Optical constants

Refractive index of K-GFK70(M) (SUMITA)

K-GFK70(M): n,k 0.36–1.55 µm

Data
formula 3 + tabulated k
Range
0.36–1.55 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.36–1.55 µm
Refractive index n
1.56627
Extinction coefficient k
1.40486e-08
Permittivity ε1
2.45321
Permittivity ε2
4.40080e-08
Absorption coefficient α
0.00300443 cm⁻¹
Penetration depth δ = λ/(2πk)
6.65683e+09 nm
Abbe number Vd
71.326
Chromatic dispersion dn/dλ
-0.0409429 µm⁻¹
Group index ng
1.59033
Group velocity dispersion
73.1638 fs²/mm
Dispersion parameter D
-399.147 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

# K-GFK70(M) (SUMITA): K-GFK70(M)
sumita_k_gfk70_m = ls.fetch_refractiveindex("specs", "SUMITA-optical", "K-GFK70(M)", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(sumita_k_gfk70_m.range_nm)  # (360, 1550) nm
eps = sumita_k_gfk70_m.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=2.4208616−0.0057307899⁢λ2.0+0.011396384⁢λ−2.0+0.00014964607⁢λ−4.0+3.8084377×10-6⁢λ−6.0−3.2734834×10-7⁢λ−8.0

Valid from 0.36 to 1.55 µm.

Coefficients as stored
CiValue
C12.4208616
C2-0.0057307899
C32.0
C40.011396384
C5-2.0
C60.00014964607
C7-4.0
C83.8084377e-06
C9-6.0
C10-3.2734834e-07
C11-8.0

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: -2.47e-05 -1.68e-09 -2.49e-11 3.77e-07 3.45e-10 0.178
nd
1.56627
Vd
71.3
glass code
569713
density
value: 4460
thermal expansion
value: 1.32e-05, temperature range: 243 343; value: 1.56e-05, temperature range: 293 573
dPgF
0.0207
resistance
acid: 1.0; climatic: 1.0

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = -1.10e-05 K⁻¹ at 633 nm, dn/dT = -1.12e-05 K⁻¹ at 1310 nm, dn/dT = -1.12e-05 K⁻¹ at 1550 nm

References

Cite

SUMITA Zemax catalog 2017-02-02 (obtained from http://www.sumita-opt.co.jp); See also SUMITA optical glass data book; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)

Data

Computed on 416 wavelengths, the same grid as the API and the library
K-GFK70(M) (SUMITA), K-GFK70(M): n and k versus wavelength
λ (µm)nk
0.361.586689.317200e-08
0.361321.5864348.833018e-08
0.3626441.586198.347061e-08
0.3639731.5859487.859322e-08
0.3653081.5857087.369796e-08
0.3666471.5854696.878475e-08
0.3679911.5852336.385354e-08
0.369341.5849995.890424e-08
0.371.5848855.648100e-08
0.3706931.5847665.509598e-08
0.3720521.5845365.238188e-08
0.3734161.5843074.965782e-08
0.3747851.584084.692378e-08
0.3761591.5838554.417972e-08
0.3775371.5836314.142560e-08
0.3789211.583413.866139e-08
0.381.5832393.650700e-08
0.380311.583193.634200e-08
0.3817041.5829723.560091e-08
0.3831041.5827563.485711e-08
0.3845081.5825413.411057e-08
0.3859171.5823283.336131e-08
0.3873321.5821173.260929e-08
0.3887521.5819083.185452e-08
0.391.5817263.119100e-08
0.3901771.58173.109154e-08
0.3916071.5814943.028717e-08
0.3930431.581292.947986e-08
0.3944831.5810872.866958e-08
0.3959291.5808862.785634e-08
0.3973811.5806862.704011e-08
0.3988371.5804882.622090e-08
0.41.5803322.556700e-08
0.4002991.5802922.558614e-08
0.4017671.5800972.567998e-08
0.4032391.5799032.577416e-08
0.4047171.5797122.586868e-08
0.4062011.5795222.596356e-08
0.407691.5793332.605878e-08
0.4091841.5791462.615434e-08
0.4106841.578962.625026e-08
0.412191.5787762.634653e-08
0.4137011.5785932.644316e-08
0.4152171.5784122.654014e-08
0.4167391.5782322.663747e-08
0.4182671.5780532.673516e-08
0.41981.5778762.683321e-08
0.421.5778532.684600e-08
0.4213391.5777012.693155e-08
0.4228831.5775262.703024e-08
0.4244331.5773532.712929e-08
0.4259891.5771822.722871e-08
0.4275511.5770122.732849e-08
0.4291181.5768432.742864e-08
0.4306911.5766762.752915e-08
0.432271.5765092.763003e-08
0.4338541.5763452.773128e-08
0.4354451.5761812.783291e-08
0.4370411.5760192.793490e-08
0.4386431.5758582.803727e-08
0.441.5757232.812400e-08
0.4402511.5756982.814002e-08
0.4418641.5755392.824314e-08
0.4434841.5753822.834664e-08
0.445111.5752262.845052e-08
0.4467411.5750712.855477e-08
0.4483791.5749182.865942e-08
0.4500231.5747652.876444e-08
0.4516721.5746142.886985e-08
0.4533281.5744642.897565e-08
0.454991.5743152.908183e-08
0.4566571.5741682.918841e-08
0.4583311.5740212.929537e-08
0.461.5738772.940200e-08
0.4600111.5738762.940273e-08
0.4616981.5737312.951056e-08
0.463391.5735882.961879e-08
0.4650891.5734462.972742e-08
0.4667931.5733052.983644e-08
0.4685051.5731652.994586e-08
0.4702221.5730273.005569e-08
0.4719461.5728893.016592e-08
0.4736751.5727523.027655e-08
0.4754121.5726173.038759e-08
0.4771541.5724823.049903e-08
0.4789041.5723483.061088e-08
0.481.5722663.068100e-08
0.4806591.5722163.045904e-08
0.4824211.5720842.986563e-08
0.4841891.5719542.927004e-08
0.4859641.5718242.867227e-08
0.4877461.5716962.807231e-08
0.4895331.5715682.747015e-08
0.4913281.5714422.686578e-08
0.4931291.5713162.625920e-08
0.4949361.5711922.565039e-08
0.4967511.5710682.503935e-08
0.4985721.5709452.442608e-08
0.51.570852.394500e-08
0.5003991.5708232.385881e-08
0.5022331.5707022.346279e-08
0.5040741.5705822.306532e-08
0.5059221.5704632.266640e-08
0.5077771.5703452.226601e-08
0.5096381.5702282.186415e-08
0.5115061.5701112.146082e-08
0.5133811.5699952.105601e-08
0.5152631.5698812.064972e-08
0.5171521.5697672.024193e-08
0.5190471.5696541.983266e-08
0.520951.5695421.942188e-08
0.522861.569431.900960e-08
0.5247761.569321.859580e-08
0.52671.569211.818049e-08
0.5286311.5691011.776366e-08
0.5305681.5689931.734529e-08
0.5325131.5688861.692540e-08
0.5344651.5687791.650397e-08
0.5364241.5686741.608099e-08
0.5383911.5685691.565646e-08
0.5403641.5684651.523037e-08
0.5423451.5683611.480272e-08
0.5443331.5682581.437351e-08
0.5463281.5681571.394272e-08
0.5483311.5680551.351035e-08
0.551.5679721.315000e-08
0.5503411.5679551.315815e-08
0.5523581.5678551.320636e-08
0.5543831.5677561.325475e-08
0.5564151.5676581.330332e-08
0.5584551.567561.335207e-08
0.5605021.5674641.340099e-08
0.5625561.5673671.345010e-08
0.5646191.5672721.349938e-08
0.5666881.5671771.354885e-08
0.5687651.5670831.359849e-08
0.570851.566991.364832e-08
0.5729431.5668971.369833e-08
0.5750431.5668051.374853e-08
0.5771511.5667131.379891e-08
0.5792671.5666221.384947e-08
0.581391.5665321.390022e-08
0.5835211.5664431.395115e-08
0.585661.5663541.400227e-08
0.5878071.5662661.405358e-08
0.5899611.5661781.410508e-08
0.5921241.5660911.415676e-08
0.5942951.5660041.420864e-08
0.5964731.5659191.426070e-08
0.5986591.5658331.431296e-08
0.61.5657821.434500e-08
0.6008541.5657491.427686e-08
0.6030561.5656651.410110e-08
0.6052671.5655811.392470e-08
0.6074861.5654981.374765e-08
0.6097121.5654161.356995e-08
0.6119471.5653341.339160e-08
0.6141911.5652531.321259e-08
0.6164421.5651721.303293e-08
0.6187021.5650921.285261e-08
0.620971.5650131.267163e-08
0.6232461.5649341.248999e-08
0.625531.5648551.230768e-08
0.6278231.5647771.212470e-08
0.6301251.56471.194105e-08
0.6324341.5646231.175673e-08
0.6347531.5645461.157173e-08
0.6370791.564471.138606e-08
0.6394151.5643951.119970e-08
0.6417591.564321.101266e-08
0.6441111.5642461.082494e-08
0.6464721.5641721.063653e-08
0.6488421.5640981.044742e-08
0.651.5640631.035500e-08
0.651221.5640261.037445e-08
0.6536071.5639531.041250e-08
0.6560031.5638811.045069e-08
0.6584081.563811.048902e-08
0.6608211.5637381.052749e-08
0.6632441.5636681.056610e-08
0.6656751.5635981.060486e-08
0.6681151.5635281.064375e-08
0.6705641.5634591.068279e-08
0.6730221.563391.072197e-08
0.6754891.5633221.076130e-08
0.6779651.5632541.080077e-08
0.680451.5631861.084038e-08
0.6829451.5631191.088014e-08
0.6854481.5630521.092004e-08
0.6879611.5629861.096009e-08
0.6904821.562921.100029e-08
0.6930131.5628551.104063e-08
0.6955541.562791.108113e-08
0.6981031.5627251.112177e-08
0.71.5626781.115200e-08
0.7006621.5626611.116255e-08
0.7032311.5625971.120347e-08
0.7058091.5625341.124453e-08
0.7083961.5624711.128574e-08
0.7109921.5624081.132711e-08
0.7135991.5623461.136863e-08
0.7162141.5622841.141030e-08
0.718841.5622221.145212e-08
0.7214751.5621611.149409e-08
0.7241191.56211.153622e-08
0.7267741.562041.157851e-08
0.7294381.561981.162095e-08
0.7321121.561921.166354e-08
0.7347951.5618611.170629e-08
0.7374891.5618021.174920e-08
0.7401921.5617431.179226e-08
0.7429051.5616841.183548e-08
0.7456291.5616261.187886e-08
0.7483621.5615691.192240e-08
0.7511051.5615111.196610e-08
0.7538581.5614541.200996e-08
0.7566221.5613971.205398e-08
0.7593951.5613411.209816e-08
0.7621791.5612851.214251e-08
0.7649731.5612291.218701e-08
0.7677771.5611741.223168e-08
0.7705911.5611181.227652e-08
0.7734161.5610631.232151e-08
0.7762511.5610091.236668e-08
0.7790961.5609551.241200e-08
0.7819521.5609011.245750e-08
0.7848181.5608471.250316e-08
0.7876951.5607931.254899e-08
0.7905831.560741.259498e-08
0.7934811.5606871.264115e-08
0.7963891.5606351.268748e-08
0.7993091.5605821.273398e-08
0.81.560571.274500e-08
0.8022381.560531.278066e-08
0.8051791.5604781.282751e-08
0.8081311.5604271.287453e-08
0.8110931.5603761.292172e-08
0.8140661.5603251.296908e-08
0.817051.5602741.301662e-08
0.8200451.5602231.306433e-08
0.8230511.5601731.311222e-08
0.8260681.5601231.316028e-08
0.8290961.5600731.320852e-08
0.8321351.5600241.325694e-08
0.8351861.5599741.330553e-08
0.8382471.5599251.335431e-08
0.841321.5598761.340326e-08
0.8444041.5598281.345239e-08
0.8474991.5597791.350169e-08
0.8506061.5597311.355119e-08
0.8537241.5596831.360086e-08
0.8568531.5596351.365071e-08
0.8599941.5595881.370075e-08
0.8631461.559541.375097e-08
0.866311.5594931.380137e-08
0.8694861.5594461.385196e-08
0.8726731.55941.390274e-08
0.8758721.5593531.395370e-08
0.8790821.5593071.400484e-08
0.8823051.5592611.405618e-08
0.8855391.5592151.410770e-08
0.8887851.5591691.415941e-08
0.8920431.5591241.421132e-08
0.8953131.5590781.426341e-08
0.8985951.5590331.431569e-08
0.9018891.5589881.436817e-08
0.9051951.5589431.442083e-08
0.9085131.5588981.447369e-08
0.9118431.5588541.452675e-08
0.9151861.558811.457999e-08
0.918541.5587651.463344e-08
0.9219071.5587211.468708e-08
0.9252871.5586781.474091e-08
0.9286781.5586341.479494e-08
0.9320831.558591.484918e-08
0.9354991.5585471.490361e-08
0.9389281.5585041.495824e-08
0.942371.5584611.501307e-08
0.9458241.5584181.506810e-08
0.9492911.5583751.512333e-08
0.9527711.5583321.517876e-08
0.9562641.558291.523440e-08
0.9597691.5582471.529024e-08
0.9632871.5582051.534629e-08
0.9668181.5581631.540254e-08
0.9703621.5581211.545900e-08
0.9739191.5580791.551567e-08
0.9774891.5580381.557254e-08
0.9810721.5579961.562962e-08
0.9846681.5579541.568691e-08
0.9882781.5579131.574441e-08
0.9919011.5578721.580212e-08
0.9955361.5578311.586005e-08
0.9991861.557791.591818e-08
1.002851.5577491.597653e-08
1.006521.5577081.603509e-08
1.010211.5576671.609387e-08
1.013921.5576271.615286e-08
1.017631.5575861.621207e-08
1.021361.5575461.627150e-08
1.025111.5575051.633114e-08
1.028871.5574651.639100e-08
1.032641.5574251.645108e-08
1.036421.5573851.651139e-08
1.040221.5573451.657191e-08
1.044031.5573051.663265e-08
1.047861.5572651.669362e-08
1.05171.5572251.675481e-08
1.055561.5571861.681623e-08
1.059431.5571461.687787e-08
1.061.557141.688700e-08
1.063311.5571071.693974e-08
1.067211.5570671.700184e-08
1.071121.5570281.706416e-08
1.075051.5569891.712671e-08
1.078991.5569491.718950e-08
1.082941.556911.725251e-08
1.086911.5568711.731575e-08
1.09091.5568321.737923e-08
1.094891.5567931.744294e-08
1.098911.5567541.750688e-08
1.102941.5567151.757105e-08
1.106981.5566761.763547e-08
1.111041.5566371.770011e-08
1.115111.5565991.776500e-08
1.11921.556561.783012e-08
1.12331.5565211.789548e-08
1.127421.5564821.796108e-08
1.131551.5564441.802692e-08
1.13571.5564051.809301e-08
1.139861.5563671.815933e-08
1.144041.5563281.822590e-08
1.148231.556291.829271e-08
1.152441.5562511.835977e-08
1.156671.5562131.842707e-08
1.160911.5561741.849462e-08
1.165161.5561361.856241e-08
1.169431.5560971.863046e-08
1.173721.5560591.869875e-08
1.178021.5560211.876730e-08
1.182341.5559821.883610e-08
1.186671.5559441.890514e-08
1.191021.5559051.897445e-08
1.195391.5558671.904400e-08
1.199771.5558291.911381e-08
1.204171.555791.918388e-08
1.208581.5557521.925420e-08
1.213011.5557141.932478e-08
1.217461.5556751.939562e-08
1.221921.5556371.946672e-08
1.22641.5555981.953808e-08
1.23091.555561.960970e-08
1.235411.5555221.968159e-08
1.239941.5554831.975374e-08
1.244481.5554451.982615e-08
1.249041.5554061.989883e-08
1.253621.5553681.997177e-08
1.258221.5553292.004498e-08
1.262831.555292.011846e-08
1.267461.5552522.019221e-08
1.272111.5552132.026623e-08
1.276771.5551752.034052e-08
1.281451.5551362.041509e-08
1.286151.5550972.048992e-08
1.290861.5550582.056503e-08
1.295591.5550192.064042e-08
1.300341.5549812.071608e-08
1.305111.5549422.079202e-08
1.309891.5549032.086824e-08
1.314691.5548642.094474e-08
1.319511.5548242.102151e-08
1.324351.5547852.109857e-08
1.32921.5547462.117592e-08
1.334081.5547072.125354e-08
1.338971.5546682.133145e-08
1.343881.5546282.140965e-08
1.34881.5545892.148813e-08
1.353751.5545492.156690e-08
1.358711.554512.164596e-08
1.363691.554472.172531e-08
1.368691.554432.180495e-08
1.37371.554392.188488e-08
1.378741.554352.196510e-08
1.383791.554312.204562e-08
1.388871.554272.212643e-08
1.393961.554232.220754e-08
1.399071.554192.228895e-08
1.40421.5541492.237065e-08
1.409341.5541092.245266e-08
1.414511.5540682.253496e-08
1.419691.5540282.261757e-08
1.42491.5539872.270048e-08
1.430121.5539462.278370e-08
1.435361.5539052.286721e-08
1.440621.5538642.295104e-08
1.445911.5538232.303517e-08
1.451211.5537822.311961e-08
1.456521.553742.320436e-08
1.461861.5536992.328942e-08
1.467221.5536572.337480e-08
1.47261.5536162.346048e-08
1.4781.5535742.354648e-08
1.483421.5535322.363280e-08
1.488851.553492.371943e-08
1.494311.5534472.380638e-08
1.499791.5534052.389365e-08
1.51.5534032.389700e-08
1.505291.5533632.398123e-08
1.51081.553322.406914e-08
1.516341.5532772.415738e-08
1.52191.5532342.424593e-08
1.527481.5531912.433481e-08
1.533081.5531482.442402e-08
1.53871.5531052.451355e-08
1.544341.5530612.460341e-08
1.551.5530172.469360e-08

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
—