Optical constants

Refractive index of N-LAK9 (SCHOTT)

N-LAK9: n,k 0.3–2.5 µm

Data
formula 2 + tabulated k
Range
0.3–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength. Note: k data cover 320-2500 nm only; k = 0 elsewhere in the n range 300-2500 nm.

At one wavelength

Range 0.3–2.5 µm
Refractive index n
1.691
Extinction coefficient k
1.08795e-08
Permittivity ε1
2.85948
Permittivity ε2
3.67943e-08
Absorption coefficient α
0.00232667 cm⁻¹
Penetration depth δ = λ/(2πk)
8.59596e+09 nm
Abbe number Vd
54.708
Chromatic dispersion dn/dλ
-0.0652171 µm⁻¹
Group index ng
1.72932
Group velocity dispersion
114.028 fs²/mm
Dispersion parameter D
-622.081 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-LAK9 (SCHOTT): N-LAK9
schott_n_lak9 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-LAK9", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_lak9.range_nm)  # (300, 2500) nm
eps = schott_n_lak9.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=1.46231905λ2λ2−0.00724270156+0.344399589λ2λ2−0.0243353131+1.15508372λ2λ2−85.4686868

Valid from 0.3 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.46231905
C30.00724270156
C40.344399589
C50.0243353131
C61.15508372
C785.4686868

Comments and conditions

step 0.5 available

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 2.11e-06 1.11e-08 1.82e-12 4.74e-07 -3.47e-10 0.146
nd
1.691
Vd
54.71
glass code
691547.351
glass status
standard
density
value: 3510
thermal expansion
value: 6.3e-06, temperature range: 243 343; value: 7.5e-06, temperature range: 293 573
dPgF
-0.0071
resistance
acid: 52.0; stain: 3.0; alkali: 1.2; climatic: 3.0; phosphate: 4.3

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = 1.84e-06 K⁻¹ at 633 nm, dn/dT = 1.28e-06 K⁻¹ at 1310 nm, dn/dT = 1.23e-06 K⁻¹ at 1550 nm
Notes on the source data (kept exactly as published):
  • k data cover 320-2500 nm only; k = 0 elsewhere in the n range 300-2500 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-LAK9 (SCHOTT), N-LAK9: n and k versus wavelength
λ (µm)nk
0.31.7496040
0.3015981.7486530
0.3032051.7477170
0.3048211.7467950
0.3064451.7458860
0.3080781.7449910
0.3097191.7441090
0.3113691.743240
0.3130281.7423840
0.3146961.741540
0.3163731.7407080
0.3180591.7398880
0.3197531.739080
0.321.7389643.984800e-06
0.3214571.7382843.748175e-06
0.323171.7374983.470012e-06
0.3248921.7367243.190367e-06
0.3266231.7359612.909232e-06
0.3283631.7352092.626599e-06
0.3301121.7344672.342460e-06
0.3318711.7337352.056807e-06
0.333641.7330131.769633e-06
0.3341.7328681.711100e-06
0.3354171.7323021.618530e-06
0.3372041.73161.501801e-06
0.3390011.7309081.384451e-06
0.3408071.7302251.266475e-06
0.3426231.7295521.147870e-06
0.3444491.7288871.028634e-06
0.3462841.7282329.087618e-07
0.3481291.7275867.882513e-07
0.3499841.7269486.670987e-07
0.351.7269426.660400e-07
0.3518491.7263186.191673e-07
0.3537231.7256985.716317e-07
0.3556081.7250855.238428e-07
0.3575031.724484.757992e-07
0.3594071.7238844.274997e-07
0.3613221.7232953.789429e-07
0.3632481.7227143.301273e-07
0.3651.7221942.856900e-07
0.3651831.722142.832666e-07
0.3671291.7215742.574896e-07
0.3690851.7210162.315753e-07
0.371.7207582.194500e-07
0.3710511.7204642.111987e-07
0.3730281.719921.956812e-07
0.3750161.7193821.800811e-07
0.3770141.7188521.643979e-07
0.3790231.7183281.486311e-07
0.381.7180771.409600e-07
0.3810421.7178111.356587e-07
0.3830721.71731.253309e-07
0.3851131.7167961.149481e-07
0.3871651.7162991.045100e-07
0.3892281.7158079.401632e-08
0.391.7156269.009000e-08
0.3913021.7153228.686350e-08
0.3933871.7148438.169693e-08
0.3954831.714377.650283e-08
0.397591.7139027.128106e-08
0.3997081.7134416.603146e-08
0.41.7133786.530900e-08
0.4018381.7129856.212975e-08
0.4039791.7125345.842662e-08
0.4051.7123235.666100e-08
0.4061321.712095.545848e-08
0.4082961.711655.315897e-08
0.4104711.7112175.084721e-08
0.4126581.7107884.852313e-08
0.4148571.7103644.618667e-08
0.4170671.7099464.383776e-08
0.4192891.7095334.147633e-08
0.421.7094024.072100e-08
0.4215231.7091253.991864e-08
0.4237691.7087213.873561e-08
0.4260271.7083233.754627e-08
0.4282971.7079293.635060e-08
0.4305791.707543.514855e-08
0.4328731.7071553.394010e-08
0.4351791.7067763.272521e-08
0.4361.7066423.229300e-08
0.4374981.70643.175142e-08
0.4398291.7060293.090875e-08
0.4421731.7056623.006160e-08
0.4445291.70532.920992e-08
0.4468971.7049422.835372e-08
0.4492781.7045882.749295e-08
0.4516721.7042382.662759e-08
0.4540781.7038922.575762e-08
0.4564981.7035512.488302e-08
0.458931.7032132.400376e-08
0.461.7030662.361700e-08
0.4613751.7028792.324452e-08
0.4638341.7025492.257877e-08
0.4663051.7022222.190946e-08
0.4687891.70192.123660e-08
0.4712871.7015812.056014e-08
0.4737981.7012651.988008e-08
0.4763231.7009531.919640e-08
0.4788611.7006451.850908e-08
0.4814121.700341.781809e-08
0.4839771.7000391.712343e-08
0.4865561.6997411.642506e-08
0.4891481.6994461.572297e-08
0.4917541.6991551.501714e-08
0.4943741.6988661.430755e-08
0.4970081.6985811.359417e-08
0.4996571.6982991.287700e-08
0.51.6982631.278400e-08
0.5023191.6980211.266680e-08
0.5049951.6977451.253152e-08
0.5076861.6974721.239553e-08
0.5103911.6972021.225881e-08
0.513111.6969351.212136e-08
0.5158441.6966711.198318e-08
0.5185931.696411.184426e-08
0.5213561.6961521.170461e-08
0.5241341.6958961.156421e-08
0.5269261.6956431.142306e-08
0.5297341.6953931.128115e-08
0.5325561.6951461.113850e-08
0.5353941.6949011.099508e-08
0.5382461.6946581.085090e-08
0.5411141.6944191.070595e-08
0.5439971.6941811.056023e-08
0.5461.6940191.045900e-08
0.5468961.6939471.047618e-08
0.549811.6937141.053205e-08
0.5527391.6934841.058823e-08
0.5556841.6932571.064471e-08
0.5586451.6930311.070148e-08
0.5616211.6928081.075856e-08
0.5646141.6925881.081595e-08
0.5676221.6923691.087363e-08
0.5706461.6921531.093163e-08
0.5736871.6919391.098994e-08
0.5767431.6917271.104855e-08
0.5798161.6915171.110748e-08
0.581.6915051.111100e-08
0.5829061.6913091.102248e-08
0.5860111.6911041.092786e-08
0.5891341.69091.083274e-08
0.5922731.6906981.073711e-08
0.5954281.6904991.064097e-08
0.5986011.6903011.054432e-08
0.601791.6901051.044716e-08
0.6049971.6899111.034947e-08
0.608221.6897191.025127e-08
0.6114611.6895291.015255e-08
0.6147191.689341.005329e-08
0.6179941.6891549.953511e-09
0.621.6890419.892400e-09
0.6212871.6889699.912943e-09
0.6245971.6887859.965792e-09
0.6279251.6886041.001892e-08
0.6312711.6884241.007233e-08
0.6346341.6882461.012603e-08
0.6380151.688071.018002e-08
0.6414151.6878951.023429e-08
0.6448321.6877211.028885e-08
0.6482681.687551.034370e-08
0.6517221.6873791.039884e-08
0.6551951.6872111.045428e-08
0.6586851.6870431.051001e-08
0.661.6869811.053100e-08
0.6621951.6868781.044317e-08
0.6657231.6867131.030200e-08
0.669271.6865511.016007e-08
0.6728361.6863891.001739e-08
0.6764211.6862299.873949e-09
0.6800251.686079.729743e-09
0.6836481.6859139.584768e-09
0.6872911.6857579.439021e-09
0.6909531.6856029.292498e-09
0.6946341.6854499.145193e-09
0.6983351.6852968.997104e-09
0.71.6852298.930500e-09
0.7020561.6851458.976094e-09
0.7057971.6849969.059037e-09
0.7095571.6848479.142421e-09
0.7133381.68479.226251e-09
0.7171391.6845539.310526e-09
0.720961.6844089.395251e-09
0.7248011.6842649.480428e-09
0.7286631.6841219.566058e-09
0.7325451.683989.652144e-09
0.7364481.6838399.738689e-09
0.7403721.6836999.825695e-09
0.7443171.6835619.913165e-09
0.7482831.6834231.000110e-08
0.752271.6832861.008951e-08
0.7562781.6831511.017838e-08
0.7603071.6830161.026773e-08
0.7643581.6828821.035755e-08
0.7684311.6827491.044786e-08
0.7725251.6826171.053864e-08
0.7766411.6824861.062991e-08
0.7807791.6823561.072167e-08
0.7849391.6822271.081391e-08
0.7891211.6820991.090664e-08
0.7933261.6819711.099987e-08
0.7975531.6818441.109360e-08
0.8018021.6817181.118782e-08
0.8060741.6815931.128255e-08
0.8103691.6814681.137778e-08
0.8146871.6813451.147352e-08
0.8190281.6812221.156977e-08
0.8233911.6810991.166653e-08
0.8277791.6809781.176381e-08
0.8321891.6808571.186161e-08
0.8366231.6807371.195993e-08
0.8410811.6806171.205877e-08
0.8455621.6804981.215814e-08
0.8500671.680381.225803e-08
0.8545961.6802621.235846e-08
0.859151.6801451.245943e-08
0.8637271.6800291.256093e-08
0.8683291.6799131.266297e-08
0.8729561.6797971.276556e-08
0.8776071.6796831.286869e-08
0.8822831.6795681.297238e-08
0.8869841.6794541.307661e-08
0.891711.6793411.318140e-08
0.8964611.6792281.328675e-08
0.9012381.6791161.339266e-08
0.9060391.6790041.349914e-08
0.9108671.6788931.360618e-08
0.915721.6787821.371379e-08
0.9205991.6786711.382198e-08
0.9255041.6785611.393074e-08
0.9304351.6784511.404008e-08
0.9353931.6783411.415001e-08
0.9403771.6782321.426052e-08
0.9453871.6781241.437161e-08
0.9504241.6780151.448331e-08
0.9554881.6779071.459559e-08
0.9605791.6777991.470848e-08
0.9656971.6776921.482196e-08
0.9708421.6775851.493605e-08
0.9760151.6774781.505075e-08
0.9812151.6773711.516606e-08
0.9864431.6772651.528198e-08
0.9916991.6771581.539852e-08
0.9969831.6770521.551569e-08
1.00231.6769461.563347e-08
1.007641.6768411.575189e-08
1.0131.6767351.587093e-08
1.01841.676631.599061e-08
1.023831.6765251.611093e-08
1.029281.676421.623189e-08
1.034771.6763151.635349e-08
1.040281.676211.647574e-08
1.045821.6761061.659864e-08
1.05141.6760011.672220e-08
1.0571.6758971.684641e-08
1.061.6758411.691300e-08
1.062631.6757921.776067e-08
1.068291.6756881.958638e-08
1.073981.6755832.142181e-08
1.07971.6754792.326703e-08
1.085461.6753752.512207e-08
1.091241.6752712.698700e-08
1.097061.6751662.886187e-08
1.10291.6750623.074672e-08
1.108781.6749573.264162e-08
1.114681.6748533.454662e-08
1.120621.6747483.646176e-08
1.126591.6746443.838711e-08
1.13261.6745394.032271e-08
1.138631.6744344.226863e-08
1.14471.6743294.422492e-08
1.15081.6742244.619163e-08
1.156931.6741194.816882e-08
1.163091.6740145.015655e-08
1.169291.6739085.215486e-08
1.175521.6738035.416382e-08
1.181781.6736975.618349e-08
1.188081.6735915.821392e-08
1.194411.6734846.025516e-08
1.200771.6733786.230728e-08
1.207171.6732716.437034e-08
1.21361.6731646.644439e-08
1.220071.6730576.852948e-08
1.226571.6729497.062569e-08
1.233111.6728417.273307e-08
1.239681.6727337.485167e-08
1.246281.6726247.698156e-08
1.252921.6725157.912281e-08
1.25961.6724068.127546e-08
1.266311.6722968.343958e-08
1.273061.6721868.561523e-08
1.279841.6720768.780247e-08
1.286661.6719659.000136e-08
1.293511.6718549.221197e-08
1.30041.6717429.443436e-08
1.307331.671639.666860e-08
1.31431.6715179.891473e-08
1.32131.6714041.011728e-07
1.328341.6712911.034430e-07
1.335421.6711771.057252e-07
1.342531.6710621.080196e-07
1.349691.6709471.103262e-07
1.356881.6708311.126451e-07
1.364111.6707151.149764e-07
1.371381.6705981.173200e-07
1.378681.6704811.196762e-07
1.386031.6703631.220449e-07
1.393411.6702441.244263e-07
1.400841.6701251.268203e-07
1.40831.6700051.292271e-07
1.415811.6698841.316467e-07
1.423351.6697631.340792e-07
1.430931.6696411.365247e-07
1.438561.6695181.389832e-07
1.446221.6693951.414548e-07
1.453931.669271.439395e-07
1.461671.6691451.464375e-07
1.469461.669021.489488e-07
1.477291.6688931.514735e-07
1.485161.6687661.540116e-07
1.493081.6686381.565633e-07
1.501031.6685081.591286e-07
1.509031.6683791.617075e-07
1.517071.6682481.643002e-07
1.525151.6681161.669067e-07
1.531.6680371.684700e-07
1.533281.6679841.742608e-07
1.541451.667851.886929e-07
1.549661.6677152.032019e-07
1.557921.667582.177881e-07
1.566221.6674442.324521e-07
1.574561.6673062.471942e-07
1.582951.6671682.620148e-07
1.591391.6670282.769145e-07
1.599871.6668882.918935e-07
1.608391.6667463.069523e-07
1.616961.6666033.220913e-07
1.625571.6664593.373110e-07
1.634241.6663143.526118e-07
1.642941.6661683.679942e-07
1.65171.6660213.834585e-07
1.66051.6658723.990051e-07
1.669341.6657234.146347e-07
1.678241.6655724.303474e-07
1.687181.665424.461440e-07
1.696171.6652664.620246e-07
1.705211.6651114.779899e-07
1.714291.6649554.940403e-07
1.723431.6647985.101761e-07
1.732611.6646395.263980e-07
1.741841.6644795.427063e-07
1.751121.6643175.591014e-07
1.760451.6641545.755840e-07
1.769831.663995.921543e-07
1.779261.6638246.088129e-07
1.788741.6636566.255603e-07
1.798271.6634876.423969e-07
1.807851.6633176.593233e-07
1.817491.6631456.763398e-07
1.827171.6629716.934470e-07
1.83691.6627967.106453e-07
1.846691.6626197.279352e-07
1.856531.662447.453173e-07
1.866421.662267.627920e-07
1.876371.6620787.803598e-07
1.886371.6618947.980212e-07
1.896421.6617098.157767e-07
1.906521.6615228.336269e-07
1.916681.6613338.515721e-07
1.926891.6611428.696129e-07
1.937161.6609498.877499e-07
1.947481.6607549.059834e-07
1.957851.6605579.243142e-07
1.968291.6603599.427426e-07
1.971.6603269.457700e-07
1.978771.6601581.081063e-06
1.989321.6599551.243644e-06
1.999921.659751.407092e-06
2.010571.6595441.571410e-06
2.021281.6593351.736603e-06
2.032051.6591241.902677e-06
2.042881.658912.069636e-06
2.053771.6586952.237484e-06
2.064711.6584772.406227e-06
2.075711.6582572.575869e-06
2.086771.6580352.746414e-06
2.097891.657812.917869e-06
2.109061.6575833.090236e-06
2.12031.6573543.263522e-06
2.13161.6571223.437732e-06
2.142961.6568883.612870e-06
2.154371.6566513.788940e-06
2.165851.6564113.965949e-06
2.177391.6561694.143901e-06
2.188991.6559244.322801e-06
2.200661.6556774.502655e-06
2.212381.6554274.683466e-06
2.224171.6551744.865241e-06
2.236021.6549195.047985e-06
2.247931.654665.231702e-06
2.259911.6543995.416398e-06
2.271951.6541355.602078e-06
2.284061.6538675.788748e-06
2.296231.6535975.976412e-06
2.308461.6533246.165076e-06
2.320761.6530486.354745e-06
2.3251.6529526.420100e-06
2.333131.6527686.848555e-06
2.345561.6524857.503916e-06
2.358061.6521998.162769e-06
2.370621.651918.825132e-06
2.383251.6516189.491024e-06
2.395951.6513221.016046e-05
2.408711.6510231.083347e-05
2.421551.650721.151006e-05
2.434451.6504131.219026e-05
2.447421.6501041.287408e-05
2.460461.649791.356155e-05
2.473571.6494731.425268e-05
2.486751.6491521.494749e-05
2.51.6488271.564600e-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
—