Optical constants

Refractive index of J-BAK4 (HIKARI)

J-BAK4: 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
1.56883
Extinction coefficient k
2.34385e-08
Permittivity ε1
2.46122
Permittivity ε2
7.35419e-08
Absorption coefficient α
0.00501254 cm⁻¹
Penetration depth δ = λ/(2πk)
3.98999e+09 nm
Abbe number Vd
56.001
Chromatic dispersion dn/dλ
-0.0523536 µm⁻¹
Group index ng
1.59959
Group velocity dispersion
92.7306 fs²/mm
Dispersion parameter D
-505.895 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-BAK4 (HIKARI): J-BAK4
hikari_j_bak4 = ls.fetch_refractiveindex("specs", "HIKARI-optical", "J-BAK4", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(hikari_j_bak4.range_nm)  # (365.015, 2058.09) nm
eps = hikari_j_bak4.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=2.42114503−0.00899959341⁢λ2.0−9.30006854×10-5⁢λ4.0+0.014307112⁢λ−2.0+0.000189993274⁢λ−4.0+6.09602388×10-6⁢λ−6.0+2.25737069×10-7⁢λ−8.0

Valid from 0.365015 to 2.05809 µm.

Coefficients as stored
CiValue
C12.42114503
C2-0.00899959341
C32.0
C4-9.30006854e-05
C54.0
C60.014307112
C7-2.0
C80.000189993274
C9-4.0
C106.09602388e-06
C11-6.0
C122.25737069e-07
C13-8.0

Comments and conditions

Conditions

temperature
296 K

Properties

thermal dispersion
type: formula A, coefficients: 1.7273e-06 1.4151e-08 -2.7892e-12 5.6282e-07 4.9115e-10 0.1856
nd
1.568830
Vd
56.000795
density
value: 2840
thermal expansion
value: 7e-06, temperature range: 243 343
dPgF
-0.002
resistance
phosphate: 2.0

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 296.0 K): dn/dT = 1.52e-06 K⁻¹ at 633 nm, dn/dT = 9.38e-07 K⁻¹ at 1310 nm, dn/dT = 8.90e-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-BAK4 (HIKARI), J-BAK4: n and k versus wavelength
λ (µm)nk
0.3650151.5941532.356534e-07
0.3666011.5937722.116965e-07
0.3681931.5933961.876355e-07
0.3697931.5930251.634700e-07
0.371.5929771.603400e-07
0.3713991.5926571.503562e-07
0.3730131.5922931.388444e-07
0.3746331.5919331.272826e-07
0.3762611.5915771.156706e-07
0.3778951.5912251.040082e-07
0.3795371.5908779.229504e-08
0.381.5907798.899100e-08
0.3811861.5905328.474875e-08
0.3828421.5901917.882405e-08
0.3845051.5898547.287362e-08
0.3861751.589526.689734e-08
0.3878531.589196.089509e-08
0.3895381.5888635.486678e-08
0.391.5887755.321300e-08
0.391231.588545.060267e-08
0.392931.588224.699579e-08
0.3946371.5879044.337324e-08
0.3963511.5875913.973496e-08
0.3980731.5872813.608086e-08
0.3998021.5869743.241090e-08
0.41.5869393.199100e-08
0.4015391.5866713.133594e-08
0.4032831.586373.059344e-08
0.4050351.5860732.984772e-08
0.4067951.5857792.909876e-08
0.4085621.5854882.834655e-08
0.4103371.58522.759106e-08
0.412121.5849142.683230e-08
0.413911.5846322.607024e-08
0.4157081.5843522.530487e-08
0.4175141.5840762.453617e-08
0.4193281.5838022.376414e-08
0.421.5837012.347800e-08
0.4211491.5835312.354225e-08
0.4229791.5832622.364453e-08
0.4248171.5829972.374724e-08
0.4266621.5827342.385041e-08
0.4285161.5824732.395402e-08
0.4303771.5822152.405808e-08
0.4322471.581962.416259e-08
0.4341251.5817072.426756e-08
0.436011.5814572.437299e-08
0.4379051.5812092.447887e-08
0.4398071.5809642.458521e-08
0.441.5809392.459600e-08
0.4417181.5807212.437563e-08
0.4436371.5804812.412943e-08
0.4455641.5802422.388217e-08
0.4474991.5800062.363383e-08
0.4494431.5797732.338440e-08
0.4513961.5795412.313390e-08
0.4533571.5793122.288231e-08
0.4553261.5790852.262962e-08
0.4573041.5788612.237584e-08
0.4592911.5786382.212095e-08
0.461.5785592.203000e-08
0.4612861.5784182.184451e-08
0.463291.5781992.155554e-08
0.4653031.5779832.126532e-08
0.4673241.5777692.097383e-08
0.4693541.5775572.068108e-08
0.4713931.5773462.038706e-08
0.4734411.5771382.009176e-08
0.4754981.5769321.979518e-08
0.4775641.5767281.949731e-08
0.4796381.5765251.919815e-08
0.481.576491.914600e-08
0.4817221.5763251.887056e-08
0.4838151.5761261.853583e-08
0.4859171.5759291.819965e-08
0.4880271.5757341.786200e-08
0.4901481.5755411.752289e-08
0.4922771.5753491.718231e-08
0.4944151.575161.684025e-08
0.4965631.5749721.649670e-08
0.4987211.5747861.615165e-08
0.51.5746761.594700e-08
0.5008871.5746011.605331e-08
0.5030631.5744181.631408e-08
0.5052481.5742371.657598e-08
0.5074431.5740581.683902e-08
0.5096481.573881.710320e-08
0.5118621.5737031.736853e-08
0.5140861.5735291.763501e-08
0.5163191.5733551.790265e-08
0.5185621.5731841.817145e-08
0.5208151.5730141.844142e-08
0.5230771.5728451.871256e-08
0.5253491.5726781.898488e-08
0.5276321.5725121.925839e-08
0.5299241.5723481.953308e-08
0.5322261.5721861.980896e-08
0.5345381.5720242.008605e-08
0.536861.5718642.036434e-08
0.5391931.5717062.064383e-08
0.5415351.5715492.092454e-08
0.5438871.5713932.120647e-08
0.546251.5712392.148963e-08
0.5486231.5710862.177401e-08
0.551.5709982.193900e-08
0.5510071.5709342.197914e-08
0.55341.5707832.207460e-08
0.5558041.5706342.217048e-08
0.5582191.5704862.226677e-08
0.5606441.570342.236348e-08
0.563081.5701942.246061e-08
0.5655261.570052.255817e-08
0.5679821.5699072.265614e-08
0.570451.5697662.275454e-08
0.5729281.5696252.285337e-08
0.5754171.5694862.295263e-08
0.5779171.5693472.305232e-08
0.5804271.569212.315244e-08
0.5829491.5690742.325300e-08
0.5854811.568942.335400e-08
0.5880251.5688062.345543e-08
0.5905791.5686732.355731e-08
0.5931451.5685422.365962e-08
0.5957221.5684112.376238e-08
0.598311.5682822.386559e-08
0.61.5681982.393300e-08
0.6009091.5681532.406381e-08
0.6035191.5680262.443951e-08
0.6061411.56792.481684e-08
0.6087741.5677742.519582e-08
0.6114191.567652.557644e-08
0.6140751.5675272.595871e-08
0.6167431.5674042.634264e-08
0.6194221.5672832.672824e-08
0.6221131.5671632.711552e-08
0.6248161.5670432.750448e-08
0.627531.5669252.789513e-08
0.6302561.5668072.828747e-08
0.6329941.566692.868152e-08
0.6357441.5665742.907728e-08
0.6385061.5664592.947477e-08
0.641281.5663452.987397e-08
0.6440661.5662323.027492e-08
0.6468641.566123.067760e-08
0.6496741.5660083.108203e-08
0.651.5659953.112900e-08
0.6524961.5658983.152841e-08
0.6553311.5657883.198200e-08
0.6581781.5656793.243756e-08
0.6610371.565573.289511e-08
0.6639081.5654633.335463e-08
0.6667931.5653563.381616e-08
0.6696891.565253.427969e-08
0.6725991.5651453.474523e-08
0.6755211.5650413.521280e-08
0.6784551.5649373.568240e-08
0.6814031.5648353.615404e-08
0.6843631.5647323.662772e-08
0.6873361.5646313.710347e-08
0.6903221.564533.758128e-08
0.6933211.564433.806117e-08
0.6963331.5643313.854314e-08
0.6993581.5642323.902720e-08
0.71.5642123.913000e-08
0.7023961.5641353.987954e-08
0.7054471.5640374.083420e-08
0.7085121.5639414.179299e-08
0.711591.5638454.275596e-08
0.7146811.5637494.372311e-08
0.7177861.5636554.469446e-08
0.7209041.5635614.567003e-08
0.7240361.5634674.664983e-08
0.7271811.5633754.763390e-08
0.730341.5632824.862224e-08
0.7335131.5631914.961487e-08
0.73671.56315.061181e-08
0.73991.5630095.161309e-08
0.7431141.5629195.261871e-08
0.7463421.562835.362871e-08
0.7495851.5627415.464309e-08
0.7528411.5626535.566188e-08
0.7561121.5625655.668509e-08
0.7593961.5624785.771275e-08
0.7626951.5623925.874488e-08
0.7660091.5623065.978148e-08
0.7693361.562226.082259e-08
0.7726791.5621356.186823e-08
0.7760351.5620516.291840e-08
0.7794071.5619666.397314e-08
0.7827931.5618836.503246e-08
0.7861931.56186.609638e-08
0.7896091.5617176.716493e-08
0.7930391.5616356.823812e-08
0.7964841.5615536.931596e-08
0.7999441.5614727.039849e-08
0.81.5614717.041600e-08
0.8034191.5613916.849859e-08
0.8069091.5613116.654133e-08
0.8104151.5612316.457557e-08
0.8139351.5611516.260127e-08
0.8174711.5610726.061839e-08
0.8210231.5609935.862690e-08
0.8245891.5609155.662676e-08
0.8281721.5608375.461793e-08
0.8317691.560765.260037e-08
0.8353831.5606825.057405e-08
0.8390121.5606064.853892e-08
0.8426571.5605294.649495e-08
0.8463171.5604534.444211e-08
0.8499941.5603774.238034e-08
0.8536871.5603024.030962e-08
0.8573951.5602273.822991e-08
0.861121.5601523.614115e-08
0.8648611.5600783.404333e-08
0.8686181.5600043.193639e-08
0.8723911.559932.982030e-08
0.8761811.5598572.769501e-08
0.8799881.5597842.556049e-08
0.8838111.5597112.341670e-08
0.887651.5596392.126360e-08
0.8915061.5595671.910114e-08
0.8953791.5594951.692929e-08
0.8992691.5594231.474801e-08
0.91.559411.433800e-08
0.9031751.5593521.489552e-08
0.9070991.5592811.558439e-08
0.911041.559211.627625e-08
0.9149981.5591391.697112e-08
0.9189721.5590691.766900e-08
0.9229651.5589991.836992e-08
0.9269741.5589291.907388e-08
0.9310011.558861.978090e-08
0.9350461.558792.049099e-08
0.9391081.5587212.120416e-08
0.9431881.5586522.192044e-08
0.9472851.5585842.263982e-08
0.95141.5585152.336233e-08
0.9555331.5584472.408798e-08
0.9596841.5583792.481678e-08
0.9638531.5583112.554875e-08
0.9680411.5582432.628390e-08
0.9722461.5581752.702224e-08
0.976471.5581082.776379e-08
0.9807121.5580412.850856e-08
0.9849721.5579742.925656e-08
0.9892511.5579073.000782e-08
0.9935491.557843.076234e-08
0.9978651.5577733.152013e-08
11.5577413.189500e-08
1.00221.5577073.164927e-08
1.006551.5576413.116293e-08
1.010931.5575743.067448e-08
1.015321.5575083.018391e-08
1.019731.5574422.969120e-08
1.024161.5573762.919636e-08
1.028611.5573112.869937e-08
1.033081.5572452.820021e-08
1.037561.5571792.769889e-08
1.042071.5571142.719539e-08
1.04661.5570492.668971e-08
1.051151.5569832.618182e-08
1.055711.5569182.567173e-08
1.06031.5568532.515943e-08
1.06491.5567882.464489e-08
1.069531.5567232.412813e-08
1.074181.5566582.360912e-08
1.078841.5565932.308785e-08
1.083531.5565282.256432e-08
1.088241.5564632.203851e-08
1.092961.5563982.151042e-08
1.097711.5563332.098004e-08
1.102481.5562692.044735e-08
1.107271.5562041.991235e-08
1.112081.5561391.937503e-08
1.116911.5560741.883537e-08
1.121761.556011.829336e-08
1.126641.5559451.774900e-08
1.131531.555881.720228e-08
1.136451.5558151.665318e-08
1.141381.5557511.610169e-08
1.146341.5556861.554781e-08
1.151321.5556211.499153e-08
1.156321.5555561.443282e-08
1.161351.5554911.387169e-08
1.166391.5554261.330813e-08
1.171461.5553611.274211e-08
1.176551.5552961.217364e-08
1.181661.5552311.160269e-08
1.186791.5551661.102927e-08
1.191951.5551011.045335e-08
1.197131.5550359.874931e-09
1.21.5549999.554100e-09
1.202331.554971.153487e-08
1.207551.5549041.597814e-08
1.21281.5548392.044071e-08
1.218071.5547732.492266e-08
1.223361.5547072.942409e-08
1.228671.5546413.394507e-08
1.234011.5545753.848569e-08
1.239371.5545094.304604e-08
1.244751.5544434.762620e-08
1.250161.5543765.222625e-08
1.255591.554315.684629e-08
1.261051.5542436.148640e-08
1.266531.5541766.614667e-08
1.272031.5541097.082718e-08
1.277551.5540427.552802e-08
1.28311.5539758.024929e-08
1.288681.5539078.499107e-08
1.294281.553848.975344e-08
1.29991.5537729.453651e-08
1.305551.5537049.934035e-08
1.311221.5536361.041651e-07
1.316911.5535671.090107e-07
1.322641.5534991.138775e-07
1.328381.553431.187653e-07
1.334151.5533611.236744e-07
1.339951.5532921.286049e-07
1.345771.5532221.335567e-07
1.351621.5531531.385301e-07
1.357491.5530831.435250e-07
1.363381.5530131.485417e-07
1.369311.5529421.535801e-07
1.375261.5528711.586405e-07
1.381231.5528011.637228e-07
1.387231.5527291.688272e-07
1.393261.5526581.739538e-07
1.399311.5525861.791027e-07
1.41.5525781.796900e-07
1.405391.5525141.782963e-07
1.411491.5524421.767171e-07
1.417631.5523691.751311e-07
1.423781.5522961.735382e-07
1.429971.5522231.719384e-07
1.436181.552151.703316e-07
1.442421.5520761.687179e-07
1.448691.5520021.670971e-07
1.454981.5519271.654693e-07
1.46131.5518521.638345e-07
1.467651.5517771.621925e-07
1.474031.5517021.605434e-07
1.480431.5516261.588871e-07
1.486861.5515491.572237e-07
1.493321.5514731.555530e-07
1.499811.5513961.538750e-07
1.506321.5513181.521898e-07
1.512871.5512411.504972e-07
1.519441.5511631.487973e-07
1.526041.5510841.470900e-07
1.532671.5510051.453753e-07
1.539331.5509261.436532e-07
1.546011.5508461.419235e-07
1.552731.5507661.401864e-07
1.559481.5506851.384417e-07
1.566251.5506041.366894e-07
1.573051.5505221.349295e-07
1.579891.550441.331619e-07
1.586751.5503581.313867e-07
1.593641.5502751.296038e-07
1.61.5501981.279600e-07
1.600571.5501911.287518e-07
1.607521.5501081.384456e-07
1.61451.5500231.481816e-07
1.621521.5499381.579599e-07
1.628561.5498531.677806e-07
1.635641.5497671.776440e-07
1.642741.549681.875503e-07
1.649881.5495931.974996e-07
1.657051.5495062.074921e-07
1.664251.5494182.175280e-07
1.671481.5493292.276076e-07
1.678741.549242.377309e-07
1.686031.549152.478982e-07
1.693351.549062.581096e-07
1.700711.5489692.683655e-07
1.70811.5488782.786658e-07
1.715521.5487862.890110e-07
1.722971.5486932.994010e-07
1.730461.54863.098362e-07
1.737971.5485063.203168e-07
1.745521.5484113.308428e-07
1.753111.5483163.414146e-07
1.760721.548223.520323e-07
1.768371.5481243.626962e-07
1.776051.5480273.734063e-07
1.783771.5479293.841630e-07
1.791521.547833.949665e-07
1.79931.5477314.058168e-07
1.81.5477224.067900e-07
1.807121.5476314.183940e-07
1.814971.5475314.311911e-07
1.822851.5474294.440439e-07
1.830771.5473274.569525e-07
1.838731.5472244.699172e-07
1.846711.5471214.829382e-07
1.854741.5470174.960158e-07
1.862791.5469125.091501e-07
1.870891.5468065.223416e-07
1.879011.5466995.355903e-07
1.887181.5465925.488966e-07
1.895371.5464845.622607e-07
1.903611.5463755.756829e-07
1.911881.5462655.891634e-07
1.920181.5461546.027024e-07
1.928531.5460436.163003e-07
1.93691.545936.299572e-07
1.945321.5458176.436735e-07
1.953771.5457036.574493e-07
1.962261.5455886.712850e-07
1.970781.5454726.851808e-07
1.979341.5453556.991369e-07
1.987941.5452387.131537e-07
1.996581.5451197.272314e-07
21.5450727.328100e-07
2.005251.5457.723314e-07
2.013961.5448798.378921e-07
2.022711.5447589.037376e-07
2.03151.5446359.698691e-07
2.040321.5445121.036288e-06
2.049191.5443871.102995e-06
2.058091.5442621.169992e-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
—