Optical constants

Refractive index of N-BAK2 (SCHOTT)

N-BAK2: 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.

At one wavelength

Range 0.3–2.5 µm
Refractive index n
1.53996
Extinction coefficient k
9.75245e-09
Permittivity ε1
2.37147
Permittivity ε2
3.00367e-08
Absorption coefficient α
0.00208565 cm⁻¹
Penetration depth δ = λ/(2πk)
9.58933e+09 nm
Abbe number Vd
59.709
Chromatic dispersion dn/dλ
-0.0467064 µm⁻¹
Group index ng
1.5674
Group velocity dispersion
81.8288 fs²/mm
Dispersion parameter D
-446.419 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-BAK2 (SCHOTT): N-BAK2
schott_n_bak2 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-BAK2", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_bak2.range_nm)  # (300, 2500) nm
eps = schott_n_bak2.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=1.01662154λ2λ2−0.00592383763+0.319903051λ2λ2−0.0203828415+0.937232995λ2λ2−113.118417

Valid from 0.3 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.01662154
C30.00592383763
C40.319903051
C50.0203828415
C60.937232995
C7113.118417

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: -1.45e-06 1.1e-08 4.89e-12 5.16e-07 3.05e-10 0.164
nd
1.53996
Vd
59.71
glass code
540597.286
glass status
standard
density
value: 2860
thermal expansion
value: 8e-06, temperature range: 243 343; value: 9e-06, temperature range: 293 573
dPgF
0.0004
resistance
acid: 1.0; stain: 0.0; alkali: 1.0; climatic: 2.0; phosphate: 2.3

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = -3.09e-08 K⁻¹ at 633 nm, dn/dT = -4.98e-07 K⁻¹ at 1310 nm, dn/dT = -5.35e-07 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 423 wavelengths, the same grid as the API and the library
N-BAK2 (SCHOTT), N-BAK2: n and k versus wavelength
λ (µm)nk
0.31.5814772.198800e-06
0.3015981.5808151.991861e-06
0.3032051.5801621.783820e-06
0.3048211.5795191.574670e-06
0.3064451.5788851.364406e-06
0.3080781.5782591.153022e-06
0.3097191.5776439.405112e-07
0.311.5775399.041600e-07
0.3113691.5770358.300945e-07
0.3130281.5764367.403672e-07
0.3146961.5758456.501620e-07
0.3163731.5752625.594760e-07
0.3180591.5746884.683070e-07
0.3197531.5741213.766521e-07
0.321.5740393.633100e-07
0.3214571.5735623.359353e-07
0.323171.5730113.037552e-07
0.3248921.5724672.714036e-07
0.3266231.5719312.388796e-07
0.3283631.5714022.061823e-07
0.3301121.570881.733108e-07
0.3318711.5703651.402642e-07
0.333641.5698571.070415e-07
0.3341.5697551.002700e-07
0.3354171.5693569.429238e-08
0.3372041.5688618.675470e-08
0.3390011.5683737.917686e-08
0.3408071.5678927.155864e-08
0.3426231.5674176.389984e-08
0.3444491.5669485.620022e-08
0.3462841.5664854.845959e-08
0.3481291.5660294.067771e-08
0.3499841.5655783.285437e-08
0.351.5655743.278600e-08
0.3518491.5651333.076432e-08
0.3537231.5646942.871404e-08
0.3556081.5642612.665284e-08
0.3575031.5638332.458066e-08
0.3594071.563412.249744e-08
0.3613221.5629932.040312e-08
0.3632481.5625821.829764e-08
0.3651.5622141.638100e-08
0.3651831.5621761.625829e-08
0.3671291.5617741.495310e-08
0.3690851.5613781.364095e-08
0.371.5611951.302700e-08
0.3710511.5609871.293554e-08
0.3730281.5606011.276354e-08
0.3750161.560221.259063e-08
0.3770141.5598431.241679e-08
0.3790231.5594711.224203e-08
0.381.5592931.215700e-08
0.3810421.5591041.192921e-08
0.3830721.5587421.148544e-08
0.3851131.5583831.103931e-08
0.3871651.558031.059081e-08
0.3892281.557681.013991e-08
0.391.5575519.971200e-09
0.3913021.5573359.837458e-09
0.3933871.5569949.623298e-09
0.3954831.5566589.407997e-09
0.397591.5563259.191548e-09
0.3997081.5559978.973947e-09
0.41.5559528.944000e-09
0.4018381.5556728.985101e-09
0.4039791.5553529.032974e-09
0.4051.5552019.055800e-09
0.4061321.5550359.081103e-09
0.4082961.5547229.129488e-09
0.4104711.5544139.178130e-09
0.4126581.5541079.227032e-09
0.4148571.5538069.276195e-09
0.4170671.5535089.325619e-09
0.4192891.5532139.375307e-09
0.421.553129.391200e-09
0.4215231.5529229.558355e-09
0.4237691.5526349.804816e-09
0.4260271.552351.005259e-08
0.4282971.5520691.030168e-08
0.4305791.5517911.055211e-08
0.4328731.5515171.080386e-08
0.4351791.5512461.105696e-08
0.4361.551151.114700e-08
0.4374981.5509781.118533e-08
0.4398291.5507131.124496e-08
0.4421731.5504511.130492e-08
0.4445291.5501921.136519e-08
0.4468971.5499361.142578e-08
0.4492781.5496831.148670e-08
0.4516721.5494331.154794e-08
0.4540781.5491861.160951e-08
0.4564981.5489421.167140e-08
0.458931.5487011.173363e-08
0.461.5485961.176100e-08
0.4613751.5484621.168594e-08
0.4638341.5482261.155179e-08
0.4663051.5479931.141692e-08
0.4687891.5477621.128134e-08
0.4712871.5475341.114503e-08
0.4737981.5473081.100799e-08
0.4763231.5470851.087023e-08
0.4788611.5468651.073173e-08
0.4814121.5466471.059249e-08
0.4839771.5464311.045251e-08
0.4865561.5462181.031179e-08
0.4891481.5460071.017032e-08
0.4917541.5457981.002809e-08
0.4943741.5455929.885102e-09
0.4970081.5453889.741354e-09
0.4996571.5451869.596840e-09
0.51.545169.578100e-09
0.5023191.5449869.534426e-09
0.5049951.5447899.484016e-09
0.5076861.5445949.433338e-09
0.5103911.5444019.382390e-09
0.513111.544219.331171e-09
0.5158441.5440219.279678e-09
0.5185931.5438349.227912e-09
0.5213561.5436499.175869e-09
0.5241341.5434659.123549e-09
0.5269261.5432849.070951e-09
0.5297341.5431059.018072e-09
0.5325561.5429288.964911e-09
0.5353941.5427538.911468e-09
0.5382461.5425798.857739e-09
0.5411141.5424078.803724e-09
0.5439971.5422378.749422e-09
0.5461.5421218.711700e-09
0.5468961.5420698.725989e-09
0.549811.5419038.772474e-09
0.5527391.5417388.819208e-09
0.5556841.5415758.866190e-09
0.5586451.5414148.913422e-09
0.5616211.5412548.960906e-09
0.5646141.5410969.008643e-09
0.5676221.5409399.056635e-09
0.5706461.5407849.104882e-09
0.5736871.5406319.153386e-09
0.5767431.5404799.202149e-09
0.5798161.5403299.251171e-09
0.581.540329.254100e-09
0.5829061.540189.444635e-09
0.5860111.5400339.648288e-09
0.5891341.5398879.853026e-09
0.5922731.5397431.005886e-08
0.5954281.53961.026578e-08
0.5986011.5394581.047381e-08
0.601791.5393181.068295e-08
0.6049971.5391791.089320e-08
0.608221.5390411.110457e-08
0.6114611.5389051.131707e-08
0.6147191.538771.153070e-08
0.6179941.5386371.174546e-08
0.621.5385561.187700e-08
0.6212871.5385041.183370e-08
0.6245971.5383731.172231e-08
0.6279251.5382431.161033e-08
0.6312711.5381141.149774e-08
0.6346341.5379871.138456e-08
0.6380151.5378611.127078e-08
0.6414151.5377361.115639e-08
0.6448321.5376121.104139e-08
0.6482681.5374891.092578e-08
0.6517221.5373671.080955e-08
0.6551951.5372461.069270e-08
0.6586851.5371271.057523e-08
0.661.5370821.053100e-08
0.6621951.5370081.044317e-08
0.6657231.5368911.030200e-08
0.669271.5367741.016007e-08
0.6728361.5366591.001739e-08
0.6764211.5365449.873949e-09
0.6800251.5364319.729743e-09
0.6836481.5363189.584768e-09
0.6872911.5362079.439021e-09
0.6909531.5360969.292498e-09
0.6946341.5359879.145193e-09
0.6983351.5358788.997104e-09
0.71.535838.930500e-09
0.7020561.535778.937391e-09
0.7057971.5356638.949927e-09
0.7095571.5355578.962530e-09
0.7133381.5354528.975201e-09
0.7171391.5353488.987938e-09
0.720961.5352449.000744e-09
0.7248011.5351419.013618e-09
0.7286631.535049.026560e-09
0.7325451.5349389.039572e-09
0.7364481.5348389.052652e-09
0.7403721.5347399.065803e-09
0.7443171.534649.079023e-09
0.7482831.5345429.092314e-09
0.752271.5344449.105676e-09
0.7562781.5343489.119109e-09
0.7603071.5342529.132613e-09
0.7643581.5341579.146189e-09
0.7684311.5340629.159838e-09
0.7725251.5339689.173560e-09
0.7766411.5338759.187354e-09
0.7807791.5337829.201222e-09
0.7849391.533699.215164e-09
0.7891211.5335999.229181e-09
0.7933261.5335089.243272e-09
0.7975531.5334189.257438e-09
0.8018021.5333299.271679e-09
0.8060741.533249.285996e-09
0.8103691.5331519.300390e-09
0.8146871.5330649.314860e-09
0.8190281.5329769.329408e-09
0.8233911.532899.344033e-09
0.8277791.5328039.358736e-09
0.8321891.5327189.373517e-09
0.8366231.5326329.388377e-09
0.8410811.5325489.403316e-09
0.8455621.5324639.418335e-09
0.8500671.532389.433434e-09
0.8545961.5322969.448613e-09
0.859151.5322139.463873e-09
0.8637271.5321319.479214e-09
0.8683291.5320499.494638e-09
0.8729561.5319679.510143e-09
0.8776071.5318869.525731e-09
0.8822831.5318059.541402e-09
0.8869841.5317259.557156e-09
0.891711.5316459.572995e-09
0.8964611.5315659.588917e-09
0.9012381.5314869.604925e-09
0.9060391.5314079.621018e-09
0.9108671.5313299.637197e-09
0.915721.531259.653462e-09
0.9205991.5311729.669813e-09
0.9255041.5310959.686252e-09
0.9304351.5310179.702778e-09
0.9353931.530949.719392e-09
0.9403771.5308649.736095e-09
0.9453871.5307879.752887e-09
0.9504241.5307119.769768e-09
0.9554881.5306359.786740e-09
0.9605791.5305599.803801e-09
0.9656971.5304849.820954e-09
0.9708421.5304099.838198e-09
0.9760151.5303349.855534e-09
0.9812151.5302599.872962e-09
0.9864431.5301849.890483e-09
0.9916991.530119.908097e-09
0.9969831.5300359.925806e-09
1.00231.5299619.943608e-09
1.007641.5298889.961506e-09
1.0131.5298149.979499e-09
1.01841.529749.997587e-09
1.023831.5296671.001577e-08
1.029281.5295931.003405e-08
1.034771.529521.005243e-08
1.040281.5294471.007091e-08
1.045821.5293741.008949e-08
1.05141.5293011.010816e-08
1.0571.5292281.012694e-08
1.061.5291891.013700e-08
1.062631.5291561.051965e-08
1.068291.5290831.134380e-08
1.073981.529011.217234e-08
1.07971.5289381.300530e-08
1.085461.5288651.384269e-08
1.091241.5287931.468455e-08
1.097061.528721.553089e-08
1.10291.5286481.638174e-08
1.108781.5285751.723712e-08
1.114681.5285031.809707e-08
1.120621.528431.896159e-08
1.126591.5283581.983072e-08
1.13261.5282852.070448e-08
1.138631.5282132.158290e-08
1.14471.528142.246599e-08
1.15081.5280682.335379e-08
1.156931.5279952.424633e-08
1.163091.5279222.514361e-08
1.169291.5278492.604568e-08
1.175521.5277762.695255e-08
1.181781.5277032.786426e-08
1.188081.527632.878082e-08
1.194411.5275572.970227e-08
1.200771.5274833.062863e-08
1.207171.527413.155992e-08
1.21361.5273363.249618e-08
1.220071.5272623.343742e-08
1.226571.5271883.438368e-08
1.233111.5271143.533498e-08
1.239681.527043.629135e-08
1.246281.5269653.725281e-08
1.252921.526893.821940e-08
1.25961.5268153.919113e-08
1.266311.526744.016805e-08
1.273061.5266654.115017e-08
1.279841.5265894.213752e-08
1.286661.5265134.313013e-08
1.293511.5264374.412804e-08
1.30041.5263614.513125e-08
1.307331.5262844.613982e-08
1.31431.5262074.715376e-08
1.32131.526134.817310e-08
1.328341.5260534.919787e-08
1.335421.5259755.022810e-08
1.342531.5258975.126382e-08
1.349691.5258185.230506e-08
1.356881.5257395.335184e-08
1.364111.525665.440421e-08
1.371381.5255815.546218e-08
1.378681.5255015.652579e-08
1.386031.5254215.759506e-08
1.393411.525345.867003e-08
1.400841.5252595.975073e-08
1.40831.5251776.083719e-08
1.415811.5250966.192944e-08
1.423351.5250136.302750e-08
1.430931.5249316.413142e-08
1.438561.5248476.524122e-08
1.446221.5247646.635693e-08
1.453931.524686.747859e-08
1.461671.5245956.860622e-08
1.469461.524516.973986e-08
1.477291.5244247.087954e-08
1.485161.5243387.202529e-08
1.493081.5242527.317715e-08
1.501031.5241657.433515e-08
1.509031.5240777.549931e-08
1.517071.5239897.666968e-08
1.525151.52397.784628e-08
1.531.5238477.855200e-08
1.533281.5238118.555903e-08
1.541451.5237211.030221e-07
1.549661.523631.205782e-07
1.557921.5235391.382279e-07
1.566221.5234471.559716e-07
1.574561.5233551.738098e-07
1.582951.5232621.917431e-07
1.591391.5231682.097719e-07
1.599871.5230732.278968e-07
1.608391.5229782.461182e-07
1.616961.5228832.644368e-07
1.625571.5227862.828529e-07
1.634241.5226893.013672e-07
1.642941.5225913.199801e-07
1.65171.5224923.386922e-07
1.66051.5223933.575040e-07
1.669341.5222933.764160e-07
1.678241.5221923.954288e-07
1.687181.522094.145428e-07
1.696171.5219874.337588e-07
1.705211.5218844.530771e-07
1.714291.521784.724983e-07
1.723431.5216754.920230e-07
1.732611.5215695.116518e-07
1.741841.5214625.313851e-07
1.751121.5213545.512236e-07
1.760451.5212465.711677e-07
1.769831.5211365.912182e-07
1.779261.5210266.113754e-07
1.788741.5209146.316401e-07
1.798271.5208026.520127e-07
1.807851.5206886.724939e-07
1.817491.5205746.930842e-07
1.827171.5204597.137842e-07
1.83691.5203427.345946e-07
1.846691.5202257.555157e-07
1.856531.5201067.765484e-07
1.866421.5199877.976931e-07
1.876371.5198668.189505e-07
1.886371.5197448.403211e-07
1.896421.5196218.618056e-07
1.906521.5194978.834046e-07
1.916681.5193729.051187e-07
1.926891.5192469.269484e-07
1.937161.5191189.488945e-07
1.947481.518999.709575e-07
1.957851.518869.931380e-07
1.968291.5187281.015437e-06
1.971.5187071.019100e-06
1.978771.5185961.078421e-06
1.989321.5184621.149707e-06
1.999921.5183271.221373e-06
2.010571.5181911.293421e-06
2.021281.5180531.365852e-06
2.032051.5179141.438670e-06
2.042881.5177741.511876e-06
2.053771.5176321.585471e-06
2.064711.5174891.659459e-06
2.075711.5173441.733841e-06
2.086771.5171981.808619e-06
2.097891.517051.883795e-06
2.109061.5169011.959373e-06
2.12031.5167512.035352e-06
2.13161.5165992.111737e-06
2.142961.5164452.188529e-06
2.154371.516292.265730e-06
2.165851.5161332.343342e-06
2.177391.5159742.421367e-06
2.188991.5158142.499809e-06
2.200661.5156522.578668e-06
2.212381.5154892.657948e-06
2.224171.5153232.737650e-06
2.236021.5151562.817776e-06
2.247931.5149882.898330e-06
2.259911.5148172.979312e-06
2.271951.5146453.060727e-06
2.284061.514473.142574e-06
2.296231.5142943.224859e-06
2.308461.5141163.307581e-06
2.320761.5139363.390744e-06
2.3251.5138743.419400e-06
2.333131.5137553.516762e-06
2.345561.5135713.665687e-06
2.358061.5133853.815405e-06
2.370621.5131973.965921e-06
2.383251.5130074.117239e-06
2.395951.5128154.269363e-06
2.408711.5126214.422297e-06
2.421551.5124244.576047e-06
2.434451.5122264.730616e-06
2.447421.5120254.886008e-06
2.460461.5118225.042228e-06
2.473571.5116175.199280e-06
2.486751.5114095.357170e-06
2.51.5111995.515900e-06

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
—