Optical constants

Refractive index of N-BAK4HT (SCHOTT)

N-BAK4HT: n,k 0.334–2.5 µm

Data
formula 2 + tabulated k
Range
0.334–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.334–2.5 µm
Refractive index n
1.56883
Extinction coefficient k
7.49656e-09
Permittivity ε1
2.46121
Permittivity ε2
2.35216e-08
Absorption coefficient α
0.00160321 cm⁻¹
Penetration depth δ = λ/(2πk)
1.24750e+10 nm
Abbe number Vd
55.976
Chromatic dispersion dn/dλ
-0.0523659 µm⁻¹
Group index ng
1.5996
Group velocity dispersion
92.9662 fs²/mm
Dispersion parameter D
-507.18 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-BAK4HT (SCHOTT): N-BAK4HT
schott_n_bak4ht = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-BAK4HT", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_bak4ht.range_nm)  # (334, 2500) nm
eps = schott_n_bak4ht.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=1.28834642λ2λ2−0.00779980626+0.132817724λ2λ2−0.0315631177+0.945395373λ2λ2−105.965875

Valid from 0.334 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.28834642
C30.00779980626
C40.132817724
C50.0315631177
C60.945395373
C7105.965875

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 3.06e-06 1.44e-08 -2.23e-11 5.46e-07 6.05e-10 0.189
nd
1.56883
Vd
55.98
glass code
569560.305
glass status
standard
density
value: 3046
thermal expansion
value: 6.99e-06, temperature range: 243 343; value: 7.93e-06, temperature range: 293 573
dPgF
-0.001
resistance
acid: 1.2; stain: 0.0; alkali: 1.0; climatic: 1.0; phosphate: 1.0

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = 2.11e-06 K⁻¹ at 633 nm, dn/dT = 1.54e-06 K⁻¹ at 1310 nm, dn/dT = 1.49e-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 420 wavelengths, the same grid as the API and the library
N-BAK4HT (SCHOTT), N-BAK4HT: n and k versus wavelength
λ (µm)nk
0.3341.6029432.502500e-06
0.3356891.6023862.299361e-06
0.3373871.6018362.095194e-06
0.3390931.6012941.889995e-06
0.3408081.6007591.683758e-06
0.3425321.6002321.476478e-06
0.3442641.5997111.268150e-06
0.3460061.5991981.058768e-06
0.3477561.5986918.483266e-07
0.3495141.5981916.368212e-07
0.351.5980555.784300e-07
0.3512821.5976985.440813e-07
0.3530591.5972114.964848e-07
0.3548441.596734.486475e-07
0.3566391.5962564.005683e-07
0.3584431.5957883.522460e-07
0.3602561.5953263.036792e-07
0.3620781.5948692.548669e-07
0.3639091.5944192.058076e-07
0.3651.5941541.765800e-07
0.365751.5939741.687115e-07
0.3675991.5935351.492921e-07
0.3694591.5931021.297744e-07
0.371.5929771.240900e-07
0.3713271.5926741.160248e-07
0.3732051.5922511.046114e-07
0.3750931.5918349.314032e-08
0.376991.5914228.161122e-08
0.3788961.5910157.002381e-08
0.381.5907836.331700e-08
0.3808131.5906136.103631e-08
0.3827391.5902165.563155e-08
0.3846741.5898245.019946e-08
0.386621.5894374.473989e-08
0.3885751.5890553.925271e-08
0.391.588783.525500e-08
0.3905411.5886773.452921e-08
0.3925161.5883043.187769e-08
0.3945011.5879352.921276e-08
0.3964961.5875712.653435e-08
0.3985021.5872112.384240e-08
0.41.5869462.183100e-08
0.4005171.5868562.158827e-08
0.4025431.5865042.063742e-08
0.4045791.5861571.968177e-08
0.4051.5860861.948400e-08
0.4066251.5858141.868271e-08
0.4086811.5854751.766856e-08
0.4107481.5851411.664927e-08
0.4128261.584811.562483e-08
0.4149141.5844831.459521e-08
0.4170121.584161.356038e-08
0.4191211.583841.252032e-08
0.421.5837091.208700e-08
0.4212411.5835251.201409e-08
0.4233721.5832131.188892e-08
0.4255131.5829041.176312e-08
0.4276651.5825991.163669e-08
0.4298281.5822981.150962e-08
0.4320021.5821.138190e-08
0.4341871.5817061.125354e-08
0.4361.5814651.114700e-08
0.4363831.5814151.113327e-08
0.438591.5811271.105410e-08
0.4408081.5808431.097452e-08
0.4430371.5805611.089454e-08
0.4452781.5802831.081415e-08
0.447531.5800091.073336e-08
0.4497941.5797371.065216e-08
0.4520681.5794681.057055e-08
0.4543551.5792021.048852e-08
0.4566531.5789391.040608e-08
0.4589621.578681.032323e-08
0.461.5785641.028600e-08
0.4612841.5784231.021193e-08
0.4636171.5781681.007730e-08
0.4659611.5779179.941984e-09
0.4683181.5776699.805988e-09
0.4706871.5774239.669303e-09
0.4730671.577189.531927e-09
0.475461.5769399.393857e-09
0.4778641.5767019.255088e-09
0.4802811.5764669.115617e-09
0.482711.5762338.975441e-09
0.4851521.5760038.834556e-09
0.4876051.5757758.692958e-09
0.4900721.575558.550644e-09
0.492551.5753278.407610e-09
0.4950411.5751068.263853e-09
0.4975451.5748888.119369e-09
0.51.5746787.977700e-09
0.5000611.5746727.976348e-09
0.5025911.5744597.920713e-09
0.5051321.5742487.864797e-09
0.5076871.5740397.808597e-09
0.5102551.5738327.752114e-09
0.5128361.5736277.695344e-09
0.5154291.5734247.638288e-09
0.5180361.5732247.580943e-09
0.5206561.5730257.523308e-09
0.5232891.5728297.465382e-09
0.5259361.5726357.407162e-09
0.5285961.5724437.348648e-09
0.531271.5722527.289838e-09
0.5339561.5720647.230731e-09
0.5366571.5718777.171325e-09
0.5393711.5716937.111618e-09
0.5420991.571517.051610e-09
0.5448411.5713296.991297e-09
0.5461.5712546.965800e-09
0.5475971.571156.986170e-09
0.5503661.5709737.021506e-09
0.553151.5707977.057020e-09
0.5559471.5706247.092715e-09
0.5587591.5704527.128590e-09
0.5615851.5702817.164646e-09
0.5644251.5701137.200885e-09
0.567281.5699467.237307e-09
0.5701491.5697817.273913e-09
0.5730331.5696177.310704e-09
0.5759311.5694557.347681e-09
0.5788441.5692947.384846e-09
0.581.5692317.399600e-09
0.5817711.5691357.422196e-09
0.5847141.5689787.459733e-09
0.5876711.5688227.497460e-09
0.5906431.5686677.535379e-09
0.593631.5685147.573488e-09
0.5966331.5683637.611791e-09
0.599651.5682137.650287e-09
0.6026831.5680647.688978e-09
0.6057311.5679177.727865e-09
0.6087951.5677717.766948e-09
0.6118741.5676267.806229e-09
0.6149681.5674837.845709e-09
0.6180791.5673417.885388e-09
0.621.5672547.909900e-09
0.6212051.56727.925268e-09
0.6243461.5670617.965350e-09
0.6275041.5669238.005635e-09
0.6306781.5667868.046123e-09
0.6338681.5666518.086816e-09
0.6370731.5665168.127715e-09
0.6402961.5663838.168820e-09
0.6435341.5662518.210134e-09
0.6467891.566128.251656e-09
0.650061.5659918.293389e-09
0.6533481.5658628.335332e-09
0.6566521.5657358.377488e-09
0.6599731.5656098.419857e-09
0.661.5656088.420200e-09
0.6633111.5654838.462440e-09
0.6666661.5653598.505239e-09
0.6700381.5652368.548254e-09
0.6734261.5651148.591486e-09
0.6768321.5649938.634937e-09
0.6802551.5648738.678608e-09
0.6836961.5647548.722500e-09
0.6871541.5646368.766614e-09
0.6906291.5645198.810951e-09
0.6941221.5644038.855512e-09
0.6976331.5642888.900299e-09
0.71.5642118.930500e-09
0.7011611.5641748.923483e-09
0.7047071.564068.902053e-09
0.7082711.5639488.880513e-09
0.7118541.5638368.858865e-09
0.7154541.5637268.837107e-09
0.7190721.5636168.815240e-09
0.7227091.5635078.793261e-09
0.7263641.5633998.771172e-09
0.7300381.5632928.748970e-09
0.733731.5631858.726657e-09
0.7374411.563088.704230e-09
0.7411711.5629758.681691e-09
0.7449191.5628718.659037e-09
0.7486871.5627678.636268e-09
0.7524741.5626658.613385e-09
0.7562791.5625638.590386e-09
0.7601041.5624628.567270e-09
0.7639491.5623628.544038e-09
0.7678121.5622628.520688e-09
0.7716961.5621638.497219e-09
0.7755991.5620658.473633e-09
0.7795211.5619678.449927e-09
0.7834641.561878.426101e-09
0.7874261.5617748.402154e-09
0.7914091.5616788.378087e-09
0.7954111.5615838.353897e-09
0.7994341.5614888.329586e-09
0.8034781.5613948.305151e-09
0.8075411.5613018.280593e-09
0.8116251.5612098.255910e-09
0.815731.5611168.231103e-09
0.8198561.5610258.206170e-09
0.8240031.5609348.181112e-09
0.828171.5608438.155926e-09
0.8323591.5607538.130613e-09
0.8365681.5606648.105172e-09
0.8407991.5605758.079602e-09
0.8450521.5604878.053904e-09
0.8493261.5603998.028075e-09
0.8536211.5603118.002115e-09
0.8579391.5602247.976024e-09
0.8622781.5601387.949801e-09
0.8666391.5600527.923446e-09
0.8710221.5599667.896957e-09
0.8754271.5598817.870335e-09
0.8798551.5597967.843577e-09
0.8843051.5597127.816685e-09
0.8887771.5596287.789656e-09
0.8932721.5595457.762491e-09
0.897791.5594617.735188e-09
0.9023311.5593797.707747e-09
0.9068951.5592967.680167e-09
0.9114811.5592147.652448e-09
0.9160911.5591327.624589e-09
0.9207241.5590517.596589e-09
0.9253811.558977.568447e-09
0.9300611.5588897.540163e-09
0.9347651.5588097.511735e-09
0.9394931.5587297.483164e-09
0.9442451.5586497.454449e-09
0.949021.5585697.425588e-09
0.953821.558497.396581e-09
0.9586441.5584117.367428e-09
0.9634921.5583327.338127e-09
0.9683651.5582547.308678e-09
0.9732631.5581767.279080e-09
0.9781851.5580987.249332e-09
0.9831331.558027.219434e-09
0.9881051.5579427.189385e-09
0.9931031.5578657.159184e-09
0.9981251.5577887.128829e-09
1.003171.5577117.098322e-09
1.008251.5576347.067660e-09
1.013351.5575587.036843e-09
1.018471.5574817.005870e-09
1.023621.5574056.974741e-09
1.02881.5573296.943454e-09
1.0341.5572536.912009e-09
1.039231.5571776.880404e-09
1.044491.5571016.848640e-09
1.049771.5570266.816716e-09
1.055081.556956.784630e-09
1.061.5568816.754900e-09
1.060421.5568756.787955e-09
1.065781.5567997.213302e-09
1.071171.5567247.640801e-09
1.076591.5566498.070462e-09
1.082031.5565748.502296e-09
1.087511.5564998.936314e-09
1.093011.5564249.372527e-09
1.098531.5563499.810946e-09
1.104091.5562741.025158e-08
1.109671.5561991.069445e-08
1.115291.5561241.113955e-08
1.120931.5560491.158691e-08
1.12661.5559751.203653e-08
1.132291.55591.248842e-08
1.138021.5558251.294260e-08
1.143781.555751.339907e-08
1.149561.5556751.385786e-08
1.155371.55561.431896e-08
1.161221.5555251.478240e-08
1.167091.555451.524818e-08
1.172991.5553751.571632e-08
1.178931.55531.618682e-08
1.184891.5552241.665970e-08
1.190881.5551491.713498e-08
1.19691.5550731.761266e-08
1.202961.5549981.809275e-08
1.209041.5549221.857527e-08
1.215161.5548461.906024e-08
1.22131.554771.954765e-08
1.227481.5546942.003754e-08
1.233691.5546182.052989e-08
1.239931.5545412.102474e-08
1.24621.5544652.152210e-08
1.25251.5543882.202196e-08
1.258841.5543112.252436e-08
1.26521.5542342.302929e-08
1.27161.5541572.353678e-08
1.278031.5540792.404684e-08
1.28451.5540022.455948e-08
1.290991.5539242.507471e-08
1.297521.5538452.559254e-08
1.304091.5537672.611300e-08
1.310681.5536882.663608e-08
1.317311.5536092.716181e-08
1.323971.553532.769020e-08
1.330671.5534512.822127e-08
1.33741.5533712.875502e-08
1.344161.5532912.929146e-08
1.350961.553212.983063e-08
1.357791.553133.037252e-08
1.364661.5530493.091714e-08
1.371561.5529673.146453e-08
1.37851.5528863.201468e-08
1.385471.5528043.256762e-08
1.392481.5527213.312335e-08
1.399521.5526393.368189e-08
1.40661.5525563.424326e-08
1.413711.5524723.480746e-08
1.420861.5523883.537452e-08
1.428051.5523043.594445e-08
1.435271.5522193.651726e-08
1.442531.5521343.709297e-08
1.449831.5520483.767158e-08
1.457161.5519623.825313e-08
1.464531.5518763.883762e-08
1.471941.5517893.942506e-08
1.479381.5517024.001547e-08
1.486861.5516144.060887e-08
1.494381.5515254.120527e-08
1.501941.5514374.180469e-08
1.509541.5513474.240714e-08
1.517171.5512574.301263e-08
1.524851.5511674.362119e-08
1.531.5511064.403000e-08
1.532561.5510764.568200e-08
1.540311.5509845.068886e-08
1.54811.5508925.572104e-08
1.555931.55086.077867e-08
1.56381.5507066.586187e-08
1.571711.5506127.097079e-08
1.579661.5505187.610555e-08
1.587651.5504238.126628e-08
1.595681.5503278.645310e-08
1.603751.5502319.166616e-08
1.611861.5501349.690559e-08
1.620011.5500361.021715e-07
1.62821.5499381.074641e-07
1.636441.5498391.127834e-07
1.644711.5497391.181296e-07
1.653031.5496391.235029e-07
1.661391.5495381.289033e-07
1.669791.5494361.343311e-07
1.678241.5493331.397863e-07
1.686731.549231.452691e-07
1.695261.5491261.507796e-07
1.703831.5490211.563180e-07
1.712451.5489151.618844e-07
1.721111.5488091.674790e-07
1.729821.5487011.731019e-07
1.738561.5485931.787532e-07
1.747361.5484841.844330e-07
1.756191.5483741.901416e-07
1.765081.5482631.958791e-07
1.7741.5481522.016456e-07
1.782981.5480392.074413e-07
1.791991.5479262.132663e-07
1.801061.5478112.191207e-07
1.810171.5476962.250047e-07
1.819321.547582.309185e-07
1.828521.5474632.368622e-07
1.837771.5473452.428360e-07
1.847071.5472252.488400e-07
1.856411.5471052.548744e-07
1.86581.5469842.609392e-07
1.875231.5468622.670348e-07
1.884721.5467382.731611e-07
1.894251.5466142.793185e-07
1.903831.5464892.855070e-07
1.913461.5463622.917268e-07
1.923141.5462342.979781e-07
1.932861.5461053.042609e-07
1.942641.5459753.105756e-07
1.952461.5458443.169222e-07
1.962341.5457123.233009e-07
1.971.5456093.282500e-07
1.972261.5455793.360408e-07
1.982241.5454443.703814e-07
1.992261.5453084.048956e-07
2.002341.5451714.395844e-07
2.012471.5450324.744486e-07
2.022641.5448925.094892e-07
2.032871.5447515.447070e-07
2.043161.5446095.801029e-07
2.053491.5444656.156778e-07
2.063881.544326.514327e-07
2.074311.5441746.873684e-07
2.08481.5440267.234858e-07
2.095351.5438777.597859e-07
2.105951.5437267.962696e-07
2.11661.5435748.329378e-07
2.12731.543428.697915e-07
2.138061.5432659.068316e-07
2.148881.5431089.440590e-07
2.159741.542959.814747e-07
2.170671.5427911.019080e-06
2.181641.5426291.056875e-06
2.192681.5424661.094861e-06
2.203771.5423021.133039e-06
2.214911.5421361.171411e-06
2.226121.5419681.209976e-06
2.237381.5417981.248737e-06
2.248691.5416271.287694e-06
2.260061.5414541.326847e-06
2.271491.541281.366199e-06
2.282981.5411031.405750e-06
2.294531.5409251.445500e-06
2.306131.5407451.485452e-06
2.31781.5405631.525606e-06
2.3251.540451.550400e-06
2.329521.5403791.591754e-06
2.34131.5401931.699534e-06
2.353141.5400061.807860e-06
2.365051.5398161.916733e-06
2.377011.5396242.026157e-06
2.389031.5394312.136134e-06
2.401111.5392352.246668e-06
2.413261.5390372.357760e-06
2.425461.5388382.469414e-06
2.437731.5386362.581634e-06
2.450061.5384312.694420e-06
2.462451.5382252.807777e-06
2.47491.5380172.921708e-06
2.487421.5378063.036214e-06
2.51.5375933.151300e-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
—