Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.49772
Extinction coefficient k: 0

Permittivity ε₁: 2.24316
Permittivity ε₂: 0

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

Abbe number V_d: 66.273
Chromatic dispersion dn/dλ: -0.0375846 µm⁻¹

Group index n_g: 1.5198
Group velocity dispersion: 79.966 fs²/mm

Dispersion parameter D: -436.257 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

# Microchem 950 PMMA resist: Spec sheet: n 0.2–1.1 µm
microchem950 = ls.fetch_refractiveindex("other", "Microchem950", "specs", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(microchem950.range_nm)  # (200, 1100) nm
eps = microchem950.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_472c7ec504a1/lightsmith"
microchem950 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(microchem950.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (microchem950/specs).

# ... load microchem950 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=microchem950)],
    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"]).

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 = 1.488 + 0.002898 λ^{- 2.0} + 0.0001579 λ^{- 4.0}

Valid from 0.2 to 1.1 µm.

Coefficients as stored

C_i	Value
C1	1.488
C2	0.002898
C3	-2.0
C4	0.0001579
C5	-4.0

Comments and conditions

Microchem 950 PMMA resist

References

Microchem PMMA Datasheet, 2001

Cite

Microchem PMMA Datasheet, 2001; 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

Microchem 950 PMMA resist, Spec sheet: n 0.2–1.1 µm: n and k versus wavelength
λ (µm)	n
0.2	1.659137
0.200856	1.656849
0.201716	1.654594
0.20258	1.652372
0.203447	1.650182
0.204319	1.648025
0.205193	1.645899
0.206072	1.643804
0.206954	1.641739
0.20784	1.639705
0.20873	1.6377
0.209624	1.635725
0.210522	1.633778
0.211423	1.631859
0.212328	1.629969
0.213237	1.628105
0.21415	1.626269
0.215067	1.624459
0.215988	1.622675
0.216913	1.620917
0.217842	1.619185
0.218774	1.617477
0.219711	1.615794
0.220652	1.614135
0.221597	1.6125
0.222545	1.610888
0.223498	1.609299
0.224455	1.607733
0.225416	1.606189
0.226381	1.604668
0.227351	1.603168
0.228324	1.60169
0.229302	1.600232
0.230284	1.598795
0.23127	1.597379
0.23226	1.595983
0.233254	1.594606
0.234253	1.593249
0.235256	1.591911
0.236263	1.590592
0.237275	1.589291
0.238291	1.588009
0.239311	1.586745
0.240336	1.585499
0.241365	1.58427
0.242398	1.583058
0.243436	1.581864
0.244478	1.580686
0.245525	1.579524
0.246577	1.578379
0.247632	1.57725
0.248693	1.576136
0.249757	1.575038
0.250827	1.573955
0.251901	1.572887
0.252979	1.571834
0.254062	1.570795
0.25515	1.569771
0.256243	1.568761
0.25734	1.567765
0.258442	1.566782
0.259548	1.565814
0.26066	1.564858
0.261776	1.563915
0.262897	1.562986
0.264022	1.562069
0.265153	1.561164
0.266288	1.560272
0.267428	1.559393
0.268573	1.558525
0.269723	1.557669
0.270878	1.556824
0.272038	1.555991
0.273203	1.555169
0.274372	1.554359
0.275547	1.553559
0.276727	1.55277
0.277912	1.551992
0.279102	1.551224
0.280297	1.550467
0.281497	1.549719
0.282702	1.548982
0.283913	1.548255
0.285128	1.547537
0.286349	1.546829
0.287575	1.54613
0.288806	1.545441
0.290043	1.54476
0.291285	1.544089
0.292532	1.543427
0.293785	1.542773
0.295043	1.542129
0.296306	1.541492
0.297575	1.540864
0.298849	1.540245
0.300128	1.539633
0.301413	1.53903
0.302704	1.538434
0.304	1.537846
0.305302	1.537266
0.306609	1.536694
0.307922	1.536128
0.30924	1.535571
0.310564	1.53502
0.311894	1.534477
0.313229	1.533941
0.31457	1.533412
0.315917	1.532889
0.31727	1.532373
0.318628	1.531864
0.319993	1.531362
0.321363	1.530866
0.322739	1.530376
0.324121	1.529893
0.325508	1.529416
0.326902	1.528945
0.328302	1.52848
0.329708	1.528021
0.331119	1.527567
0.332537	1.52712
0.333961	1.526678
0.335391	1.526242
0.336827	1.525811
0.338269	1.525386
0.339717	1.524966
0.341172	1.524552
0.342633	1.524142
0.3441	1.523738
0.345573	1.523339
0.347053	1.522945
0.348539	1.522556
0.350031	1.522172
0.35153	1.521792
0.353035	1.521417
0.354546	1.521047
0.356064	1.520682
0.357589	1.520321
0.35912	1.519964
0.360658	1.519612
0.362202	1.519264
0.363753	1.518921
0.36531	1.518582
0.366874	1.518247
0.368445	1.517916
0.370023	1.517589
0.371607	1.517266
0.373198	1.516947
0.374796	1.516632
0.376401	1.516321
0.378013	1.516014
0.379631	1.51571
0.381257	1.51541
0.382889	1.515114
0.384528	1.514822
0.386175	1.514532
0.387828	1.514247
0.389489	1.513965
0.391157	1.513686
0.392831	1.51341
0.394513	1.513138
0.396203	1.512869
0.397899	1.512604
0.399603	1.512341
0.401314	1.512082
0.403032	1.511825
0.404758	1.511572
0.406491	1.511322
0.408231	1.511075
0.409979	1.510831
0.411734	1.510589
0.413497	1.510351
0.415268	1.510115
0.417046	1.509882
0.418832	1.509652
0.420625	1.509424
0.422426	1.509199
0.424235	1.508977
0.426051	1.508757
0.427875	1.50854
0.429707	1.508326
0.431547	1.508114
0.433395	1.507904
0.435251	1.507697
0.437114	1.507492
0.438986	1.50729
0.440865	1.50709
0.442753	1.506892
0.444649	1.506697
0.446553	1.506504
0.448465	1.506313
0.450385	1.506124
0.452313	1.505938
0.45425	1.505753
0.456195	1.505571
0.458148	1.505391
0.46011	1.505212
0.46208	1.505036
0.464058	1.504862
0.466045	1.50469
0.468041	1.50452
0.470045	1.504351
0.472057	1.504185
0.474078	1.50402
0.476108	1.503858
0.478147	1.503697
0.480194	1.503538
0.48225	1.50338
0.484315	1.503225
0.486389	1.503071
0.488471	1.502919
0.490563	1.502769
0.492663	1.50262
0.494773	1.502473
0.496891	1.502328
0.499019	1.502184
0.501155	1.502042
0.503301	1.501901
0.505456	1.501762
0.50762	1.501625
0.509794	1.501489
0.511976	1.501354
0.514169	1.501221
0.51637	1.50109
0.518581	1.500959
0.520801	1.500831
0.523031	1.500704
0.525271	1.500578
0.52752	1.500453
0.529779	1.50033
0.532047	1.500208
0.534325	1.500088
0.536613	1.499968
0.53891	1.499851
0.541218	1.499734
0.543535	1.499619
0.545862	1.499504
0.5482	1.499392
0.550547	1.49928
0.552904	1.499169
0.555272	1.49906
0.557649	1.498952
0.560037	1.498845
0.562435	1.498739
0.564843	1.498635
0.567261	1.498531
0.56969	1.498428
0.572129	1.498327
0.574579	1.498227
0.577039	1.498128
0.57951	1.498029
0.581991	1.497932
0.584483	1.497836
0.586986	1.497741
0.589499	1.497647
0.592023	1.497554
0.594558	1.497462
0.597104	1.49737
0.59966	1.49728
0.602228	1.497191
0.604806	1.497103
0.607396	1.497015
0.609997	1.496929
0.612608	1.496843
0.615231	1.496758
0.617866	1.496675
0.620511	1.496592
0.623168	1.49651
0.625836	1.496428
0.628516	1.496348
0.631207	1.496268
0.63391	1.49619
0.636624	1.496112
0.63935	1.496035
0.642087	1.495958
0.644836	1.495883
0.647597	1.495808
0.65037	1.495734
0.653155	1.495661
0.655951	1.495588
0.65876	1.495516
0.661581	1.495445
0.664413	1.495375
0.667258	1.495305
0.670115	1.495237
0.672984	1.495168
0.675866	1.495101
0.67876	1.495034
0.681666	1.494968
0.684585	1.494903
0.687516	1.494838
0.69046	1.494774
0.693416	1.49471
0.696385	1.494647
0.699367	1.494585
0.702361	1.494523
0.705368	1.494462
0.708388	1.494402
0.711422	1.494342
0.714468	1.494283
0.717527	1.494225
0.720599	1.494167
0.723684	1.494109
0.726783	1.494052
0.729895	1.493996
0.73302	1.49394
0.736159	1.493885
0.739311	1.493831
0.742476	1.493777
0.745655	1.493723
0.748848	1.49367
0.752054	1.493618
0.755274	1.493566
0.758508	1.493514
0.761756	1.493463
0.765017	1.493413
0.768293	1.493363
0.771583	1.493313
0.774886	1.493264
0.778204	1.493216
0.781536	1.493168
0.784882	1.49312
0.788243	1.493073
0.791618	1.493027
0.795007	1.49298
0.798411	1.492935
0.80183	1.492889
0.805263	1.492845
0.808711	1.4928
0.812174	1.492756
0.815651	1.492713
0.819144	1.49267
0.822651	1.492627
0.826173	1.492585
0.829711	1.492543
0.833263	1.492501
0.836831	1.49246
0.840414	1.49242
0.844012	1.492379
0.847626	1.492339
0.851256	1.4923
0.8549	1.492261
0.858561	1.492222
0.862237	1.492184
0.865929	1.492146
0.869636	1.492108
0.87336	1.492071
0.877099	1.492034
0.880855	1.491997
0.884626	1.491961
0.888414	1.491925
0.892218	1.49189
0.896038	1.491854
0.899875	1.49182
0.903728	1.491785
0.907597	1.491751
0.911483	1.491717
0.915386	1.491683
0.919305	1.49165
0.923241	1.491617
0.927195	1.491585
0.931164	1.491552
0.935151	1.49152
0.939155	1.491489
0.943177	1.491457
0.947215	1.491426
0.951271	1.491395
0.955344	1.491365
0.959434	1.491335
0.963542	1.491305
0.967668	1.491275
0.971811	1.491246
0.975972	1.491216
0.980151	1.491188
0.984348	1.491159
0.988562	1.491131
0.992795	1.491103
0.997046	1.491075
1.00131	1.491047
1.0056	1.49102
1.00991	1.490993
1.01423	1.490966
1.01857	1.49094
1.02294	1.490914
1.02732	1.490888
1.03171	1.490862
1.03613	1.490836
1.04057	1.490811
1.04502	1.490786
1.0495	1.490761
1.05399	1.490737
1.0585	1.490712
1.06304	1.490688
1.06759	1.490664
1.07216	1.490641
1.07675	1.490617
1.08136	1.490594
1.08599	1.490571
1.09064	1.490548
1.09531	1.490525
1.1	1.490503

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: —

Plot