Optical constants

Refractive index of N-LAK8 (SCHOTT)

N-LAK8: n,k 0.31–2.5 µm

Data
formula 2 + tabulated k
Range
0.31–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.31–2.5 µm
Refractive index n
1.713
Extinction coefficient k
1.12565e-08
Permittivity ε1
2.93437
Permittivity ε2
3.85649e-08
Absorption coefficient α
0.00240732 cm⁻¹
Penetration depth δ = λ/(2πk)
8.30801e+09 nm
Abbe number Vd
53.832
Chromatic dispersion dn/dλ
-0.0683789 µm⁻¹
Group index ng
1.75318
Group velocity dispersion
119.636 fs²/mm
Dispersion parameter D
-652.676 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-LAK8 (SCHOTT): N-LAK8
schott_n_lak8 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-LAK8", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_lak8.range_nm)  # (310, 2500) nm
eps = schott_n_lak8.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=1.33183167λ2λ2−0.00620023871+0.546623206λ2λ2−0.0216465439+1.19084015λ2λ2−82.5827736

Valid from 0.31 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.33183167
C30.00620023871
C40.546623206
C50.0216465439
C61.19084015
C782.5827736

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 4.1e-06 1.25e-08 -1.6e-11 4.3e-07 6.29e-10 0.213
nd
1.713
Vd
53.83
glass code
713538.375
glass status
standard
density
value: 3749
thermal expansion
value: 5.6e-06, temperature range: 243 343; value: 6.7e-06, temperature range: 293 573
dPgF
-0.0083
resistance
acid: 52.3; stain: 2.0; alkali: 1.0; climatic: 3.0; phosphate: 3.3

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = 2.99e-06 K⁻¹ at 633 nm, dn/dT = 2.40e-06 K⁻¹ at 1310 nm, dn/dT = 2.35e-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 422 wavelengths, the same grid as the API and the library
N-LAK8 (SCHOTT), N-LAK8: n and k versus wavelength
λ (µm)nk
0.311.7685724.544200e-06
0.3116261.7676774.338417e-06
0.3132611.7667954.131555e-06
0.3149041.7659253.923608e-06
0.3165561.7650683.714571e-06
0.3182161.7642233.504436e-06
0.3198851.7633893.293200e-06
0.321.7633333.278700e-06
0.3215631.7625673.112904e-06
0.323251.7617572.934024e-06
0.3249461.7609582.754206e-06
0.326651.760172.573444e-06
0.3283641.7593932.391734e-06
0.3300861.7586262.209071e-06
0.3318181.757872.025450e-06
0.3335581.7571241.840866e-06
0.3341.7569371.794000e-06
0.3353081.7563881.716120e-06
0.3370671.7556631.611377e-06
0.3388351.7549471.506083e-06
0.3406121.754241.400238e-06
0.3423991.7535431.293837e-06
0.3441951.7528561.186878e-06
0.3461.7521771.079358e-06
0.3478151.7515089.712746e-07
0.349641.7508478.626237e-07
0.351.7507188.411600e-07
0.3514741.7501957.960194e-07
0.3533171.7495517.395437e-07
0.3551711.7489166.827716e-07
0.3570341.7482896.257018e-07
0.3589061.7476715.683327e-07
0.3607891.747065.106626e-07
0.3626821.7464574.526900e-07
0.3645841.7458623.944133e-07
0.3651.7457343.816700e-07
0.3664961.7452753.550189e-07
0.3684191.7446953.207801e-07
0.371.7442262.926200e-07
0.3703511.7441222.882568e-07
0.3722941.7435572.641347e-07
0.3742471.7429992.398860e-07
0.376211.7424482.155102e-07
0.3781831.7419041.910065e-07
0.381.7414111.684500e-07
0.3801671.7413661.674776e-07
0.3821611.7408361.558776e-07
0.3841661.7403121.442167e-07
0.3861811.7397941.324947e-07
0.3882071.7392831.207112e-07
0.391.7388381.102800e-07
0.3902431.7387791.094156e-07
0.392291.738281.021375e-07
0.3943481.7377889.482116e-08
0.3964161.7373018.746647e-08
0.3984961.7368218.007319e-08
0.41.7364797.472500e-08
0.4005861.7363467.339913e-08
0.4026871.7358786.864565e-08
0.40481.7354156.386724e-08
0.4051.7353716.341400e-08
0.4069231.7349576.050474e-08
0.4090581.7345055.727552e-08
0.4112031.7340595.402936e-08
0.413361.7336175.076617e-08
0.4155281.7331824.748587e-08
0.4177081.7327514.418836e-08
0.4198991.7323254.087355e-08
0.421.7323064.072100e-08
0.4221021.7319053.924112e-08
0.4243161.7314893.768210e-08
0.4265421.7310793.611490e-08
0.4287791.7306733.453948e-08
0.4310281.7302723.295580e-08
0.4332891.7298753.136381e-08
0.4355621.7294842.976347e-08
0.4361.7294092.945500e-08
0.4378471.7290962.866287e-08
0.4401431.7287142.767768e-08
0.4424521.7283362.668731e-08
0.4447731.7279622.569176e-08
0.4471061.7275922.469098e-08
0.4494511.7272272.368495e-08
0.4518091.7268662.267364e-08
0.4541791.7265092.165703e-08
0.4565611.7261562.063509e-08
0.4589561.7258071.960779e-08
0.461.7256561.916000e-08
0.4613641.7254621.883337e-08
0.4637841.7251211.825364e-08
0.4662161.7247831.767088e-08
0.4686621.724451.708506e-08
0.471121.724121.649617e-08
0.4735921.7237941.590419e-08
0.4760761.7234721.530910e-08
0.4785731.7231531.471089e-08
0.4810831.7228381.410955e-08
0.4836071.7225261.350505e-08
0.4861441.7222181.289738e-08
0.4886941.7219131.228652e-08
0.4912571.7216111.167245e-08
0.4938341.7213131.105517e-08
0.4964241.7210181.043465e-08
0.4990281.7207269.810870e-09
0.51.7206189.578100e-09
0.5016461.7204379.547099e-09
0.5042771.7201519.497538e-09
0.5069221.7198699.447717e-09
0.5095821.7195899.397634e-09
0.5122551.7193139.347289e-09
0.5149421.7190399.296679e-09
0.5176431.7187699.245805e-09
0.5203581.7185019.194663e-09
0.5230871.7182369.143253e-09
0.5258311.7179749.091573e-09
0.528591.7177149.039622e-09
0.5313621.7174588.987399e-09
0.5341491.7172048.934902e-09
0.5369511.7169528.882129e-09
0.5397681.7167038.829080e-09
0.5425991.7164578.775752e-09
0.5454451.7162138.722145e-09
0.5461.7161668.711700e-09
0.5483071.7159728.874468e-09
0.5511831.7157339.077430e-09
0.5540741.7154979.281456e-09
0.556981.7152639.486552e-09
0.5599021.7150329.692725e-09
0.5628391.7148029.899978e-09
0.5657911.7145761.010832e-08
0.5687591.7143511.031775e-08
0.5717421.7141281.052829e-08
0.5747421.7139081.073992e-08
0.5777561.713691.095267e-08
0.581.713531.111100e-08
0.5807871.7134741.112607e-08
0.5838331.713261.118441e-08
0.5868961.7130491.124306e-08
0.5899741.7128391.130201e-08
0.5930691.7126311.136127e-08
0.596181.7124261.142085e-08
0.5993071.7122221.148074e-08
0.6024511.712021.154094e-08
0.6056111.7118211.160145e-08
0.6087881.7116231.166229e-08
0.6119811.7114271.172344e-08
0.6151911.7112321.178491e-08
0.6184181.711041.184671e-08
0.621.7109471.187700e-08
0.6216621.7108491.182107e-08
0.6249231.710661.171134e-08
0.6282011.7104731.160103e-08
0.6314961.7102881.149015e-08
0.6348091.7101041.137868e-08
0.6381391.7099221.126663e-08
0.6414861.7097421.115399e-08
0.6448511.7095631.104077e-08
0.6482341.7093851.092694e-08
0.6516341.709211.081252e-08
0.6550521.7090351.069750e-08
0.6584881.7088631.058188e-08
0.661.7087881.053100e-08
0.6619421.7086921.045329e-08
0.6654141.7085221.031436e-08
0.6689051.7083541.017470e-08
0.6724131.7081871.003431e-08
0.6759411.7080229.893180e-09
0.6794861.7078579.751310e-09
0.683051.7076959.608697e-09
0.6866331.7075349.465335e-09
0.6902351.7073749.321221e-09
0.6938561.7072159.176352e-09
0.6974951.7070579.030722e-09
0.71.706958.930500e-09
0.7011541.7069018.966959e-09
0.7048321.7067469.083165e-09
0.7085291.7065939.199980e-09
0.7122461.706449.317408e-09
0.7159821.7062899.435452e-09
0.7197371.7061399.554116e-09
0.7235131.705999.673401e-09
0.7273081.7058429.793313e-09
0.7311231.7056959.913853e-09
0.7349581.705551.003503e-08
0.7388131.7054051.015683e-08
0.7426891.7052611.027928e-08
0.7465841.7051191.040237e-08
0.7505011.7049771.052611e-08
0.7544371.7048371.065049e-08
0.7583951.7046971.077553e-08
0.7623731.7045591.090122e-08
0.7663721.7044211.102757e-08
0.7703921.7042851.115459e-08
0.7744331.7041491.128227e-08
0.7784951.7040141.141062e-08
0.7825791.703881.153964e-08
0.7866841.7037471.166934e-08
0.790811.7036151.179972e-08
0.7949581.7034831.193079e-08
0.7991281.7033531.206254e-08
0.803321.7032231.219499e-08
0.8075341.7030941.232812e-08
0.811771.7029661.246196e-08
0.8160281.7028381.259650e-08
0.8203081.7027111.273174e-08
0.8246111.7025851.286770e-08
0.8289371.702461.300436e-08
0.8332851.7023351.314175e-08
0.8376561.7022111.327985e-08
0.842051.7020881.341868e-08
0.8464671.7019661.355824e-08
0.8509071.7018431.369853e-08
0.855371.7017221.383955e-08
0.8598571.7016011.398132e-08
0.8643671.7014811.412383e-08
0.8689011.7013611.426708e-08
0.8734591.7012421.441109e-08
0.8780411.7011241.455585e-08
0.8826471.7010061.470138e-08
0.8872771.7008881.484766e-08
0.8919311.7007711.499471e-08
0.8966091.7006551.514254e-08
0.9013131.7005391.529114e-08
0.906041.7004231.544052e-08
0.9107931.7003081.559068e-08
0.9155711.7001931.574163e-08
0.9203731.7000791.589337e-08
0.9252011.6999651.604591e-08
0.9300541.6998521.619925e-08
0.9349331.6997381.635339e-08
0.9398371.6996261.650834e-08
0.9447671.6995131.666411e-08
0.9497221.6994011.682069e-08
0.9547041.6992891.697809e-08
0.9597121.6991781.713632e-08
0.9647461.6990671.729538e-08
0.9698071.6989561.745527e-08
0.9748941.6988451.761600e-08
0.9800081.6987351.777757e-08
0.9851481.6986251.793999e-08
0.9903161.6985151.810327e-08
0.995511.6984061.826740e-08
1.000731.6982961.843239e-08
1.005981.6981871.859825e-08
1.011261.6980781.876497e-08
1.016561.6979691.893257e-08
1.02191.697861.910105e-08
1.027261.6977521.927042e-08
1.032641.6976431.944067e-08
1.038061.6975351.961182e-08
1.043511.6974271.978386e-08
1.048981.6973181.995680e-08
1.054481.697212.013066e-08
1.061.6971032.030500e-08
1.060011.6971022.030736e-08
1.065571.6969942.128993e-08
1.071161.6968862.227765e-08
1.076781.6967782.327056e-08
1.082431.6966712.426867e-08
1.088111.6965632.527202e-08
1.093821.6964552.628064e-08
1.099551.6963472.729454e-08
1.105321.6962392.831376e-08
1.111121.6961312.933833e-08
1.116951.6960233.036827e-08
1.122811.6959153.140362e-08
1.12871.6958063.244439e-08
1.134621.6956983.349063e-08
1.140571.6955893.454235e-08
1.146551.6954813.559959e-08
1.152561.6953723.666238e-08
1.158611.6952633.773074e-08
1.164691.6951543.880470e-08
1.17081.6950453.988430e-08
1.176941.6949354.096956e-08
1.183111.6948264.206052e-08
1.189321.6947164.315719e-08
1.195561.6946064.425962e-08
1.201831.6944954.536784e-08
1.208131.6943854.648186e-08
1.214471.6942744.760173e-08
1.220841.6941634.872747e-08
1.227241.6940514.985912e-08
1.233681.6939395.099670e-08
1.240151.6938275.214026e-08
1.246661.6937155.328981e-08
1.25321.6936025.444538e-08
1.259771.6934895.560703e-08
1.266381.6933755.677476e-08
1.273021.6932615.794862e-08
1.27971.6931475.912864e-08
1.286411.6930326.031484e-08
1.293161.6929176.150727e-08
1.299941.6928016.270596e-08
1.306761.6926856.391093e-08
1.313621.6925686.512222e-08
1.320511.6924516.633987e-08
1.327431.6923346.756390e-08
1.33441.6922166.879435e-08
1.34141.6920977.003126e-08
1.348431.6919787.127466e-08
1.355511.6918587.252458e-08
1.362621.6917377.378105e-08
1.369761.6916167.504412e-08
1.376951.6914957.631381e-08
1.384171.6913737.759016e-08
1.391431.691257.887321e-08
1.398731.6911268.016298e-08
1.406071.6910028.145953e-08
1.413441.6908778.276287e-08
1.420861.6907528.407305e-08
1.428311.6906258.539010e-08
1.43581.6904988.671406e-08
1.443331.6903718.804497e-08
1.45091.6902428.938285e-08
1.458521.6901139.072776e-08
1.466171.6899839.207972e-08
1.473861.6898529.343877e-08
1.481591.689729.480495e-08
1.489361.6895879.617830e-08
1.497171.6894549.755885e-08
1.505031.689329.894664e-08
1.512921.6891841.003417e-07
1.520861.6890481.017441e-07
1.528831.6889111.031538e-07
1.531.6888911.033600e-07
1.536851.6887731.142350e-07
1.544911.6886341.270281e-07
1.553021.6884941.398882e-07
1.561161.6883531.528159e-07
1.569351.6882111.658114e-07
1.577591.6880681.788750e-07
1.585861.6879241.920071e-07
1.594181.6877792.052082e-07
1.602541.6876332.184784e-07
1.610951.6874852.318183e-07
1.61941.6873372.452282e-07
1.627891.6871872.587084e-07
1.636431.6870362.722593e-07
1.645021.6868842.858813e-07
1.653641.6867312.995748e-07
1.662321.6865763.133400e-07
1.671041.6864213.271775e-07
1.67981.6862643.410876e-07
1.688611.6861053.550706e-07
1.697471.6859463.691270e-07
1.706381.6857853.832571e-07
1.715331.6856223.974613e-07
1.724321.6854594.117401e-07
1.733371.6852934.260937e-07
1.742461.6851274.405227e-07
1.75161.6849594.550273e-07
1.760791.684794.696080e-07
1.770031.6846194.842652e-07
1.779311.6844464.989992e-07
1.788641.6842725.138106e-07
1.798031.6840975.286996e-07
1.807461.6839195.436668e-07
1.816941.6837415.587124e-07
1.826471.683565.738370e-07
1.836051.6833785.890409e-07
1.845681.6831946.043246e-07
1.855361.6830096.196884e-07
1.865091.6828226.351328e-07
1.874881.6826336.506583e-07
1.884711.6824426.662652e-07
1.89461.6822496.819539e-07
1.904541.6820556.977249e-07
1.914531.6818597.135787e-07
1.924571.6816617.295156e-07
1.934671.681467.455362e-07
1.944811.6812587.616407e-07
1.955011.6810547.778297e-07
1.965271.6808487.941037e-07
1.971.6807538.016100e-07
1.975581.680648.899025e-07
1.985941.680431.053912e-06
1.996361.6802181.218783e-06
2.006831.6800031.384518e-06
2.017361.6797871.551122e-06
2.027941.6795681.718601e-06
2.038581.6793471.886958e-06
2.049271.6791232.056198e-06
2.060021.6788982.226325e-06
2.070831.678672.397346e-06
2.081691.6784392.569263e-06
2.092611.6782072.742082e-06
2.103581.6779722.915807e-06
2.114621.6777343.090444e-06
2.125711.6774943.265997e-06
2.136861.6772513.442471e-06
2.148071.6770063.619870e-06
2.159341.6767583.798200e-06
2.170661.6765083.977465e-06
2.182051.6762544.157671e-06
2.19351.6759984.338822e-06
2.2051.675744.520923e-06
2.216571.6754784.703980e-06
2.22821.6752144.887996e-06
2.239881.6749475.072978e-06
2.251631.6746765.258930e-06
2.263441.6744035.445858e-06
2.275321.6741275.633766e-06
2.287251.6738485.822660e-06
2.299251.6735656.012545e-06
2.311311.673286.203425e-06
2.323431.6729916.395307e-06
2.3251.6729536.420100e-06
2.335621.6726997.142503e-06
2.347871.6724047.975804e-06
2.360191.6721058.813476e-06
2.372571.6718039.655542e-06
2.385011.6714971.050202e-05
2.397521.6711881.135295e-05
2.41011.6708761.220833e-05
2.422741.670561.306821e-05
2.435451.670241.393259e-05
2.448231.6699161.480151e-05
2.461071.6695891.567499e-05
2.473981.6692581.655304e-05
2.486951.6689231.743571e-05
2.51.6685841.832300e-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
—