Optical constants

Refractive index of IRG 24 (SCHOTT)

IRG 24: n,k 0.8–12 µm

Data
formula 2 + tabulated k
Range
0.8–12 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.8–12 µm
Refractive index n
2.62663
Extinction coefficient k
6.37712e-07
Permittivity ε1
6.89918
Permittivity ε2
3.35007e-06
Absorption coefficient α
0.0258507 cm⁻¹
Penetration depth δ = λ/(2πk)
7.73673e+08 nm
Abbe number Vd
—
Chromatic dispersion dn/dλ
-0.00691453 µm⁻¹
Group index ng
2.64806
Group velocity dispersion
319.654 fs²/mm
Dispersion parameter D
-62.6552 ps/(nm·km)
Photon energy
0.399949 eV

ε = (n + ik)², α = 4πk/λ, ng = 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

# IRG 24 (SCHOTT): IRG 24
schott_irg24 = ls.fetch_refractiveindex("specs", "SCHOTT-infrared", "IRG24", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_irg24.range_nm)  # (800, 12000) nm
eps = schott_irg24.eps([3100])  # complex permittivity

Downloads the original record once (pinned to the imported snapshot) and caches it.

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
n2−1=2.8965+2.9567λ2λ2−0.162+0.9461λ2λ2−1939.1

Valid from 0.8 to 12.0 µm.

Coefficients as stored
CiValue
C12.8965
C22.9567
C30.162
C40.9461
C51939.1

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 1.80e-05 0 0 2.10e-07 0 1.67e-03
density
value: 4410
thermal expansion
value: 20.0e-06, temperature range: 293 373
specific heat
value: 370
thermal conductivity
value: 0.18
transformation temperature
value: 498
hardness
type: Knoop, value: 1.12e9
fracture toughness
value: 0.347e6
shear modulus
value: 8.5e9
youngs modulus
value: 20.5e9

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = 2.09e-05 K⁻¹ at 1310 nm, dn/dT = 2.06e-05 K⁻¹ at 1550 nm

References

Cite

SCHOTT Infrared Chalcogenide Glasses - IRG 24 Product flyer (Version April 2017); Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 422 wavelengths, the same grid as the API and the library
IRG 24 (SCHOTT), IRG 24: n and k versus wavelength
λ (µm)nk
0.82.8026689.111900e-06
0.8054482.7994538.873213e-06
0.8109332.7963068.632901e-06
0.8164562.7932268.390952e-06
0.8220162.790218.147355e-06
0.8276142.7872577.902099e-06
0.833252.7843667.655173e-06
0.8389252.7815337.406566e-06
0.8446382.7787597.156265e-06
0.850392.7760416.904260e-06
0.8561822.7733786.650539e-06
0.8620122.7707696.395090e-06
0.8678832.7682126.137901e-06
0.8737932.7657055.878960e-06
0.8797442.7632495.618257e-06
0.8857352.760845.355777e-06
0.8917672.7584795.091511e-06
0.897842.7561634.825444e-06
0.9039552.7538934.557566e-06
0.9101112.7516664.287863e-06
0.9163092.7494824.016323e-06
0.9225492.747343.742935e-06
0.9288322.7452383.467684e-06
0.9351572.7431763.190559e-06
0.9415262.7411532.911547e-06
0.9479382.7391682.630634e-06
0.9543942.7372192.347809e-06
0.9608932.7353072.063057e-06
0.9674372.733431.776366e-06
0.9740252.7315881.487723e-06
0.9806592.7297791.197114e-06
0.9873372.7280039.045263e-07
0.9940612.726266.099457e-07
12.7247563.497600e-07
1.000832.7245483.496606e-07
1.007652.7228673.488456e-07
1.014512.7212163.480250e-07
1.021422.7195943.471988e-07
1.028372.7180023.463670e-07
1.035382.7164373.455296e-07
1.042432.71493.446864e-07
1.049532.713393.438375e-07
1.056682.7119073.429828e-07
1.063872.710453.421223e-07
1.071122.7090183.412559e-07
1.078412.707613.403836e-07
1.085762.7062273.395054e-07
1.093152.7048683.386212e-07
1.100592.7035323.377310e-07
1.108092.7022193.368347e-07
1.115642.7009293.359323e-07
1.123232.699663.350238e-07
1.130882.6984133.341091e-07
1.138582.6971863.331881e-07
1.146342.6959813.322609e-07
1.154142.6947953.313274e-07
1.1622.693633.303875e-07
1.169922.6924833.294412e-07
1.177892.6913563.284885e-07
1.185912.6902483.275292e-07
1.193982.6891583.265635e-07
1.202112.6880863.255912e-07
1.21032.6870313.246122e-07
1.218542.6859943.236266e-07
1.226842.6849733.226342e-07
1.23522.6839693.216352e-07
1.243612.6829823.206293e-07
1.252082.682013.196165e-07
1.26062.6810553.185969e-07
1.269192.6801143.175703e-07
1.277832.6791893.165367e-07
1.286542.6782783.154961e-07
1.29532.6773823.144484e-07
1.304122.6765013.133935e-07
1.3132.6756333.123315e-07
1.321942.6747793.112623e-07
1.330942.6739393.101857e-07
1.340012.6731123.091019e-07
1.349132.6722983.080106e-07
1.358322.6714973.069119e-07
1.367572.6707083.058058e-07
1.376892.6699323.046921e-07
1.386262.6691673.035708e-07
1.39572.6684153.024419e-07
1.405212.6676753.013053e-07
1.414782.6669453.001609e-07
1.424412.6662282.990088e-07
1.434112.6655212.978488e-07
1.443882.6648252.966809e-07
1.453712.664142.955051e-07
1.463612.6634652.943212e-07
1.473582.6628012.931293e-07
1.483622.6621462.919293e-07
1.493722.6615022.907211e-07
1.52.6611092.899700e-07
1.503892.6608682.902157e-07
1.514132.6602432.908624e-07
1.524442.6596282.915134e-07
1.534832.6590222.921690e-07
1.545282.6584252.928289e-07
1.55582.6578372.934934e-07
1.56642.6572582.941624e-07
1.577072.6566872.948359e-07
1.587812.6561262.955140e-07
1.598622.6555722.961968e-07
1.609512.6550272.968842e-07
1.620472.654492.975763e-07
1.63152.6539612.982731e-07
1.642612.653442.989746e-07
1.65382.6529262.996809e-07
1.665062.652423.003920e-07
1.67642.6519223.011080e-07
1.687822.6514313.018288e-07
1.699312.6509473.025546e-07
1.710892.650473.032853e-07
1.722542.6500013.040210e-07
1.734272.6495383.047616e-07
1.746082.6490823.055074e-07
1.757972.6486323.062582e-07
1.769942.6481893.070141e-07
1.781992.6477533.077752e-07
1.794132.6473233.085414e-07
1.806352.6468993.093129e-07
1.818652.6464813.100896e-07
1.831042.6460693.108716e-07
1.843512.6456633.116589e-07
1.856062.6452633.124516e-07
1.86872.6448693.132497e-07
1.881432.644483.140533e-07
1.894242.6440973.148623e-07
1.907142.6437193.156768e-07
1.920132.6433473.164968e-07
1.93322.642983.173225e-07
1.946372.6426193.181537e-07
1.959622.6422623.189907e-07
1.972972.641913.198333e-07
1.986412.6415643.206817e-07
1.999932.6412223.215358e-07
22.641223.215400e-07
2.013552.6408853.237189e-07
2.027272.6405533.259233e-07
2.041072.6402253.281428e-07
2.054972.6399033.303774e-07
2.068972.6395843.326272e-07
2.083062.639273.348923e-07
2.097242.6389613.371728e-07
2.111532.6386553.394689e-07
2.125912.6383543.417806e-07
2.140382.6380573.441080e-07
2.154962.6377643.464513e-07
2.169642.6374763.488106e-07
2.184412.6371913.511859e-07
2.199292.636913.535774e-07
2.214262.6366333.559852e-07
2.229342.636363.584094e-07
2.244532.636093.608501e-07
2.259812.6358243.633074e-07
2.27522.6355623.657815e-07
2.29072.6353033.682724e-07
2.30632.6350483.707802e-07
2.3222.6347963.733052e-07
2.337822.6345483.758473e-07
2.353742.6343033.784068e-07
2.369772.6340613.809836e-07
2.38592.6338233.835781e-07
2.402152.6335873.861902e-07
2.418512.6333553.888201e-07
2.434982.6331263.914679e-07
2.451572.63293.941337e-07
2.468262.6326773.968177e-07
2.485072.6324573.995199e-07
2.52.6322654.019200e-07
2.501992.6322394.032172e-07
2.519032.6320254.143008e-07
2.536192.6318134.254598e-07
2.553462.6316044.366948e-07
2.570852.6313984.480063e-07
2.588362.6311954.593949e-07
2.605982.6309944.708610e-07
2.623732.6307964.824052e-07
2.64162.63064.940281e-07
2.659592.6304075.057301e-07
2.67772.6302165.175117e-07
2.695942.6300285.293736e-07
2.71432.6298425.413163e-07
2.732782.6296585.533404e-07
2.751392.6294775.654463e-07
2.770132.6292985.776346e-07
2.7892.6291215.899060e-07
2.807992.6289466.022609e-07
2.827112.6287746.147000e-07
2.846372.6286046.272238e-07
2.865752.6284366.398328e-07
2.885272.6282696.525278e-07
2.904922.6281056.653092e-07
2.92472.6279436.781776e-07
2.944622.6277836.911337e-07
2.964672.6276257.041780e-07
2.984862.6274687.173111e-07
32.6273537.271600e-07
3.005192.6273147.225208e-07
3.025652.6271617.042145e-07
3.046262.6270116.857835e-07
3.0672.6268616.672270e-07
3.087892.6267146.485442e-07
3.108922.6265696.297341e-07
3.130092.6264256.107959e-07
3.151412.6262825.917287e-07
3.172872.6261425.725317e-07
3.194482.6260035.532040e-07
3.216232.6258655.337446e-07
3.238142.6257295.141527e-07
3.260192.6255954.944274e-07
3.282392.6254624.745677e-07
3.304742.625334.545728e-07
3.327252.62524.344417e-07
3.349912.6250724.141736e-07
3.372722.6249443.937674e-07
3.395692.6248193.732222e-07
3.418822.6246943.525371e-07
3.44212.6245713.317112e-07
3.465542.6244493.107434e-07
3.489142.6243282.896328e-07
3.52.6242732.799200e-07
3.51292.6242092.776398e-07
3.536832.624092.734120e-07
3.560912.6239732.691555e-07
3.585162.6238572.648699e-07
3.609582.6237432.605552e-07
3.634162.6236292.562111e-07
3.658912.6235172.518374e-07
3.683832.6234052.474339e-07
3.708922.6232952.430005e-07
3.734172.6231852.385368e-07
3.75962.6230772.340427e-07
3.785212.622972.295181e-07
3.810992.6228632.249626e-07
3.836942.6227582.203761e-07
3.863072.6226532.157584e-07
3.889382.622552.111092e-07
3.915872.6224472.064283e-07
3.942532.6223452.017156e-07
3.969382.6222441.969708e-07
3.996412.6221441.921937e-07
42.6221311.915600e-07
4.023632.6220452.149718e-07
4.051032.6219462.421197e-07
4.078622.6218492.694525e-07
4.10642.6217522.969714e-07
4.134362.6216553.246778e-07
4.162522.621563.525728e-07
4.190872.6214653.806578e-07
4.219412.6213714.089340e-07
4.248142.6212774.374028e-07
4.277072.6211844.660655e-07
4.30622.6210924.949234e-07
4.335522.6215.239778e-07
4.365052.6209095.532301e-07
4.394782.6208195.826816e-07
4.424712.6207296.123337e-07
4.454842.6206396.421877e-07
4.485182.6205516.722450e-07
4.52.6205086.869300e-07
4.515722.6204626.791684e-07
4.546482.6203746.639869e-07
4.577442.6202876.487021e-07
4.608612.62026.333131e-07
4.642.6201136.178194e-07
4.67162.6200276.022201e-07
4.703412.6199425.865146e-07
4.735442.6198565.707022e-07
4.767692.6197715.547820e-07
4.800162.6196875.387535e-07
4.832852.6196025.226157e-07
4.865762.6195185.063681e-07
4.89892.6194354.900099e-07
4.932262.6193514.735402e-07
4.965852.6192684.569584e-07
4.999672.6191854.402636e-07
52.6191844.401000e-07
5.033722.6191034.222515e-07
5.0682.619024.041047e-07
5.102512.6189383.858344e-07
5.137262.6188563.674397e-07
5.172252.6187743.489197e-07
5.207472.6186933.302735e-07
5.242932.6186113.115004e-07
5.278642.618532.925995e-07
5.314592.6184482.735698e-07
5.350782.6183672.544105e-07
5.387222.6182862.351207e-07
5.423912.6182052.156996e-07
5.460852.6181241.961462e-07
5.498042.6180431.764597e-07
5.52.6180391.754200e-07
5.535482.6179621.731515e-07
5.573182.6178811.707411e-07
5.611132.61781.683143e-07
5.649342.6177191.658710e-07
5.687822.6176381.634110e-07
5.726552.6175571.609343e-07
5.765552.6174761.584407e-07
5.804812.6173941.559302e-07
5.844352.6173131.534025e-07
5.884152.6172311.508576e-07
5.924222.617151.482954e-07
5.964562.6170681.457157e-07
62.6169961.434500e-07
6.005182.6169861.446510e-07
6.046082.6169031.541250e-07
6.087262.6168211.636636e-07
6.128712.6167381.732671e-07
6.170452.6166551.829361e-07
6.212472.6165721.926709e-07
6.254782.6164892.024719e-07
6.297372.6164052.123398e-07
6.340262.6163212.222748e-07
6.383442.6162372.322775e-07
6.426912.6161522.423483e-07
6.470682.6160672.524877e-07
6.52.616012.592800e-07
6.514752.6159812.549222e-07
6.559112.6158952.418110e-07
6.603782.6158092.286105e-07
6.648752.6157222.153201e-07
6.694032.6156352.019392e-07
6.739622.6155481.884671e-07
6.785522.615461.749034e-07
6.831732.6153711.612472e-07
6.878262.6152821.474980e-07
6.92512.6151921.336553e-07
6.972262.6151021.197182e-07
72.6150491.115200e-07
7.019742.6150111.165614e-07
7.067552.614921.287700e-07
7.115682.6148281.410618e-07
7.164142.6147351.534372e-07
7.212932.6146421.658970e-07
7.262052.6145481.784416e-07
7.31152.6144531.910716e-07
7.36132.6143582.037876e-07
7.411432.6142622.165903e-07
7.46192.6141652.294801e-07
7.52.6140922.392100e-07
7.512722.6140673.161796e-07
7.563882.6139696.258371e-07
7.615392.613879.376035e-07
7.667252.613771.251493e-06
7.719472.6136691.567520e-06
7.772042.6135671.885700e-06
7.824972.6134642.206046e-06
7.878262.6133612.528574e-06
7.931912.6132562.853298e-06
7.985932.613153.180234e-06
82.6131233.265400e-06
8.040312.6130443.040427e-06
8.095072.6129362.734862e-06
8.15022.6128282.427215e-06
8.20572.6127182.117473e-06
8.261592.6126081.805622e-06
8.317852.6124961.491647e-06
8.374492.6123831.175534e-06
8.431532.6122698.572679e-07
8.488952.6121535.368346e-07
8.52.6121314.751500e-07
8.546762.6120374.777638e-07
8.604962.6119194.810174e-07
8.663562.61184.842932e-07
8.722562.611684.875913e-07
8.781972.6115584.909119e-07
8.841772.6114354.942551e-07
8.901992.6113114.976211e-07
8.962612.6111855.010100e-07
92.6111075.031000e-07
9.023652.6110585.116309e-07
9.08512.6109295.337994e-07
9.146972.6107995.561188e-07
9.209262.6106685.785902e-07
9.271982.6105356.012146e-07
9.335132.61046.239931e-07
9.39872.6102646.469267e-07
9.462712.6101266.700166e-07
9.52.6100456.834700e-07
9.527152.6099867.028992e-07
9.592032.6098447.493324e-07
9.657352.6097017.960817e-07
9.723122.6095568.431495e-07
9.789342.609418.905378e-07
9.856012.6092619.382488e-07
9.923132.6091119.862847e-07
9.99072.6089581.034648e-06
102.6089371.041300e-06
10.05872.6088041.309474e-06
10.12722.6086481.622199e-06
10.19622.6084891.937053e-06
10.26572.6083292.254052e-06
10.33562.6081662.573209e-06
10.40592.6080022.894540e-06
10.47682.6078353.218059e-06
10.52.607783.323900e-06
10.54822.6076663.534428e-06
10.622.6074943.848418e-06
10.69232.6073214.164547e-06
10.76512.6071444.482828e-06
10.83852.6069664.803277e-06
10.91232.6067855.125908e-06
10.98662.6066025.450737e-06
112.6065685.509400e-06
11.06142.6064166.372015e-06
11.13672.6062277.430342e-06
11.21262.6060368.495877e-06
11.28892.6058429.568669e-06
11.36582.6056451.064877e-05
11.44322.6054451.173622e-05
11.52.6052981.253400e-05
11.52112.6052431.455268e-05
11.59962.6050382.204304e-05
11.67862.6048292.958442e-05
11.75812.6046183.717715e-05
11.83822.6044044.482159e-05
11.91882.6041865.251809e-05
122.6039656.026700e-05

Optical transmission calculator

Free-standing sample in vacuum, normal incidence
Method
Transmittance T
—
Reflectance R
—

Fresnel reflection calculator

Direction
Rp
—
Rs
—
R = (Rp+Rs)/2
—
Phase φp
—
Phase φs
—
Brewster angle θB
—
Critical angle θC
—