Optical constants

Refractive index of N-LAK12 (SCHOTT)

N-LAK12: n,k 0.32–2.5 µm

Data
formula 2 + tabulated k
Range
0.32–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.32–2.5 µm
Refractive index n
1.6779
Extinction coefficient k
1.95563e-08
Permittivity ε1
2.81534
Permittivity ε2
6.56269e-08
Absorption coefficient α
0.0041823 cm⁻¹
Penetration depth δ = λ/(2πk)
4.78206e+09 nm
Abbe number Vd
55.2
Chromatic dispersion dn/dλ
-0.0632677 µm⁻¹
Group index ng
1.71507
Group velocity dispersion
113.069 fs²/mm
Dispersion parameter D
-616.852 ps/(nm·km)
Photon energy
2.11001 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

# N-LAK12 (SCHOTT): N-LAK12
schott_n_lak12 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-LAK12", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_lak12.range_nm)  # (320, 2500) nm
eps = schott_n_lak12.eps([633])  # 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=1.17365704λ2λ2−0.00577031797+0.588992398λ2λ2−0.0200401678+0.978014394λ2λ2−95.4873482

Valid from 0.32 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.17365704
C30.00577031797
C40.588992398
C50.0200401678
C60.978014394
C795.4873482

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: -5.67e-06 8.27e-09 1.27e-12 5.25e-07 6.3e-10 0.162
nd
1.6779
Vd
55.2
glass code
678552.410
glass status
standard
density
value: 4100
thermal expansion
value: 7.6e-06, temperature range: 243 343; value: 9.3e-06, temperature range: 293 573
dPgF
-0.0024
resistance
acid: 53.3; stain: 1.0; alkali: 3.3; climatic: 3.0; phosphate: 4.3

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = -2.30e-06 K⁻¹ at 633 nm, dn/dT = -2.83e-06 K⁻¹ at 1310 nm, dn/dT = -2.87e-06 K⁻¹ at 1550 nm

References

Cite

SCHOTT Zemax catalog 2017-01-20b (obtained from http://www.schott.com); See also SCHOTT 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 421 wavelengths, the same grid as the API and the library
N-LAK12 (SCHOTT), N-LAK12: n and k versus wavelength
λ (µm)nk
0.321.7248194.690800e-06
0.3216531.7240674.375097e-06
0.3233141.7233254.057764e-06
0.3249851.7225933.738791e-06
0.3266631.7218713.418170e-06
0.3283511.7211593.095894e-06
0.3300471.7204562.771952e-06
0.3317521.7197622.446338e-06
0.3334651.7190782.119041e-06
0.3341.7188672.016900e-06
0.3351881.7184021.931400e-06
0.3369191.7177361.806763e-06
0.3386591.7170781.681482e-06
0.3404091.7164291.555553e-06
0.3421671.7157881.428974e-06
0.3439351.7151561.301741e-06
0.3457111.7145321.173851e-06
0.3474971.7139161.045300e-06
0.3492921.7133089.160855e-07
0.351.7130718.651200e-07
0.3510961.7127078.286155e-07
0.352911.7121157.682256e-07
0.3547331.711537.075238e-07
0.3565651.7109526.465083e-07
0.3584071.7103825.851778e-07
0.3602581.7098195.235304e-07
0.3621191.7092634.615645e-07
0.363991.7087143.992786e-07
0.3651.7084213.656400e-07
0.365871.7081723.503249e-07
0.367761.7076373.170552e-07
0.369661.7071082.836136e-07
0.371.7070142.776200e-07
0.3715691.7065862.604912e-07
0.3734881.706072.395378e-07
0.3754181.7055612.184762e-07
0.3773571.7050581.973058e-07
0.3793061.7045621.760260e-07
0.381.7043871.684500e-07
0.3812651.7040711.602329e-07
0.3832351.7035861.474435e-07
0.3852141.7031081.345880e-07
0.3872041.7026351.216661e-07
0.3892041.7021681.086774e-07
0.391.7019841.035100e-07
0.3912151.7017071.005063e-07
0.3932361.7012519.550921e-08
0.3952671.70089.048633e-08
0.3973091.7003558.543750e-08
0.3993611.6999168.036259e-08
0.41.6997817.878200e-08
0.4014241.6994827.789275e-08
0.4034971.6990527.659762e-08
0.4051.6987467.565900e-08
0.4055821.6986287.527536e-08
0.4076771.698217.389320e-08
0.4097821.6977967.250390e-08
0.4118991.6973867.110742e-08
0.4140271.6969826.970374e-08
0.4161651.6965836.829280e-08
0.4183151.6961886.687457e-08
0.421.6958836.576300e-08
0.4204761.6957986.557813e-08
0.4226481.6954126.473446e-08
0.4248311.6950316.388643e-08
0.4270261.6946546.303402e-08
0.4292311.6942826.217721e-08
0.4314491.6939146.131597e-08
0.4336771.693556.045028e-08
0.4359171.693195.958012e-08
0.4361.6931775.954800e-08
0.4381691.6928355.847008e-08
0.4404321.6924845.734528e-08
0.4427071.6921365.621468e-08
0.4449941.6917935.507824e-08
0.4472931.6914535.393592e-08
0.4496031.6911185.278771e-08
0.4519261.6907865.163356e-08
0.454261.6904585.047345e-08
0.4566071.6901344.930735e-08
0.4589651.6898134.813523e-08
0.461.6896744.762100e-08
0.4613361.6894964.677990e-08
0.4637191.6891824.527967e-08
0.4661141.6888724.377168e-08
0.4685221.6885664.225591e-08
0.4709421.6882634.073231e-08
0.4733751.6879633.920083e-08
0.475821.6876663.766145e-08
0.4782781.6873733.611412e-08
0.4807481.6870833.455879e-08
0.4832321.6867963.299543e-08
0.4857281.6865133.142399e-08
0.4882371.6862322.984443e-08
0.4907591.6859552.825672e-08
0.4932941.685682.666080e-08
0.4958421.6854092.505665e-08
0.4984031.685142.344420e-08
0.51.6849752.243900e-08
0.5009781.6848742.229603e-08
0.5035661.6846122.191765e-08
0.5061671.6843522.153731e-08
0.5087811.6840952.115501e-08
0.5114091.683842.077074e-08
0.5140511.6835882.038448e-08
0.5167061.6833391.999622e-08
0.5193761.6830931.960596e-08
0.5220581.6828491.921369e-08
0.5247551.6826081.881939e-08
0.5274661.6823691.842305e-08
0.530191.6821331.802466e-08
0.5329291.68191.762422e-08
0.5356821.6816681.722170e-08
0.5384491.681441.681711e-08
0.541231.6812131.641043e-08
0.5440261.6809891.600165e-08
0.5461.6808331.571300e-08
0.5468361.6807671.578289e-08
0.5496611.6805481.601900e-08
0.55251.6803311.625632e-08
0.5553541.6801151.649488e-08
0.5582231.6799031.673467e-08
0.5611061.6796921.697569e-08
0.5640041.6794831.721796e-08
0.5669181.6792771.746149e-08
0.5698461.6790731.770627e-08
0.572791.678871.795231e-08
0.5757491.678671.819963e-08
0.5787231.6784721.844822e-08
0.581.6783881.855500e-08
0.5817121.6782761.878055e-08
0.5847171.6780811.917643e-08
0.5877371.6778891.957437e-08
0.5907731.6776981.997435e-08
0.5938251.677512.037640e-08
0.5968921.6773232.078053e-08
0.5999751.6771382.118675e-08
0.6030741.6769552.159507e-08
0.606191.6767732.200549e-08
0.6093211.6765942.241803e-08
0.6124681.6764162.283271e-08
0.6156321.676242.324953e-08
0.6188121.6760652.366850e-08
0.621.6760012.382500e-08
0.6220091.6758922.379547e-08
0.6252221.6757212.374824e-08
0.6284511.6755512.370077e-08
0.6316971.6753832.365305e-08
0.634961.6752172.360508e-08
0.638241.6750522.355687e-08
0.6415371.6748892.350840e-08
0.6448511.6747272.345969e-08
0.6481821.6745662.341073e-08
0.651531.6744072.336151e-08
0.6548961.674252.331203e-08
0.6582781.6740942.326231e-08
0.661.6740152.323700e-08
0.6616791.6739392.291866e-08
0.6650971.6737862.227054e-08
0.6685321.6736342.161908e-08
0.6719861.6734842.096425e-08
0.6754571.6733342.030603e-08
0.6789461.6731861.964442e-08
0.6824531.673041.897939e-08
0.6859781.6728941.831092e-08
0.6895211.672751.763900e-08
0.6930831.6726081.696361e-08
0.6966631.6724661.628473e-08
0.71.6723361.565200e-08
0.7002621.6723261.566033e-08
0.7038791.6721861.577536e-08
0.7075151.6720481.589100e-08
0.711171.6719111.600722e-08
0.7148431.6717761.612405e-08
0.7185361.6716411.624148e-08
0.7222471.6715071.635952e-08
0.7259781.6713751.647817e-08
0.7297281.6712441.659743e-08
0.7334971.6711131.671731e-08
0.7372861.6709841.683781e-08
0.7410951.6708561.695893e-08
0.7449231.6707281.708067e-08
0.7487711.6706021.720304e-08
0.7526391.6704771.732605e-08
0.7565261.6703521.744969e-08
0.7604341.6702291.757397e-08
0.7643621.6701071.769889e-08
0.768311.6699851.782446e-08
0.7722791.6698641.795068e-08
0.7762681.6697451.807754e-08
0.7802781.6696261.820507e-08
0.7843091.6695081.833325e-08
0.788361.6693911.846209e-08
0.7924321.6692741.859160e-08
0.7965261.6691591.872178e-08
0.800641.6690441.885263e-08
0.8047761.668931.898416e-08
0.8089331.6688171.911636e-08
0.8131111.6687051.924925e-08
0.8173111.6685931.938283e-08
0.8215331.6684821.951709e-08
0.8257771.6683721.965205e-08
0.8300421.6682621.978771e-08
0.834331.6681541.992406e-08
0.838641.6680462.006113e-08
0.8429721.6679382.019889e-08
0.8473261.6678312.033738e-08
0.8517031.6677252.047657e-08
0.8561021.667622.061649e-08
0.8605241.6675152.075712e-08
0.864971.6674112.089849e-08
0.8694371.6673072.104058e-08
0.8739291.6672042.118341e-08
0.8784431.6671022.132698e-08
0.882981.6672.147129e-08
0.8875411.6668982.161634e-08
0.8921261.6667982.176214e-08
0.8967341.6666972.190870e-08
0.9013661.6665982.205601e-08
0.9060221.6664982.220408e-08
0.9107021.6663992.235292e-08
0.9154071.6663012.250253e-08
0.9201351.6662032.265291e-08
0.9248881.6661062.280407e-08
0.9296661.6660092.295600e-08
0.9344681.6659132.310873e-08
0.9392951.6658172.326224e-08
0.9441471.6657212.341654e-08
0.9490241.6656262.357164e-08
0.9539261.6655312.372755e-08
0.9588531.6654362.388425e-08
0.9638061.6653422.404177e-08
0.9687851.6652482.420010e-08
0.9737891.6651552.435925e-08
0.9788191.6650622.451922e-08
0.9838751.6649692.468002e-08
0.9889571.6648772.484165e-08
0.9940661.6647852.500411e-08
0.9992011.6646932.516741e-08
1.004361.6646012.533156e-08
1.009551.664512.549655e-08
1.014761.6644192.566240e-08
1.020011.6643282.582910e-08
1.025281.6642382.599666e-08
1.030571.6641482.616509e-08
1.035891.6640582.633439e-08
1.041251.6639682.650457e-08
1.046621.6638782.667562e-08
1.052031.6637892.684755e-08
1.057461.66372.702038e-08
1.061.6636582.710100e-08
1.062931.663612.770015e-08
1.068421.6635222.882395e-08
1.073941.6634332.995355e-08
1.079481.6633443.108899e-08
1.085061.6632563.223029e-08
1.090671.6631673.337749e-08
1.09631.6630793.453061e-08
1.101961.6629913.568969e-08
1.107651.6629033.685475e-08
1.113381.6628153.802584e-08
1.119131.6627273.920297e-08
1.124911.6626394.038619e-08
1.130721.6625514.157551e-08
1.136561.6624644.277098e-08
1.142431.6623764.397263e-08
1.148331.6622884.518048e-08
1.154261.66224.639457e-08
1.160231.6621134.761493e-08
1.166221.6620254.884160e-08
1.172241.6619375.007460e-08
1.17831.6618495.131397e-08
1.184381.6617625.255974e-08
1.19051.6616745.381195e-08
1.196651.6615865.507063e-08
1.202831.6614985.633581e-08
1.209051.661415.760752e-08
1.215291.6613225.888580e-08
1.221571.6612336.017069e-08
1.227881.6611456.146221e-08
1.234221.6610576.276040e-08
1.24061.6609686.406530e-08
1.2471.6608796.537694e-08
1.253451.660796.669536e-08
1.259921.6607016.802059e-08
1.266431.6606126.935266e-08
1.272971.6605237.069161e-08
1.279551.6604337.203748e-08
1.286161.6603437.339030e-08
1.29281.6602537.475011e-08
1.299481.6601637.611694e-08
1.306191.6600727.749083e-08
1.312941.6599827.887182e-08
1.319721.6598918.025994e-08
1.326541.6597998.165524e-08
1.333391.6597088.305774e-08
1.340281.6596168.446748e-08
1.34721.6595248.588451e-08
1.354161.6594318.730886e-08
1.361151.6593398.874056e-08
1.368181.6592469.017966e-08
1.375251.6591529.162620e-08
1.382351.6590589.308020e-08
1.38951.6589649.454172e-08
1.396671.658879.601078e-08
1.403891.6587759.748744e-08
1.411141.658689.897172e-08
1.418431.6585841.004637e-07
1.425761.6584881.019633e-07
1.433121.6583911.034707e-07
1.440521.6582941.049859e-07
1.447961.6581971.065089e-07
1.455441.6580991.080398e-07
1.462961.6581.095786e-07
1.470521.6579021.111253e-07
1.478111.6578021.126801e-07
1.485751.6577021.142428e-07
1.493421.6576021.158137e-07
1.501141.6575011.173926e-07
1.508891.6573991.189797e-07
1.516691.6572971.205750e-07
1.524521.6571951.221785e-07
1.531.6571231.233000e-07
1.53241.6570921.281776e-07
1.540311.6569881.442930e-07
1.548271.6568831.604917e-07
1.556271.6567781.767740e-07
1.56431.6566731.931404e-07
1.572381.6565662.095913e-07
1.580511.6564592.261272e-07
1.588671.6563522.427486e-07
1.596881.6562432.594558e-07
1.605131.6561342.762493e-07
1.613421.6560252.931295e-07
1.621751.6559143.100970e-07
1.630131.6558033.271521e-07
1.638551.6556913.442953e-07
1.647011.6555783.615270e-07
1.655521.6554653.788478e-07
1.664071.655353.962580e-07
1.672671.6552354.137581e-07
1.681311.6551194.313487e-07
1.689991.6550024.490301e-07
1.698721.6548854.668028e-07
1.70751.6547664.846674e-07
1.716321.6546475.026242e-07
1.725181.6545265.206738e-07
1.734091.6544055.388166e-07
1.743051.6542835.570532e-07
1.752061.654165.753839e-07
1.761111.6540365.938093e-07
1.77021.6539116.123299e-07
1.779351.6537856.309462e-07
1.788541.6536586.496586e-07
1.797781.653536.684677e-07
1.807061.6534016.873740e-07
1.81641.653277.063779e-07
1.825781.6531397.254799e-07
1.835211.6530077.446807e-07
1.844691.6528737.639806e-07
1.854221.6527397.833802e-07
1.86381.6526038.028801e-07
1.873421.6524668.224806e-07
1.88311.6523288.421824e-07
1.892831.6521898.619860e-07
1.902611.6520498.818919e-07
1.912431.6519079.019005e-07
1.922311.6517649.220126e-07
1.932241.651629.422285e-07
1.942221.6514749.625489e-07
1.952261.6513289.829742e-07
1.962341.6511791.003505e-06
1.971.6510671.019100e-06
1.972481.651031.046754e-06
1.982671.6508791.160527e-06
1.992911.6507271.274887e-06
2.00321.6505731.389839e-06
2.013551.6504181.505384e-06
2.023951.6502621.621526e-06
2.03441.6501041.738268e-06
2.044911.6499441.855613e-06
2.055481.6497831.973565e-06
2.066091.6496212.092125e-06
2.076771.6494572.211298e-06
2.087491.6492912.331087e-06
2.098281.6491242.451494e-06
2.109111.6489552.572523e-06
2.120011.6487842.694178e-06
2.130961.6486122.816460e-06
2.141971.6484382.939375e-06
2.153031.6482623.062924e-06
2.164151.6480853.187112e-06
2.175331.6479063.311941e-06
2.186571.6477253.437415e-06
2.197861.6475423.563537e-06
2.209221.6473573.690310e-06
2.220631.647173.817739e-06
2.23211.6469823.945825e-06
2.243631.6467924.074573e-06
2.255221.6465994.203987e-06
2.266871.6464054.334068e-06
2.278581.6462094.464822e-06
2.290351.646014.596251e-06
2.302181.645814.728359e-06
2.314071.6456074.861149e-06
2.3251.645424.983200e-06
2.326021.6454025.014982e-06
2.338041.6451955.388190e-06
2.350121.6449865.763326e-06
2.362251.6447756.140400e-06
2.374461.6445616.519421e-06
2.386721.6443466.900400e-06
2.399051.6441277.283347e-06
2.411441.6439077.668272e-06
2.42391.6436848.055186e-06
2.436421.6434598.444098e-06
2.449011.6432318.835019e-06
2.461661.6430019.227959e-06
2.474371.6427689.622929e-06
2.487151.6425321.001994e-05
2.51.6422941.041900e-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
—