promoting digestive health. Chemical formula: CH₃(CH₂)₆COOH

More about C8H16O2 (Caprylic acid) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/organic/C8H16O2 - caprylic acid/nk/Rubio.yml
ID: ds_c603282fe15d
API: /v1/datasets/ds_c603282fe15d

Plot