Optical constants

Refractive index of N-BK7 (SCHOTT)

N-BK7: 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
1.5168
Extinction coefficient k
9.75245e-09
Permittivity ε1
2.30068
Permittivity ε2
2.95850e-08
Absorption coefficient α
0.00208565 cm⁻¹
Penetration depth δ = λ/(2πk)
9.58933e+09 nm
Abbe number Vd
64.167
Chromatic dispersion dn/dλ
-0.041792 µm⁻¹
Group index ng
1.54136
Group velocity dispersion
70.3722 fs²/mm
Dispersion parameter D
-383.918 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-BK7 (SCHOTT): N-BK7
schott_n_bk7 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-BK7", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_bk7.range_nm)  # (300, 2500) nm
eps = schott_n_bk7.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=1.03961212λ2λ2−0.00600069867+0.231792344λ2λ2−0.0200179144+1.01046945λ2λ2−103.560653

Valid from 0.3 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.03961212
C30.00600069867
C40.231792344
C50.0200179144
C61.01046945
C7103.560653

Comments and conditions

step 0.5 available

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 1.86e-06 1.31e-08 -1.37e-11 4.34e-07 6.27e-10 0.17
nd
1.5168
Vd
64.17
glass code
517642.251
glass status
standard
density
value: 2510
thermal expansion
value: 7.1e-06, temperature range: 243 343; value: 8.3e-06, temperature range: 293 573
dPgF
-0.0009
resistance
acid: 1.0; stain: 0.0; alkali: 2.3; climatic: 1.0; phosphate: 2.3

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = 1.29e-06 K⁻¹ at 633 nm, dn/dT = 8.88e-07 K⁻¹ at 1310 nm, dn/dT = 8.52e-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-BK7 (SCHOTT), N-BK7: n and k versus wavelength
λ (µm)nk
0.31.552772.860700e-06
0.3015981.5522072.622087e-06
0.3032051.5516522.382202e-06
0.3048211.5511042.141040e-06
0.3064451.5505641.898592e-06
0.3080781.5500311.654853e-06
0.3097191.5495061.409815e-06
0.311.5494171.367900e-06
0.3113691.5489871.271791e-06
0.3130281.5484761.155359e-06
0.3146961.5479711.038306e-06
0.3163731.5474749.206298e-07
0.3180591.5469838.023266e-07
0.3197531.5464986.833930e-07
0.321.5464296.660800e-07
0.3214571.546026.242510e-07
0.323171.5455495.750791e-07
0.3248921.5450835.256453e-07
0.3266231.5446244.759480e-07
0.3283631.5441714.259860e-07
0.3301121.5437243.757578e-07
0.3318711.5432823.252619e-07
0.333641.5428472.744970e-07
0.3341.5427592.641500e-07
0.3354171.5424172.489804e-07
0.3372041.5419922.298518e-07
0.3390011.5415732.106214e-07
0.3408071.541161.912884e-07
0.3426231.5407511.718524e-07
0.3444491.5403481.523129e-07
0.3462841.539951.326693e-07
0.3481291.5395581.129210e-07
0.3499841.539179.306749e-08
0.351.5391669.289400e-08
0.3518491.5387878.565970e-08
0.3537231.5384087.832307e-08
0.3556081.5380357.094736e-08
0.3575031.5376666.353235e-08
0.3594071.5373025.607783e-08
0.3613221.5369434.858359e-08
0.3632481.5365874.104943e-08
0.3651.536273.419100e-08
0.3651831.5362373.394273e-08
0.3671291.535893.130199e-08
0.3690851.5355482.864718e-08
0.371.535392.740500e-08
0.3710511.535212.670433e-08
0.3730281.5348772.538667e-08
0.3750161.5345472.406198e-08
0.3770141.5342212.273024e-08
0.3790231.5338992.139140e-08
0.381.5337452.074000e-08
0.3810421.5335822.000957e-08
0.3830721.5332681.858659e-08
0.3851131.5329571.715602e-08
0.3871651.5326511.571783e-08
0.3892281.5323481.427198e-08
0.391.5322361.373100e-08
0.3913021.5320491.327478e-08
0.3933871.5317531.254423e-08
0.3954831.5314611.180979e-08
0.397591.5311731.107144e-08
0.3997081.5308871.032916e-08
0.41.5308491.022700e-08
0.4018381.5306069.796433e-09
0.4039791.5303279.294919e-09
0.4051.5301969.055800e-09
0.4061321.5300529.081103e-09
0.4082961.529789.129488e-09
0.4104711.5295119.178130e-09
0.4126581.5292459.227032e-09
0.4148571.5289839.276195e-09
0.4170671.5287239.325619e-09
0.4192891.5284669.375307e-09
0.421.5283859.391200e-09
0.4215231.5282139.558355e-09
0.4237691.5279629.804816e-09
0.4260271.5277141.005259e-08
0.4282971.5274691.030168e-08
0.4305791.5272271.055211e-08
0.4328731.5269881.080386e-08
0.4351791.5267511.105696e-08
0.4361.5266681.114700e-08
0.4374981.5265171.109325e-08
0.4398291.5262861.100963e-08
0.4421731.5260571.092556e-08
0.4445291.5258311.084104e-08
0.4468971.5256071.075607e-08
0.4492781.5253861.067065e-08
0.4516721.5251671.058477e-08
0.4540781.5249511.049843e-08
0.4564981.5247371.041164e-08
0.458931.5245251.032438e-08
0.461.5244331.028600e-08
0.4613751.5243161.026166e-08
0.4638341.5241091.021815e-08
0.4663051.5239051.017442e-08
0.4687891.5237021.013045e-08
0.4712871.5235021.008624e-08
0.4737981.5233041.004181e-08
0.4763231.5231089.997129e-09
0.4788611.5229159.952215e-09
0.4814121.5227239.907061e-09
0.4839771.5225339.861667e-09
0.4865561.5223469.816031e-09
0.4891481.522169.770152e-09
0.4917541.5219779.724028e-09
0.4943741.5217959.677659e-09
0.4970081.5216159.631042e-09
0.4996571.5214379.584177e-09
0.51.5214149.578100e-09
0.5023191.5212619.446416e-09
0.5049951.5210879.294426e-09
0.5076861.5209159.141626e-09
0.5103911.5207448.988012e-09
0.513111.5205768.833579e-09
0.5158441.5204098.678323e-09
0.5185931.5202438.522240e-09
0.5213561.520088.365326e-09
0.5241341.5199188.207575e-09
0.5269261.5197588.048984e-09
0.5297341.5195997.889548e-09
0.5325561.5194427.729263e-09
0.5353941.5192867.568123e-09
0.5382461.5191327.406125e-09
0.5411141.518987.243264e-09
0.5439971.5188297.079535e-09
0.5461.5187266.965800e-09
0.5468961.518687.026083e-09
0.549811.5185327.222198e-09
0.5527391.5183867.419358e-09
0.5556841.5182417.617568e-09
0.5586451.5180977.816834e-09
0.5616211.5179558.017161e-09
0.5646141.5178148.218557e-09
0.5676221.5176748.421025e-09
0.5706461.5175368.624572e-09
0.5736871.51748.829203e-09
0.5767431.5172649.034925e-09
0.5798161.517139.241743e-09
0.581.5171229.254100e-09
0.5829061.5169979.444635e-09
0.5860111.5168659.648288e-09
0.5891341.5167359.853026e-09
0.5922731.5166051.005886e-08
0.5954281.5164771.026578e-08
0.5986011.516351.047381e-08
0.601791.5162241.068295e-08
0.6049971.51611.089320e-08
0.608221.5159761.110457e-08
0.6114611.5158541.131707e-08
0.6147191.5157331.153070e-08
0.6179941.5156121.174546e-08
0.621.5155391.187700e-08
0.6212871.5154931.190164e-08
0.6245971.5153751.196503e-08
0.6279251.5152581.202876e-08
0.6312711.5151421.209283e-08
0.6346341.5150271.215724e-08
0.6380151.5149121.222200e-08
0.6414151.5147991.228709e-08
0.6448321.5146871.235254e-08
0.6482681.5145761.241833e-08
0.6517221.5144651.248448e-08
0.6551951.5143561.255098e-08
0.6586851.5142471.261783e-08
0.661.5142071.264300e-08
0.6621951.514141.243928e-08
0.6657231.5140331.211181e-08
0.669271.5139271.178260e-08
0.6728361.5138221.145164e-08
0.6764211.5137181.111891e-08
0.6800251.5136141.078441e-08
0.6836481.5135111.044813e-08
0.6872911.513411.011006e-08
0.6909531.5133089.770185e-09
0.6946341.5132089.428500e-09
0.6983351.5131089.084994e-09
0.71.5130648.930500e-09
0.7020561.513018.937391e-09
0.7057971.5129118.949927e-09
0.7095571.5128148.962530e-09
0.7133381.5127178.975201e-09
0.7171391.5126218.987938e-09
0.720961.5125269.000744e-09
0.7248011.5124319.013618e-09
0.7286631.5123379.026560e-09
0.7325451.5122439.039572e-09
0.7364481.512159.052652e-09
0.7403721.5120589.065803e-09
0.7443171.5119679.079023e-09
0.7482831.5118769.092314e-09
0.752271.5117859.105676e-09
0.7562781.5116959.119109e-09
0.7603071.5116069.132613e-09
0.7643581.5115179.146189e-09
0.7684311.5114299.159838e-09
0.7725251.5113419.173560e-09
0.7766411.5112549.187354e-09
0.7807791.5111679.201222e-09
0.7849391.5110819.215164e-09
0.7891211.5109959.229181e-09
0.7933261.510919.243272e-09
0.7975531.5108259.257438e-09
0.8018021.5107419.271679e-09
0.8060741.5106579.285996e-09
0.8103691.5105739.300390e-09
0.8146871.510499.314860e-09
0.8190281.5104079.329408e-09
0.8233911.5103259.344033e-09
0.8277791.5102439.358736e-09
0.8321891.5101629.373517e-09
0.8366231.510089.388377e-09
0.8410811.519.403316e-09
0.8455621.5099199.418335e-09
0.8500671.5098399.433434e-09
0.8545961.5097599.448613e-09
0.859151.509689.463873e-09
0.8637271.50969.479214e-09
0.8683291.5095229.494638e-09
0.8729561.5094439.510143e-09
0.8776071.5093659.525731e-09
0.8822831.5092879.541402e-09
0.8869841.5092099.557156e-09
0.891711.5091319.572995e-09
0.8964611.5090549.588917e-09
0.9012381.5089779.604925e-09
0.9060391.50899.621018e-09
0.9108671.5088239.637197e-09
0.915721.5087479.653462e-09
0.9205991.5086719.669813e-09
0.9255041.5085959.686252e-09
0.9304351.5085199.702778e-09
0.9353931.5084439.719392e-09
0.9403771.5083689.736095e-09
0.9453871.5082929.752887e-09
0.9504241.5082179.769768e-09
0.9554881.5081429.786740e-09
0.9605791.5080679.803801e-09
0.9656971.5079929.820954e-09
0.9708421.5079179.838198e-09
0.9760151.5078439.855534e-09
0.9812151.5077689.872962e-09
0.9864431.5076939.890483e-09
0.9916991.5076199.908097e-09
0.9969831.5075449.925806e-09
1.00231.507479.943608e-09
1.007641.5073969.961506e-09
1.0131.5073229.979499e-09
1.01841.5072479.997587e-09
1.023831.5071731.001577e-08
1.029281.5070991.003405e-08
1.034771.5070251.005243e-08
1.040281.506951.007091e-08
1.045821.5068761.008949e-08
1.05141.5068021.010816e-08
1.0571.5067271.012694e-08
1.061.5066881.013700e-08
1.062631.5066531.063061e-08
1.068291.5065781.169373e-08
1.073981.5065041.276252e-08
1.07971.5064291.383701e-08
1.085461.5063551.491722e-08
1.091241.506281.600318e-08
1.097061.5062051.709493e-08
1.10291.506131.819250e-08
1.108781.5060551.929592e-08
1.114681.5059792.040521e-08
1.120621.5059042.152042e-08
1.126591.5058292.264157e-08
1.13261.5057532.376869e-08
1.138631.5056772.490181e-08
1.14471.5056012.604098e-08
1.15081.5055252.718621e-08
1.156931.5054482.833754e-08
1.163091.5053722.949501e-08
1.169291.5052953.065865e-08
1.175521.5052183.182849e-08
1.181781.505143.300456e-08
1.188081.5050633.418689e-08
1.194411.5049853.537553e-08
1.200771.5049073.657050e-08
1.207171.5048293.777183e-08
1.21361.504753.897957e-08
1.220071.5046714.019374e-08
1.226571.5045924.141438e-08
1.233111.5045134.264153e-08
1.239681.5044334.387521e-08
1.246281.5043534.511546e-08
1.252921.5042724.636233e-08
1.25961.5041914.761584e-08
1.266311.504114.887602e-08
1.273061.5040295.014292e-08
1.279841.5039475.141657e-08
1.286661.5038645.269701e-08
1.293511.5037825.398427e-08
1.30041.5036995.527839e-08
1.307331.5036155.657940e-08
1.31431.5035315.788734e-08
1.32131.5034475.920226e-08
1.328341.5033626.052418e-08
1.335421.5032776.185314e-08
1.342531.5031916.318918e-08
1.349691.5031046.453235e-08
1.356881.5030186.588266e-08
1.364111.502936.724018e-08
1.371381.5028436.860492e-08
1.378681.5027546.997694e-08
1.386031.5026667.135627e-08
1.393411.5025767.274295e-08
1.400841.5024867.413701e-08
1.40831.5023967.553851e-08
1.415811.5023057.694747e-08
1.423351.5022137.836393e-08
1.430931.5021217.978795e-08
1.438561.5020288.121955e-08
1.446221.5019348.265878e-08
1.453931.501848.410568e-08
1.461671.5017458.556028e-08
1.469461.501658.702264e-08
1.477291.5015548.849279e-08
1.485161.5014578.997077e-08
1.493081.501369.145663e-08
1.501031.5012619.295040e-08
1.509031.5011629.445214e-08
1.517071.5010639.596187e-08
1.525151.5009629.747965e-08
1.531.5009029.839000e-08
1.533281.5008611.058020e-07
1.541451.5007591.242744e-07
1.549661.5006561.428453e-07
1.557921.5005531.615150e-07
1.566221.5004481.802843e-07
1.574561.5003431.991535e-07
1.582951.5002372.181233e-07
1.591391.500132.371942e-07
1.599871.5000222.563666e-07
1.608391.4999142.756413e-07
1.616961.4998042.950186e-07
1.625571.4996943.144992e-07
1.634241.4995823.340835e-07
1.642941.499473.537722e-07
1.65171.4993573.735658e-07
1.66051.4992423.934649e-07
1.669341.4991274.134700e-07
1.678241.4990114.335817e-07
1.687181.4988944.538005e-07
1.696171.4987754.741271e-07
1.705211.4986564.945620e-07
1.714291.4985365.151057e-07
1.723431.4984145.357589e-07
1.732611.4982925.565222e-07
1.741841.4981685.773960e-07
1.751121.4980435.983811e-07
1.760451.4979176.194781e-07
1.769831.497796.406874e-07
1.779261.4976626.620097e-07
1.788741.4975326.834456e-07
1.798271.4974017.049957e-07
1.807851.4972697.266607e-07
1.817491.4971367.484411e-07
1.827171.4970027.703375e-07
1.83691.4968667.923506e-07
1.846691.4967298.144810e-07
1.856531.4965918.367293e-07
1.866421.4964518.590962e-07
1.876371.496318.815822e-07
1.886371.4961679.041880e-07
1.896421.4960239.269143e-07
1.906521.4958789.497617e-07
1.916681.4957319.727308e-07
1.926891.4955839.958222e-07
1.937161.4954331.019037e-06
1.947481.4952821.042375e-06
1.957851.4951291.065837e-06
1.968291.4949751.089425e-06
1.971.494951.093300e-06
1.978771.4948191.172331e-06
1.989321.4946621.267302e-06
1.999921.4945031.362778e-06
2.010571.4943421.458764e-06
2.021281.494181.555261e-06
2.032051.4940161.652272e-06
2.042881.493851.749800e-06
2.053771.4936831.847848e-06
2.064711.4935131.946418e-06
2.075711.4933422.045513e-06
2.086771.493172.145137e-06
2.097891.4929952.245291e-06
2.109061.4928182.345978e-06
2.12031.492642.447202e-06
2.13161.492462.548966e-06
2.142961.4922782.651272e-06
2.154371.4920932.754122e-06
2.165851.4919072.857521e-06
2.177391.4917192.961471e-06
2.188991.4915293.065974e-06
2.200661.4913373.171035e-06
2.212381.4911423.276655e-06
2.224171.4909463.382838e-06
2.236021.4907473.489587e-06
2.247931.4905463.596904e-06
2.259911.4903433.704793e-06
2.271951.4901383.813257e-06
2.284061.489933.922299e-06
2.296231.489724.031922e-06
2.308461.4895084.142129e-06
2.320761.4892934.252923e-06
2.3251.4892194.291100e-06
2.333131.4890764.469380e-06
2.345561.4888564.742076e-06
2.358061.4886345.016225e-06
2.370621.488415.291834e-06
2.383251.4881835.568912e-06
2.395951.4879535.847467e-06
2.408711.4877216.127505e-06
2.421551.4874866.409036e-06
2.434451.4872486.692066e-06
2.447421.4870086.976605e-06
2.460461.4867647.262659e-06
2.473571.4865187.550238e-06
2.486751.4862697.839349e-06
2.51.4860188.130000e-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
—