Optical constants

Refractive index of J-BK7A (HIKARI)

J-BK7A: n,k 0.365–2.058 µm

Data
formula 3 + tabulated k
Range
0.365–2.058 µm
Temperature
296 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.365–2.058 µm
Refractive index n
1.5168
Extinction coefficient k
1.87414e-08
Permittivity ε1
2.30068
Permittivity ε2
5.68540e-08
Absorption coefficient α
0.00400803 cm⁻¹
Penetration depth δ = λ/(2πk)
4.98998e+09 nm
Abbe number Vd
64.13
Chromatic dispersion dn/dλ
-0.0417995 µm⁻¹
Group index ng
1.54136
Group velocity dispersion
70.675 fs²/mm
Dispersion parameter D
-385.569 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

# J-BK7A (HIKARI): J-BK7A
hikari_j_bk7a = ls.fetch_refractiveindex("specs", "HIKARI-optical", "J-BK7A", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(hikari_j_bk7a.range_nm)  # (365.015, 2058.09) nm
eps = hikari_j_bk7a.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

Polynomial (formula 3), λ in µm
n2=2.27110883−0.00938988354⁢λ2.0−0.000100277081⁢λ4.0+0.0109572221⁢λ−2.0+0.000120210067⁢λ−4.0+3.31079774×10-6⁢λ−6.0−1.48235581×10-8⁢λ−8.0

Valid from 0.365015 to 2.05809 µm.

Coefficients as stored
CiValue
C12.27110883
C2-0.00938988354
C32.0
C4-0.000100277081
C54.0
C60.0109572221
C7-2.0
C80.000120210067
C9-4.0
C103.31079774e-06
C11-6.0
C12-1.48235581e-08
C13-8.0

Comments and conditions

Conditions

temperature
296 K

Properties

thermal dispersion
type: formula A, coefficients: 8.20811e-07 8.68946e-09 -1.28363e-13 5.04167e-07 5.18196e-10 0.147522
nd
1.516800
Vd
64.129950
density
value: 2510
thermal expansion
value: 7.4e-06, temperature range: 243 343
dPgF
-0.001
resistance
phosphate: 1.0

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 296.0 K): dn/dT = 9.20e-07 K⁻¹ at 633 nm, dn/dT = 4.69e-07 K⁻¹ at 1310 nm, dn/dT = 4.31e-07 K⁻¹ at 1550 nm

References

Cite

NIKON Zemax catalog 2017-11 (obtained from http://www.nikon.com); See also HIKARI 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 421 wavelengths, the same grid as the API and the library
J-BK7A (HIKARI), J-BK7A: n and k versus wavelength
λ (µm)nk
0.3650151.5363013.504958e-08
0.3666011.5360173.331354e-08
0.3681931.5357363.156996e-08
0.3697931.5354582.981881e-08
0.371.5354222.959200e-08
0.3713991.5351832.970394e-08
0.3730131.534912.983302e-08
0.3746331.5346412.996266e-08
0.3762611.5343733.009286e-08
0.3778951.5341093.022362e-08
0.3795371.5338473.035495e-08
0.381.5337743.039200e-08
0.3811861.5335882.863299e-08
0.3828421.5333312.617637e-08
0.3845051.5330772.370909e-08
0.3861751.5328252.123108e-08
0.3878531.5325761.874231e-08
0.3895381.5323291.624272e-08
0.391.5322621.555700e-08
0.391231.5320851.521272e-08
0.392931.5318431.473700e-08
0.3946371.5316031.425922e-08
0.3963511.5313661.377936e-08
0.3980731.5311311.329742e-08
0.3998021.5308981.281338e-08
0.41.5308721.275800e-08
0.4015391.5306681.280709e-08
0.4032831.5304391.286274e-08
0.4050351.5302131.291863e-08
0.4067951.5299891.297476e-08
0.4085621.5297671.303113e-08
0.4103371.5295481.308775e-08
0.412121.529331.314461e-08
0.413911.5291141.320173e-08
0.4157081.5289011.325909e-08
0.4175141.528691.331670e-08
0.4193281.528481.337456e-08
0.421.5284031.339600e-08
0.4211491.5282731.363479e-08
0.4229791.5280671.401488e-08
0.4248171.5278631.439663e-08
0.4266621.5276621.478003e-08
0.4285161.5274621.516510e-08
0.4303771.5272641.555184e-08
0.4322471.5270681.594026e-08
0.4341251.5268731.633037e-08
0.436011.5266811.672218e-08
0.4379051.526491.711568e-08
0.4398071.5263011.751090e-08
0.441.5262821.755100e-08
0.4417181.5261141.761953e-08
0.4436371.5259291.769610e-08
0.4455641.5257451.777299e-08
0.4474991.5255631.785023e-08
0.4494431.5253821.792779e-08
0.4513961.5252031.800570e-08
0.4533571.5250261.808394e-08
0.4553261.5248511.816252e-08
0.4573041.5246771.824145e-08
0.4592911.5245041.832071e-08
0.461.5244431.834900e-08
0.4612861.5243331.815354e-08
0.463291.5241641.784904e-08
0.4653031.5239961.754322e-08
0.4673241.523831.723607e-08
0.4693541.5236651.692759e-08
0.4713931.5235021.661776e-08
0.4734411.523341.630659e-08
0.4754981.5231791.599407e-08
0.4775641.523021.568019e-08
0.4796381.5228631.536495e-08
0.481.5228351.531000e-08
0.4817221.5227061.536485e-08
0.4838151.5225511.543150e-08
0.4859171.5223981.549844e-08
0.4880271.5222461.556568e-08
0.4901481.5220951.563320e-08
0.4922771.5219451.570102e-08
0.4944151.5217971.576913e-08
0.4965631.521651.583754e-08
0.4987211.5215041.590625e-08
0.51.5214191.594700e-08
0.5008871.521361.597530e-08
0.5030631.5212171.604471e-08
0.5052481.5210751.611443e-08
0.5074431.5209341.618444e-08
0.5096481.5207941.625477e-08
0.5118621.5206561.632539e-08
0.5140861.5205191.639633e-08
0.5163191.5203831.646757e-08
0.5185621.5202481.653912e-08
0.5208151.5201141.661099e-08
0.5230771.5199821.668316e-08
0.5253491.519851.675565e-08
0.5276321.519721.682845e-08
0.5299241.519591.690157e-08
0.5322261.5194621.697501e-08
0.5345381.5193351.704877e-08
0.536861.5192081.712284e-08
0.5391931.5190831.719724e-08
0.5415351.5189591.727196e-08
0.5438871.5188361.734701e-08
0.546251.5187141.742238e-08
0.5486231.5185931.749808e-08
0.551.5185231.754200e-08
0.5510071.5184731.757411e-08
0.55341.5183541.765047e-08
0.5558041.5182351.772716e-08
0.5582191.5181181.780419e-08
0.5606441.5180021.788154e-08
0.563081.5178861.795924e-08
0.5655261.5177721.803727e-08
0.5679821.5176581.811564e-08
0.570451.5175451.819435e-08
0.5729281.5174341.827341e-08
0.5754171.5173231.835280e-08
0.5779171.5172131.843255e-08
0.5804271.5171031.851263e-08
0.5829491.5169951.859307e-08
0.5854811.5168871.867386e-08
0.5880251.5167811.875499e-08
0.5905791.5166751.883648e-08
0.5931451.516571.891832e-08
0.5957221.5164651.900052e-08
0.598311.5163621.908308e-08
0.61.5162951.913700e-08
0.6009091.5162591.935499e-08
0.6035191.5161571.998109e-08
0.6061411.5160562.060991e-08
0.6087741.5159552.124146e-08
0.6114191.5158552.187575e-08
0.6140751.5157562.251280e-08
0.6167431.5156582.315262e-08
0.6194221.5155612.379522e-08
0.6221131.5154642.444061e-08
0.6248161.5153672.508880e-08
0.627531.5152722.573981e-08
0.6302561.5151772.639365e-08
0.6329941.5150832.705032e-08
0.6357441.514992.770985e-08
0.6385061.5148972.837225e-08
0.641281.5148042.903752e-08
0.6440661.5147132.970569e-08
0.6468641.5146223.037675e-08
0.6496741.5145323.105073e-08
0.651.5145213.112900e-08
0.6524961.5144423.152841e-08
0.6553311.5143533.198200e-08
0.6581781.5142653.243756e-08
0.6610371.5141773.289511e-08
0.6639081.5140893.335463e-08
0.6667931.5140033.381616e-08
0.6696891.5139163.427969e-08
0.6725991.5138313.474523e-08
0.6755211.5137463.521280e-08
0.6784551.5136613.568240e-08
0.6814031.5135773.615404e-08
0.6843631.5134943.662772e-08
0.6873361.5134113.710347e-08
0.6903221.5133293.758128e-08
0.6933211.5132473.806117e-08
0.6963331.5131663.854314e-08
0.6993581.5130853.902720e-08
0.71.5130683.913000e-08
0.7023961.5130043.987954e-08
0.7054471.5129254.083420e-08
0.7085121.5128454.179299e-08
0.711591.5127664.275596e-08
0.7146811.5126884.372311e-08
0.7177861.512614.469446e-08
0.7209041.5125324.567003e-08
0.7240361.5124554.664983e-08
0.7271811.5123794.763390e-08
0.730341.5123024.862224e-08
0.7335131.5122274.961487e-08
0.73671.5121515.061181e-08
0.73991.5120765.161309e-08
0.7431141.5120025.261871e-08
0.7463421.5119275.362871e-08
0.7495851.5118545.464309e-08
0.7528411.511785.566188e-08
0.7561121.5117075.668509e-08
0.7593961.5116355.771275e-08
0.7626951.5115625.874488e-08
0.7660091.5114915.978148e-08
0.7693361.5114196.082259e-08
0.7726791.5113486.186823e-08
0.7760351.5112776.291840e-08
0.7794071.5112076.397314e-08
0.7827931.5111366.503246e-08
0.7861931.5110676.609638e-08
0.7896091.5109976.716493e-08
0.7930391.5109286.823812e-08
0.7964841.5108596.931596e-08
0.7999441.5107917.039849e-08
0.81.510797.041600e-08
0.8034191.5107226.874408e-08
0.8069091.5106546.703743e-08
0.8104151.5105876.532335e-08
0.8139351.5105196.360184e-08
0.8174711.5104526.187284e-08
0.8210231.5103856.013633e-08
0.8245891.5103195.839228e-08
0.8281721.5102535.664065e-08
0.8317691.5101875.488141e-08
0.8353831.5101215.311453e-08
0.8390121.5100555.133997e-08
0.8426571.509994.955771e-08
0.8463171.5099254.776770e-08
0.8499941.509864.596992e-08
0.8536871.5097954.416432e-08
0.8573951.5097314.235088e-08
0.861121.5096674.052957e-08
0.8648611.5096033.870034e-08
0.8686181.5095393.686316e-08
0.8723911.5094763.501801e-08
0.8761811.5094123.316483e-08
0.8799881.5093493.130361e-08
0.8838111.5092862.943430e-08
0.887651.5092232.755687e-08
0.8915061.5091612.567129e-08
0.8953791.5090982.377751e-08
0.8992691.5090362.187551e-08
0.91.5090242.151800e-08
0.9031751.5089742.184752e-08
0.9070991.5089122.225467e-08
0.911041.508852.266360e-08
0.9149981.5087882.307429e-08
0.9189721.5087272.348678e-08
0.9229651.5086652.390105e-08
0.9269741.5086042.431712e-08
0.9310011.5085432.473500e-08
0.9350461.5084822.515470e-08
0.9391081.5084212.557622e-08
0.9431881.508362.599957e-08
0.9472851.5082992.642476e-08
0.95141.5082392.685180e-08
0.9555331.5081782.728069e-08
0.9596841.5081182.771145e-08
0.9638531.5080572.814407e-08
0.9680411.5079972.857858e-08
0.9722461.5079372.901497e-08
0.976471.5078772.945326e-08
0.9807121.5078172.989346e-08
0.9849721.5077573.033556e-08
0.9892511.5076973.077959e-08
0.9935491.5076373.122554e-08
0.9978651.5075773.167344e-08
11.5075473.189500e-08
1.00221.5075173.185976e-08
1.006551.5074573.179001e-08
1.010931.5073983.171996e-08
1.015321.5073383.164961e-08
1.019731.5072783.157894e-08
1.024161.5072193.150798e-08
1.028611.5071593.143670e-08
1.033081.5070993.136512e-08
1.037561.507043.129322e-08
1.042071.506983.122101e-08
1.04661.506923.114849e-08
1.051151.5068613.107565e-08
1.055711.5068013.100250e-08
1.06031.5067413.092902e-08
1.06491.5066823.085523e-08
1.069531.5066223.078112e-08
1.074181.5065623.070669e-08
1.078841.5065023.063193e-08
1.083531.5064423.055685e-08
1.088241.5063823.048144e-08
1.092961.5063233.040571e-08
1.097711.5062623.032964e-08
1.102481.5062023.025325e-08
1.107271.5061423.017652e-08
1.112081.5060823.009946e-08
1.116911.5060223.002206e-08
1.121761.5059612.994433e-08
1.126641.5059012.986626e-08
1.131531.505842.978786e-08
1.136451.505782.970911e-08
1.141381.5057192.963002e-08
1.146341.5056582.955058e-08
1.151321.5055972.947080e-08
1.156321.5055362.939068e-08
1.161351.5054752.931020e-08
1.166391.5054132.922938e-08
1.171461.5053522.914821e-08
1.176551.505292.906668e-08
1.181661.5052282.898480e-08
1.186791.5051662.890256e-08
1.191951.5051042.881997e-08
1.197131.5050422.873701e-08
1.21.5050082.869100e-08
1.202331.504983.137501e-08
1.207551.5049173.739576e-08
1.21281.5048544.344267e-08
1.218071.5047914.951584e-08
1.223361.5047285.561540e-08
1.228671.5046656.174146e-08
1.234011.5046026.789413e-08
1.239371.5045387.407353e-08
1.244751.5044748.027978e-08
1.250161.504418.651298e-08
1.255591.5043469.277327e-08
1.261051.5042819.906075e-08
1.266531.5042161.053755e-07
1.272031.5041511.117178e-07
1.277551.5040861.180875e-07
1.28311.5040211.244850e-07
1.288681.5039551.309102e-07
1.294281.5038891.373634e-07
1.29991.5038231.438446e-07
1.305551.5037561.503539e-07
1.311221.503691.568916e-07
1.316911.5036231.634576e-07
1.322641.5035551.700521e-07
1.328381.5034881.766753e-07
1.334151.503421.833273e-07
1.339951.5033521.900082e-07
1.345771.5032831.967181e-07
1.351621.5032152.034571e-07
1.357491.5031462.102254e-07
1.363381.5030762.170231e-07
1.369311.5030072.238504e-07
1.375261.5029372.307073e-07
1.381231.5028662.375940e-07
1.387231.5027952.445106e-07
1.393261.5027242.514573e-07
1.399311.5026532.584341e-07
1.41.5026452.592300e-07
1.405391.5025812.567346e-07
1.411491.5025092.539072e-07
1.417631.5024372.510675e-07
1.423781.5023642.482155e-07
1.429971.502292.453512e-07
1.436181.5022172.424743e-07
1.442421.5021432.395850e-07
1.448691.5020682.366831e-07
1.454981.5019932.337686e-07
1.46131.5019182.308415e-07
1.467651.5018432.279016e-07
1.474031.5017662.249490e-07
1.480431.501692.219835e-07
1.486861.5016132.190052e-07
1.493321.5015352.160139e-07
1.499811.5014582.130096e-07
1.506321.5013792.099922e-07
1.512871.50132.069618e-07
1.519441.5012212.039182e-07
1.526041.5011412.008614e-07
1.532671.5010611.977913e-07
1.539331.500981.947078e-07
1.546011.5008991.916110e-07
1.552731.5008171.885007e-07
1.559481.5007351.853769e-07
1.566251.5006521.822395e-07
1.573051.5005691.790885e-07
1.579891.5004851.759238e-07
1.586751.5004011.727454e-07
1.593641.5003161.695531e-07
1.61.5002371.666100e-07
1.600571.500231.677973e-07
1.607521.5001441.823337e-07
1.61451.5000581.969333e-07
1.621521.499972.115964e-07
1.628561.4998832.263231e-07
1.635641.4997942.411138e-07
1.642741.4997052.559687e-07
1.649881.4996162.708882e-07
1.657051.4995252.858725e-07
1.664251.4994353.009219e-07
1.671481.4993433.160367e-07
1.678741.4992513.312171e-07
1.686031.4991583.464635e-07
1.693351.4990653.617761e-07
1.700711.4989713.771552e-07
1.70811.4988763.926012e-07
1.715521.498784.081142e-07
1.722971.4986844.236947e-07
1.730461.4985884.393428e-07
1.737971.498494.550589e-07
1.745521.4983924.708433e-07
1.753111.4982934.866962e-07
1.760721.4981935.026180e-07
1.768371.4980925.186090e-07
1.776051.4979915.346695e-07
1.783771.4978895.507997e-07
1.791521.4977865.670000e-07
1.79931.4976835.832707e-07
1.81.4976745.847300e-07
1.807121.4975796.105372e-07
1.814971.4974736.389982e-07
1.822851.4973686.675828e-07
1.830771.4972616.962916e-07
1.838731.4971537.251251e-07
1.846711.4970457.540839e-07
1.854741.4969367.831685e-07
1.862791.4968258.123794e-07
1.870891.4967148.417172e-07
1.879011.4966038.711825e-07
1.887181.496499.007758e-07
1.895371.4963769.304976e-07
1.903611.4962629.603486e-07
1.911881.4961469.903292e-07
1.920181.496031.020440e-06
1.928531.4959121.050682e-06
1.93691.4957941.081055e-06
1.945321.4956751.111560e-06
1.953771.4955551.142197e-06
1.962261.4954331.172968e-06
1.970781.4953111.203872e-06
1.979341.4951881.234911e-06
1.987941.4950641.266084e-06
1.996581.4949381.297393e-06
21.4948891.309800e-06
2.005251.4948121.372273e-06
2.013961.4946851.475907e-06
2.022711.4945561.579990e-06
2.03151.4944271.684527e-06
2.040321.4942961.789517e-06
2.049191.4941641.894963e-06
2.058091.4940322.000868e-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
—