Optical constants

Refractive index of D-LAF79 (CDGM)

D-LAF79: n,k 0.365–2.325 µm

Data: formula 2 + tabulated k
Range: 0.365–2.325 µm
Temperature: 293 K
Licence: CC0-1.0

Axis Log x Log y

Click the plot to set the calculator wavelength.

At one wavelength

Refractive index n: 1.73077
Extinction coefficient k: 2.45299e-08

Permittivity ε₁: 2.99555
Permittivity ε₂: 8.49112e-08

Absorption coefficient α: 0.00524595 cm⁻¹
Penetration depth δ = λ/(2πk): 3.81246e+09 nm

Abbe number V_d: 40.508
Chromatic dispersion dn/dλ: -0.0919586 µm⁻¹

Group index n_g: 1.7848
Group velocity dispersion: 173.719 fs²/mm

Dispersion parameter D: -947.728 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

# D-LAF79 (CDGM): D-LAF79
cdgm_d_laf79 = ls.fetch_refractiveindex("specs", "CDGM-optical", "D-LAF79", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(cdgm_d_laf79.range_nm)  # (365, 2325) nm
eps = cdgm_d_laf79.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_e2799131aea8/lightsmith"
cdgm_d_laf79 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(cdgm_d_laf79.source)  # citation and provenance travel with the data

Any dataset here, as the library's Tabulated material (cdgm-d-laf79/cdgm).

# ... load cdgm_d_laf79 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=cdgm_d_laf79)],
    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_e2799131aea8/lightsmith?model=drude_lorentz"
cdgm_d_laf79_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 = \frac{0.26530456 λ^{2}}{λ^{2} - 0.0420844203} + \frac{1.45255299 λ^{2}}{λ^{2} - 117.349274} + \frac{1.65170478 λ^{2}}{λ^{2} - 0.00935611552}

Valid from 0.365 to 2.325 µm.

Coefficients as stored

C_i	Value
C1	0.0
C2	0.26530456
C3	0.0420844203
C4	1.45255299
C5	117.349274
C6	1.65170478
C7	0.00935611552

Comments and conditions

anneal rate:4°C/h

Conditions

temperature: 293 K

Properties

nd: 1.730770
Vd: 40.508021
glass code: 731405
density: value: 3210
thermal expansion: value: 9e-06, temperature range: 243 343; value: 1.11e-05, temperature range: 293 573
dPgF: -0.0047
resistance: climatic: 3.0

References

CDGM Zemax catalog 2022-06 (obtained from http://www.cdgmgd.com)
See also CDGM optical glass data sheets

Cite

CDGM Zemax catalog 2022-06 (obtained from http://www.cdgmgd.com); See also CDGM optical glass data sheets; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 425 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

D-LAF79 (CDGM), D-LAF79: n and k versus wavelength
λ (µm)	n	k
0.365	1.778376	8.809100e-07
0.366698	1.77756	8.048888e-07
0.368403	1.776755	7.285140e-07
0.37	1.776016	6.570200e-07
0.370117	1.775962	6.545063e-07
0.371838	1.77518	6.174984e-07
0.373568	1.774408	5.803184e-07
0.375306	1.773647	5.429655e-07
0.377051	1.772897	5.054388e-07
0.378805	1.772157	4.677376e-07
0.38	1.77166	4.420500e-07
0.380567	1.771426	4.343568e-07
0.382337	1.770706	4.103395e-07
0.384116	1.769995	3.862105e-07
0.385902	1.769293	3.619693e-07
0.387697	1.768601	3.376153e-07
0.3895	1.767918	3.131480e-07
0.39	1.767731	3.063700e-07
0.391312	1.767244	2.942406e-07
0.393132	1.766578	2.774154e-07
0.394961	1.765922	2.605119e-07
0.396798	1.765273	2.435298e-07
0.398644	1.764634	2.264688e-07
0.4	1.76417	2.139300e-07
0.400498	1.764002	2.119146e-07
0.402361	1.763378	2.043729e-07
0.404232	1.762763	1.967961e-07
0.406112	1.762155	1.891840e-07
0.408001	1.761554	1.815366e-07
0.409899	1.760962	1.738535e-07
0.411806	1.760376	1.661348e-07
0.413721	1.759798	1.583801e-07
0.415645	1.759227	1.505893e-07
0.417579	1.758664	1.427624e-07
0.419521	1.758107	1.348990e-07
0.42	1.757971	1.329600e-07
0.421472	1.757556	1.304921e-07
0.423433	1.757013	1.272063e-07
0.425402	1.756476	1.239052e-07
0.427381	1.755946	1.205887e-07
0.429369	1.755422	1.172568e-07
0.431366	1.754904	1.139094e-07
0.433372	1.754393	1.105464e-07
0.435388	1.753887	1.071678e-07
0.437413	1.753388	1.037735e-07
0.439448	1.752894	1.003633e-07
0.44	1.752762	9.943800e-08
0.441492	1.752407	9.753690e-08
0.443545	1.751925	9.492020e-08
0.445609	1.751449	9.229132e-08
0.447681	1.750978	8.965022e-08
0.449764	1.750512	8.699683e-08
0.451856	1.750053	8.433110e-08
0.453957	1.749598	8.165298e-08
0.456069	1.749149	7.896239e-08
0.45819	1.748704	7.625929e-08
0.46	1.748331	7.395300e-08
0.460321	1.748265	7.363014e-08
0.462462	1.747831	7.147843e-08
0.464613	1.747402	6.931672e-08
0.466775	1.746977	6.714495e-08
0.468946	1.746558	6.496308e-08
0.471127	1.746143	6.277106e-08
0.473318	1.745733	6.056885e-08
0.47552	1.745327	5.835639e-08
0.477732	1.744926	5.613364e-08
0.479954	1.744529	5.390056e-08
0.48	1.744521	5.385400e-08
0.482186	1.744137	5.233849e-08
0.484429	1.743749	5.078366e-08
0.486682	1.743365	4.922161e-08
0.488946	1.742986	4.765228e-08
0.49122	1.74261	4.607566e-08
0.493505	1.742239	4.449170e-08
0.4958	1.741871	4.290038e-08
0.498107	1.741508	4.130165e-08
0.5	1.741214	3.998900e-08
0.500423	1.741149	3.987343e-08
0.502751	1.740793	3.923803e-08
0.505089	1.740441	3.859967e-08
0.507439	1.740094	3.795835e-08
0.509799	1.739749	3.731405e-08
0.51217	1.739409	3.666675e-08
0.514553	1.739072	3.601643e-08
0.516946	1.738738	3.536309e-08
0.51935	1.738408	3.470672e-08
0.521766	1.738082	3.404729e-08
0.524193	1.737759	3.338479e-08
0.526631	1.737439	3.271921e-08
0.529081	1.737122	3.205054e-08
0.531542	1.736809	3.137875e-08
0.534014	1.736499	3.070384e-08
0.536498	1.736193	3.002580e-08
0.538993	1.735889	2.934459e-08
0.5415	1.735589	2.866022e-08
0.544019	1.735291	2.797267e-08
0.546549	1.734997	2.728192e-08
0.549092	1.734706	2.658795e-08
0.55	1.734603	2.634000e-08
0.551646	1.734417	2.626078e-08
0.554212	1.734132	2.613725e-08
0.556789	1.733849	2.601316e-08
0.559379	1.733569	2.588848e-08
0.561981	1.733292	2.576323e-08
0.564595	1.733018	2.563740e-08
0.567221	1.732747	2.551097e-08
0.569859	1.732478	2.538396e-08
0.57251	1.732211	2.525636e-08
0.575173	1.731948	2.512817e-08
0.577848	1.731687	2.499938e-08
0.580536	1.731428	2.486999e-08
0.583236	1.731172	2.474000e-08
0.585949	1.730919	2.460941e-08
0.588675	1.730668	2.447820e-08
0.591413	1.730419	2.434639e-08
0.594164	1.730173	2.421396e-08
0.596927	1.729929	2.408092e-08
0.599704	1.729688	2.394726e-08
0.6	1.729662	2.393300e-08
0.602493	1.729449	2.377339e-08
0.605296	1.729212	2.359398e-08
0.608111	1.728977	2.341373e-08
0.61094	1.728744	2.323265e-08
0.613781	1.728514	2.305073e-08
0.616636	1.728286	2.286796e-08
0.619504	1.72806	2.268434e-08
0.622386	1.727836	2.249986e-08
0.625281	1.727614	2.231453e-08
0.628189	1.727394	2.212833e-08
0.631111	1.727176	2.194127e-08
0.634047	1.726961	2.175334e-08
0.636996	1.726747	2.156454e-08
0.639959	1.726535	2.137485e-08
0.642935	1.726325	2.118429e-08
0.645926	1.726117	2.099283e-08
0.64893	1.72591	2.080049e-08
0.65	1.725838	2.073200e-08
0.651949	1.725706	2.035866e-08
0.654981	1.725503	1.977765e-08
0.658028	1.725303	1.919393e-08
0.661088	1.725104	1.860750e-08
0.664163	1.724906	1.801834e-08
0.667252	1.724711	1.742644e-08
0.670356	1.724517	1.683179e-08
0.673474	1.724325	1.623437e-08
0.676607	1.724134	1.563418e-08
0.679754	1.723945	1.503119e-08
0.682915	1.723758	1.442539e-08
0.686092	1.723573	1.381678e-08
0.689283	1.723389	1.320534e-08
0.692489	1.723206	1.259106e-08
0.69571	1.723025	1.197391e-08
0.698946	1.722846	1.135390e-08
0.7	1.722788	1.115200e-08
0.702197	1.722668	1.118700e-08
0.705463	1.722491	1.123903e-08
0.708745	1.722316	1.129130e-08
0.712041	1.722143	1.134382e-08
0.715353	1.72197	1.139658e-08
0.718681	1.7218	1.144958e-08
0.722023	1.72163	1.150283e-08
0.725382	1.721462	1.155633e-08
0.728756	1.721295	1.161008e-08
0.732146	1.72113	1.166408e-08
0.735551	1.720966	1.171833e-08
0.738972	1.720803	1.177283e-08
0.742409	1.720642	1.182758e-08
0.745863	1.720482	1.188259e-08
0.749332	1.720323	1.193786e-08
0.752817	1.720165	1.199338e-08
0.756319	1.720008	1.204916e-08
0.759837	1.719853	1.210520e-08
0.763371	1.719699	1.216150e-08
0.766922	1.719546	1.221806e-08
0.770489	1.719394	1.227489e-08
0.774073	1.719243	1.233198e-08
0.777673	1.719093	1.238933e-08
0.78129	1.718945	1.244696e-08
0.784924	1.718797	1.250485e-08
0.788575	1.718651	1.256301e-08
0.792243	1.718505	1.262144e-08
0.795928	1.718361	1.268014e-08
0.79963	1.718217	1.273911e-08
0.8	1.718203	1.274500e-08
0.80335	1.718075	1.279840e-08
0.807086	1.717934	1.285796e-08
0.81084	1.717793	1.291780e-08
0.814612	1.717654	1.297791e-08
0.818401	1.717515	1.303831e-08
0.822208	1.717378	1.309899e-08
0.826032	1.717241	1.315995e-08
0.829874	1.717105	1.322119e-08
0.833734	1.71697	1.328272e-08
0.837612	1.716836	1.334454e-08
0.841508	1.716703	1.340664e-08
0.845422	1.716571	1.346903e-08
0.849355	1.716439	1.353171e-08
0.85	1.716418	1.354200e-08
0.853305	1.716308	1.359462e-08
0.857274	1.716179	1.365781e-08
0.861262	1.71605	1.372129e-08
0.865268	1.715921	1.378506e-08
0.869292	1.715794	1.384913e-08
0.873336	1.715667	1.391350e-08
0.877398	1.715541	1.397817e-08
0.881479	1.715416	1.404315e-08
0.885579	1.715291	1.410842e-08
0.889698	1.715167	1.417399e-08
0.893836	1.715044	1.423988e-08
0.897994	1.714921	1.430606e-08
0.9	1.714863	1.433800e-08
0.902171	1.7148	1.437260e-08
0.906367	1.714678	1.443949e-08
0.910583	1.714558	1.450669e-08
0.914818	1.714438	1.457420e-08
0.919073	1.714319	1.464203e-08
0.923348	1.7142	1.471017e-08
0.927643	1.714082	1.477863e-08
0.931958	1.713964	1.484741e-08
0.936293	1.713848	1.491651e-08
0.940648	1.713731	1.498593e-08
0.945023	1.713615	1.505567e-08
0.949419	1.7135	1.512573e-08
0.95	1.713485	1.513500e-08
0.953835	1.713385	1.519605e-08
0.958271	1.713271	1.526668e-08
0.962729	1.713157	1.533764e-08
0.967207	1.713044	1.540893e-08
0.971705	1.712931	1.548055e-08
0.976225	1.712819	1.555250e-08
0.980766	1.712707	1.562479e-08
0.985328	1.712596	1.569742e-08
0.989911	1.712485	1.577038e-08
0.994515	1.712375	1.584368e-08
0.999141	1.712265	1.591732e-08
1	1.712244	1.593100e-08
1.00379	1.712155	1.599136e-08
1.00846	1.712046	1.606575e-08
1.01315	1.711937	1.614049e-08
1.01786	1.711828	1.621558e-08
1.02259	1.71172	1.629101e-08
1.02735	1.711612	1.636680e-08
1.03213	1.711505	1.644293e-08
1.03693	1.711398	1.651943e-08
1.04175	1.711291	1.659628e-08
1.0466	1.711185	1.667348e-08
1.05147	1.711079	1.675105e-08
1.05636	1.710973	1.682897e-08
1.06	1.710894	1.688700e-08
1.06127	1.710867	1.690726e-08
1.06621	1.710762	1.698593e-08
1.07117	1.710657	1.706496e-08
1.07615	1.710552	1.714435e-08
1.08115	1.710448	1.722412e-08
1.08618	1.710343	1.730426e-08
1.09124	1.710239	1.738477e-08
1.09631	1.710135	1.746565e-08
1.10141	1.710032	1.754691e-08
1.10653	1.709928	1.762855e-08
1.11168	1.709825	1.771057e-08
1.11685	1.709722	1.779297e-08
1.12205	1.709619	1.787576e-08
1.12727	1.709517	1.795892e-08
1.13251	1.709414	1.804248e-08
1.13778	1.709312	1.812642e-08
1.14307	1.709209	1.821076e-08
1.14839	1.709107	1.829549e-08
1.15373	1.709005	1.838061e-08
1.15909	1.708903	1.846612e-08
1.16448	1.708801	1.855204e-08
1.1699	1.708699	1.863835e-08
1.17534	1.708598	1.872507e-08
1.18081	1.708496	1.881219e-08
1.1863	1.708394	1.889971e-08
1.19182	1.708293	1.898764e-08
1.19736	1.708191	1.907598e-08
1.2	1.708143	1.911800e-08
1.20293	1.70809	1.916472e-08
1.20853	1.707988	1.925385e-08
1.21415	1.707887	1.934340e-08
1.2198	1.707785	1.943336e-08
1.22547	1.707684	1.952374e-08
1.23117	1.707582	1.961454e-08
1.2369	1.70748	1.970577e-08
1.24265	1.707379	1.979742e-08
1.24843	1.707277	1.988949e-08
1.25424	1.707175	1.998199e-08
1.26007	1.707074	2.007493e-08
1.26593	1.706972	2.016829e-08
1.27182	1.70687	2.026209e-08
1.27774	1.706768	2.035633e-08
1.28368	1.706665	2.045101e-08
1.28965	1.706563	2.054612e-08
1.29565	1.706461	2.064168e-08
1.30167	1.706358	2.073768e-08
1.30773	1.706255	2.083413e-08
1.31381	1.706153	2.093103e-08
1.31992	1.706049	2.102837e-08
1.32606	1.705946	2.112617e-08
1.33223	1.705843	2.122443e-08
1.33843	1.705739	2.132314e-08
1.34465	1.705635	2.142231e-08
1.35091	1.705531	2.152195e-08
1.35719	1.705427	2.162204e-08
1.3635	1.705323	2.172260e-08
1.36985	1.705218	2.182363e-08
1.37622	1.705113	2.192513e-08
1.38262	1.705008	2.202711e-08
1.38905	1.704902	2.212955e-08
1.39551	1.704796	2.223247e-08
1.4	1.704723	2.230400e-08
1.402	1.70469	2.233588e-08
1.40852	1.704584	2.243976e-08
1.41507	1.704477	2.254412e-08
1.42166	1.70437	2.264897e-08
1.42827	1.704263	2.275431e-08
1.43491	1.704155	2.286014e-08
1.44159	1.704047	2.296646e-08
1.44829	1.703938	2.307328e-08
1.45503	1.703829	2.318059e-08
1.4618	1.70372	2.328840e-08
1.46859	1.703611	2.339671e-08
1.47543	1.703501	2.350553e-08
1.48229	1.70339	2.361485e-08
1.48918	1.703279	2.372468e-08
1.49611	1.703168	2.383503e-08
1.50307	1.703056	2.394588e-08
1.51006	1.702944	2.405725e-08
1.51708	1.702831	2.416914e-08
1.52414	1.702718	2.428155e-08
1.53123	1.702604	2.439448e-08
1.53835	1.70249	2.450794e-08
1.54551	1.702376	2.462193e-08
1.5527	1.70226	2.473644e-08
1.55992	1.702145	2.485149e-08
1.56717	1.702028	2.496707e-08
1.57446	1.701911	2.508319e-08
1.58179	1.701794	2.519985e-08
1.58914	1.701676	2.531706e-08
1.59654	1.701557	2.543481e-08
1.6	1.701502	2.549000e-08
1.60396	1.701438	2.669249e-08
1.61142	1.701318	2.895725e-08
1.61892	1.701198	3.123255e-08
1.62645	1.701077	3.351843e-08
1.63401	1.700955	3.581494e-08
1.64161	1.700832	3.812214e-08
1.64925	1.700709	4.044006e-08
1.65692	1.700586	4.276877e-08
1.66463	1.700461	4.510831e-08
1.67237	1.700336	4.745873e-08
1.68015	1.70021	4.982008e-08
1.68796	1.700083	5.219242e-08
1.69581	1.699956	5.457579e-08
1.7037	1.699828	5.697025e-08
1.71163	1.699699	5.937584e-08
1.71959	1.699569	6.179263e-08
1.72759	1.699438	6.422065e-08
1.73562	1.699307	6.665997e-08
1.74369	1.699175	6.911064e-08
1.75181	1.699042	7.157270e-08
1.75995	1.698908	7.404622e-08
1.76814	1.698773	7.653124e-08
1.77636	1.698638	7.902782e-08
1.78463	1.698501	8.153601e-08
1.79293	1.698364	8.405587e-08
1.8	1.698246	8.620300e-08
1.80127	1.698225	8.789906e-08
1.80964	1.698086	9.911955e-08
1.81806	1.697946	1.103922e-07
1.82652	1.697805	1.217173e-07
1.83501	1.697662	1.330951e-07
1.84355	1.697519	1.445259e-07
1.85212	1.697375	1.560097e-07
1.86074	1.69723	1.675470e-07
1.86939	1.697084	1.791380e-07
1.87809	1.696936	1.907829e-07
1.88682	1.696788	2.024819e-07
1.8956	1.696639	2.142354e-07
1.90442	1.696488	2.260435e-07
1.91328	1.696336	2.379065e-07
1.92218	1.696184	2.498248e-07
1.93112	1.69603	2.617984e-07
1.9401	1.695875	2.738278e-07
1.94912	1.695718	2.859131e-07
1.95819	1.695561	2.980546e-07
1.9673	1.695402	3.102526e-07
1.97645	1.695242	3.225073e-07
1.98564	1.695081	3.348191e-07
1.99488	1.694919	3.471881e-07
2	1.694828	3.540500e-07
2.00416	1.694755	3.676547e-07
2.01348	1.69459	3.981772e-07
2.02284	1.694424	4.288417e-07
2.03225	1.694256	4.596488e-07
2.0417	1.694087	4.905993e-07
2.0512	1.693917	5.216936e-07
2.06074	1.693745	5.529326e-07
2.07033	1.693572	5.843169e-07
2.07996	1.693398	6.158472e-07
2.08963	1.693222	6.475242e-07
2.09935	1.693044	6.793484e-07
2.10912	1.692865	7.113207e-07
2.11893	1.692685	7.434418e-07
2.12878	1.692503	7.757122e-07
2.13868	1.69232	8.081327e-07
2.14863	1.692135	8.407040e-07
2.15862	1.691948	8.734269e-07
2.16867	1.69176	9.063019e-07
2.17875	1.69157	9.393298e-07
2.18889	1.691379	9.725114e-07
2.19907	1.691186	1.005847e-06
2.2	1.691168	1.008900e-06
2.2093	1.690991	1.147972e-06
2.21957	1.690794	1.301703e-06
2.2299	1.690596	1.456150e-06
2.24027	1.690396	1.611315e-06
2.25069	1.690194	1.767201e-06
2.26116	1.689991	1.923813e-06
2.27167	1.689786	2.081153e-06
2.28224	1.689579	2.239225e-06
2.29286	1.68937	2.398033e-06
2.30352	1.689159	2.557578e-06
2.31424	1.688946	2.717866e-06
2.325	1.688731	2.878900e-06

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: —

D-LAF79 (CDGM): all datasets

LAF (Lanthanum flint)

D-LAF79 n,k 0.365–2.325 µm default

About D-LAF79 (CDGM)

CDGM Glass Co., Ltd. is a leading manufacturer of optical glass based in China. The company offers a wide range of optical materials, including various types of crown and flint glasses, which are used in applications ranging from consumer electronics to advanced scientific instruments. Known for their capacity for large-scale production as well as their commitment to quality, CDGM has positioned itself as a major player in both domestic and international markets. Their optical glass products are often used in lenses, prisms, and other optical components that require high precision and reliability. With an extensive catalog that caters to different optical requirements, such as high refractive indices or low dispersion, CDGM serves a diverse clientele including manufacturers of microscopes, telescopes, cameras, and other high-precision optical equipment. The company's expertise in glass science and its ability to provide customized solutions have made it a go-to supplier for businesses seeking high-quality, reliable optical glass.

More about D-LAF79 (CDGM) →

Provenance

Version: 1 (snapshot c5c2f18)
Source page: refractiveindex.info
Original file: database/data/specs/cdgm/optical/D-LAF79.yml
ID: ds_e2799131aea8
API: /v1/datasets/ds_e2799131aea8

Plot