Optical constants

Refractive index of C₇H₈ (Toluene)

Kozma et al. 2005: n 0.300–0.641 µm

Data: formula 5
Range: 0.3001–0.6407 µm
Temperature: 295 K
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.49644
Extinction coefficient k: 0

Permittivity ε₁: 2.23932
Permittivity ε₂: 0

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

Abbe number V_d: —
Chromatic dispersion dn/dλ: -0.0615384 µm⁻¹

Group index n_g: 1.5326
Group velocity dispersion: 141.783 fs²/mm

Dispersion parameter D: -773.503 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

# C7H8 (Toluene): Kozma et al. 2005: n 0.300–0.641 µm
c7h8 = ls.fetch_refractiveindex("organic", "toluene", "Kozma", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(c7h8.range_nm)  # (300.1, 640.7) nm
eps = c7h8.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_530bdddee019/lightsmith"
c7h8 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(c7h8.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (toluene/kozma-2005).

# ... load c7h8 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=c7h8)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=640, 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 = 1.4815 + 0.004186 λ^{- 2.0} + 0.000296117366 λ^{- 4.0} + 1.3562 \times 10^{-5} λ^{- 6.0}

Valid from 0.3001 to 0.6407 µm.

Coefficients as stored

C_i	Value
C1	1.4815
C2	0.004186
C3	-2.0
C4	0.000296117366
C5	-4.0
C6	1.3562e-05
C7	-6.0

Comments and conditions

22 °C.

Conditions

temperature: 295 K

References

I. Z. Kozma, P. Krok, E. Riedle. Direct measurement of the group-velocity mismatch and derivation of the refractive-index dispersion for a variety of solvents in the ultraviolet. J. Opt. Soc. Am. B 22, 1479-1485 (2005)

doi:10.1364/josab.22.001479 Direct measurement of the group-velocity mismatch and derivation of the refractive-index dispersion for a variety of solvents in the ultraviolet, Journal of the Optical Society of America B (2005)

Cite

Ida Z. Kozma, Patrizia Krok and Eberhard Riedle. Direct measurement of the group-velocity mismatch and derivation of the refractive-index dispersion for a variety of solvents in the ultraviolet. Journal of the Optical Society of America B, 22, 1479 (2005), doi:10.1364/josab.22.001479; 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

C7H8 (Toluene), Kozma et al. 2005: n 0.300–0.641 µm: n and k versus wavelength
λ (µm)	n
0.3001	1.583056
0.300671	1.582392
0.301243	1.581734
0.301816	1.581081
0.30239	1.580432
0.302966	1.579789
0.303542	1.579151
0.30412	1.578518
0.304698	1.57789
0.305278	1.577266
0.305859	1.576647
0.306441	1.576033
0.307024	1.575424
0.307608	1.57482
0.308194	1.57422
0.30878	1.573624
0.309367	1.573034
0.309956	1.572447
0.310546	1.571866
0.311137	1.571288
0.311729	1.570715
0.312322	1.570147
0.312916	1.569582
0.313511	1.569022
0.314108	1.568467
0.314706	1.567915
0.315304	1.567368
0.315904	1.566825
0.316505	1.566285
0.317108	1.56575
0.317711	1.565219
0.318315	1.564692
0.318921	1.564169
0.319528	1.56365
0.320136	1.563135
0.320745	1.562623
0.321355	1.562116
0.321967	1.561612
0.322579	1.561112
0.323193	1.560616
0.323808	1.560123
0.324424	1.559634
0.325041	1.559149
0.32566	1.558667
0.326279	1.558189
0.3269	1.557714
0.327522	1.557243
0.328145	1.556776
0.32877	1.556312
0.329395	1.555851
0.330022	1.555394
0.33065	1.55494
0.331279	1.554489
0.331909	1.554042
0.332541	1.553598
0.333174	1.553157
0.333807	1.552719
0.334443	1.552285
0.335079	1.551854
0.335716	1.551426
0.336355	1.551001
0.336995	1.550579
0.337636	1.55016
0.338279	1.549744
0.338922	1.549332
0.339567	1.548922
0.340213	1.548515
0.340861	1.548111
0.341509	1.54771
0.342159	1.547312
0.34281	1.546917
0.343462	1.546525
0.344116	1.546135
0.34477	1.545749
0.345426	1.545365
0.346084	1.544983
0.346742	1.544605
0.347402	1.544229
0.348063	1.543856
0.348725	1.543486
0.349389	1.543118
0.350053	1.542753
0.35072	1.54239
0.351387	1.54203
0.352055	1.541673
0.352725	1.541318
0.353396	1.540965
0.354069	1.540615
0.354742	1.540268
0.355417	1.539923
0.356094	1.53958
0.356771	1.53924
0.35745	1.538902
0.35813	1.538567
0.358811	1.538234
0.359494	1.537903
0.360178	1.537574
0.360863	1.537248
0.36155	1.536924
0.362238	1.536603
0.362927	1.536283
0.363618	1.535966
0.36431	1.535651
0.365003	1.535338
0.365697	1.535028
0.366393	1.534719
0.36709	1.534413
0.367789	1.534109
0.368488	1.533807
0.36919	1.533506
0.369892	1.533208
0.370596	1.532913
0.371301	1.532619
0.372007	1.532327
0.372715	1.532037
0.373424	1.531749
0.374135	1.531463
0.374847	1.531179
0.37556	1.530897
0.376274	1.530617
0.37699	1.530338
0.377708	1.530062
0.378426	1.529787
0.379146	1.529515
0.379868	1.529244
0.380591	1.528975
0.381315	1.528708
0.38204	1.528442
0.382767	1.528179
0.383495	1.527917
0.384225	1.527657
0.384956	1.527399
0.385689	1.527142
0.386422	1.526887
0.387158	1.526634
0.387894	1.526383
0.388632	1.526133
0.389372	1.525885
0.390113	1.525638
0.390855	1.525393
0.391598	1.52515
0.392344	1.524908
0.39309	1.524668
0.393838	1.52443
0.394587	1.524193
0.395338	1.523958
0.39609	1.523724
0.396844	1.523492
0.397599	1.523261
0.398355	1.523032
0.399113	1.522804
0.399873	1.522578
0.400634	1.522354
0.401396	1.52213
0.40216	1.521909
0.402925	1.521688
0.403691	1.521469
0.40446	1.521252
0.405229	1.521036
0.406	1.520821
0.406773	1.520608
0.407547	1.520396
0.408322	1.520186
0.409099	1.519977
0.409877	1.519769
0.410657	1.519562
0.411438	1.519357
0.412221	1.519153
0.413006	1.518951
0.413791	1.51875
0.414579	1.51855
0.415368	1.518351
0.416158	1.518154
0.41695	1.517958
0.417743	1.517763
0.418538	1.517569
0.419334	1.517377
0.420132	1.517186
0.420931	1.516996
0.421732	1.516807
0.422535	1.516619
0.423339	1.516433
0.424144	1.516248
0.424951	1.516064
0.42576	1.515881
0.42657	1.515699
0.427381	1.515519
0.428195	1.515339
0.429009	1.515161
0.429826	1.514984
0.430643	1.514808
0.431463	1.514633
0.432284	1.514459
0.433106	1.514286
0.43393	1.514114
0.434756	1.513944
0.435583	1.513774
0.436412	1.513606
0.437242	1.513438
0.438074	1.513272
0.438908	1.513106
0.439743	1.512942
0.440579	1.512778
0.441418	1.512616
0.442258	1.512455
0.443099	1.512294
0.443942	1.512135
0.444787	1.511976
0.445633	1.511819
0.446481	1.511662
0.44733	1.511507
0.448182	1.511352
0.449034	1.511199
0.449889	1.511046
0.450745	1.510894
0.451602	1.510743
0.452462	1.510593
0.453322	1.510444
0.454185	1.510296
0.455049	1.510149
0.455915	1.510003
0.456782	1.509857
0.457652	1.509713
0.458522	1.509569
0.459395	1.509426
0.460269	1.509284
0.461145	1.509143
0.462022	1.509003
0.462901	1.508863
0.463782	1.508725
0.464664	1.508587
0.465548	1.50845
0.466434	1.508314
0.467322	1.508178
0.468211	1.508044
0.469102	1.50791
0.469994	1.507777
0.470888	1.507645
0.471784	1.507514
0.472682	1.507383
0.473581	1.507253
0.474482	1.507124
0.475385	1.506996
0.47629	1.506868
0.477196	1.506742
0.478104	1.506616
0.479014	1.50649
0.479925	1.506366
0.480838	1.506242
0.481753	1.506119
0.48267	1.505996
0.483588	1.505875
0.484508	1.505754
0.48543	1.505634
0.486354	1.505514
0.487279	1.505395
0.488206	1.505277
0.489135	1.505159
0.490066	1.505043
0.490998	1.504927
0.491932	1.504811
0.492868	1.504696
0.493806	1.504582
0.494746	1.504469
0.495687	1.504356
0.49663	1.504244
0.497575	1.504132
0.498522	1.504021
0.49947	1.503911
0.50042	1.503801
0.501373	1.503692
0.502327	1.503584
0.503282	1.503476
0.50424	1.503369
0.505199	1.503263
0.506161	1.503157
0.507124	1.503051
0.508089	1.502947
0.509055	1.502843
0.510024	1.502739
0.510994	1.502636
0.511966	1.502534
0.512941	1.502432
0.513917	1.502331
0.514894	1.50223
0.515874	1.50213
0.516856	1.502031
0.517839	1.501932
0.518824	1.501833
0.519811	1.501735
0.5208	1.501638
0.521791	1.501541
0.522784	1.501445
0.523779	1.501349
0.524775	1.501254
0.525774	1.50116
0.526774	1.501065
0.527777	1.500972
0.528781	1.500879
0.529787	1.500786
0.530795	1.500694
0.531805	1.500603
0.532817	1.500512
0.53383	1.500421
0.534846	1.500331
0.535864	1.500242
0.536883	1.500153
0.537905	1.500064
0.538928	1.499976
0.539954	1.499889
0.540981	1.499802
0.54201	1.499715
0.543042	1.499629
0.544075	1.499543
0.54511	1.499458
0.546147	1.499373
0.547186	1.499289
0.548227	1.499205
0.549271	1.499122
0.550316	1.499039
0.551363	1.498957
0.552412	1.498875
0.553463	1.498793
0.554516	1.498712
0.555571	1.498631
0.556628	1.498551
0.557687	1.498471
0.558748	1.498392
0.559811	1.498313
0.560876	1.498234
0.561944	1.498156
0.563013	1.498079
0.564084	1.498001
0.565157	1.497925
0.566233	1.497848
0.56731	1.497772
0.568389	1.497696
0.569471	1.497621
0.570554	1.497546
0.57164	1.497472
0.572728	1.497398
0.573817	1.497324
0.574909	1.497251
0.576003	1.497178
0.577099	1.497106
0.578197	1.497034
0.579297	1.496962
0.580399	1.496891
0.581504	1.49682
0.58261	1.496749
0.583719	1.496679
0.584829	1.496609
0.585942	1.49654
0.587057	1.496471
0.588174	1.496402
0.589293	1.496333
0.590414	1.496265
0.591537	1.496198
0.592663	1.496131
0.593791	1.496064
0.59492	1.495997
0.596052	1.495931
0.597186	1.495865
0.598323	1.495799
0.599461	1.495734
0.600602	1.495669
0.601744	1.495605
0.602889	1.49554
0.604036	1.495477
0.605186	1.495413
0.606337	1.49535
0.607491	1.495287
0.608647	1.495224
0.609805	1.495162
0.610965	1.4951
0.612127	1.495038
0.613292	1.494977
0.614459	1.494916
0.615628	1.494856
0.616799	1.494795
0.617973	1.494735
0.619149	1.494675
0.620327	1.494616
0.621507	1.494557
0.62269	1.494498
0.623874	1.49444
0.625062	1.494381
0.626251	1.494323
0.627442	1.494266
0.628636	1.494208
0.629832	1.494151
0.631031	1.494095
0.632231	1.494038
0.633434	1.493982
0.634639	1.493926
0.635847	1.49387
0.637057	1.493815
0.638269	1.49376
0.639483	1.493705
0.6407	1.493651

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: —

C₇H₈ (Toluene): all datasets

About C7H8 (Toluene)

Toluene (C₇H₈) is a clear, colorless liquid with a distinctive, pungent odor reminiscent of paint thinners. It is a naturally occurring hydrocarbon, found at low concentrations in crude oil and is a major component of gasoline. Toluene is widely used as an industrial solvent for paints, coatings, adhesives, and other applications. Furthermore, it serves as an important precursor in the synthesis of a variety of chemicals, especially benzene, xylenes, and a range of polymers and resins. Due to its refractive qualities, it can be of interest in optical studies. While it has various industrial and chemical applications, toluene is also known to have neurotoxic effects and can be harmful if inhaled in large quantities. Proper care should be taken when working with this compound.

More about C7H8 (Toluene) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/organic/C7H8 - toluene/nk/Kozma.yml
ID: ds_530bdddee019
API: /v1/datasets/ds_530bdddee019

Plot