Optical constants

Refractive index of K5G20 (SCHOTT)

K5G20: n,k 0.37–2.5 µm

Data
formula 2 + tabulated k
Range
0.37–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength. Note: k data cover 380-2500 nm only; k = 0 elsewhere in the n range 370-2500 nm.

At one wavelength

Range 0.37–2.5 µm
Refractive index n
1.52344
Extinction coefficient k
3.28297e-08
Permittivity ε1
2.32086
Permittivity ε2
1.00028e-07
Absorption coefficient α
0.00702093 cm⁻¹
Penetration depth δ = λ/(2πk)
2.84863e+09 nm
Abbe number Vd
56.76
Chromatic dispersion dn/dλ
-0.0474975 µm⁻¹
Group index ng
1.55135
Group velocity dispersion
84.3925 fs²/mm
Dispersion parameter D
-460.406 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

# K5G20 (SCHOTT): K5G20
schott_k5g20 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "K5G20", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_k5g20.range_nm)  # (370, 2500) nm
eps = schott_k5g20.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=1.14094396λ2λ2−0.00694945478+0.14500119λ2λ2−0.0310574444+37.4705786λ2λ2−4536.25624

Valid from 0.37 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.14094396
C30.00694945478
C40.14500119
C50.0310574444
C637.4705786
C74536.25624

Comments and conditions

inquiry glass

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: -2.22e-06 8.45e-09 -3.31e-11 5.44e-07 4.95e-10 0.214
nd
1.52344
Vd
56.76
glass code
523568.259
glass status
special
density
value: 2593
thermal expansion
value: 8.99e-06, temperature range: 243 343; value: 1.028e-05, temperature range: 293 573
dPgF
0.0017
resistance
acid: 1.0; stain: 0.0; alkali: 1.0

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = -2.97e-07 K⁻¹ at 633 nm, dn/dT = -8.02e-07 K⁻¹ at 1310 nm, dn/dT = -8.39e-07 K⁻¹ at 1550 nm
Notes on the source data (kept exactly as published):
  • k data cover 380-2500 nm only; k = 0 elsewhere in the n range 370-2500 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 417 wavelengths, the same grid as the API and the library
K5G20 (SCHOTT), K5G20: n and k versus wavelength
λ (µm)nk
0.371.5454380
0.3717761.5450670
0.373561.54470
0.3753531.5443380
0.3771551.5439810
0.3789651.5436270
0.381.5434282.467800e-06
0.3807841.5432782.365932e-06
0.3826121.5429332.128533e-06
0.3844481.5425931.889995e-06
0.3862941.5422561.650311e-06
0.3881481.5419231.409478e-06
0.391.5415961.168900e-06
0.3900111.5415941.168313e-06
0.3918831.5412691.067313e-06
0.3937641.5409489.658272e-07
0.3956541.5406318.638545e-07
0.3975531.5403177.613925e-07
0.3994611.5400076.584386e-07
0.41.539926.293600e-07
0.4013781.5397015.929210e-07
0.4033051.5393985.419910e-07
0.4051.5391354.971800e-07
0.4052411.5390984.934591e-07
0.4071861.5388024.633920e-07
0.409141.5385094.331807e-07
0.4111041.538224.028243e-07
0.4130771.5379343.723223e-07
0.415061.5376513.416738e-07
0.4170521.5373723.108783e-07
0.4190541.5370952.799349e-07
0.421.5369662.653100e-07
0.4210651.5368222.584137e-07
0.4230861.5365512.453300e-07
0.4251171.5362842.321835e-07
0.4271581.536022.189740e-07
0.4292081.5357582.057010e-07
0.4312681.53551.923643e-07
0.4333381.5352441.789636e-07
0.4354181.5349921.654986e-07
0.4361.5349211.617300e-07
0.4375081.5347411.582451e-07
0.4396081.5344941.533916e-07
0.4417181.534251.485148e-07
0.4438381.5340081.436146e-07
0.4459681.5337681.386908e-07
0.4481091.5335311.337435e-07
0.450261.5332971.287723e-07
0.4524211.5330661.237773e-07
0.4545921.5328361.187584e-07
0.4567741.532611.137153e-07
0.4589671.5323851.086481e-07
0.461.5322811.062600e-07
0.461171.5321631.050041e-07
0.4633831.5319441.026275e-07
0.4656071.5317271.002395e-07
0.4678421.5315129.784001e-08
0.4700881.5312999.542901e-08
0.4723441.5310889.300645e-08
0.4746111.530889.057225e-08
0.4768891.5306748.812637e-08
0.4791781.530478.566875e-08
0.4814781.5302688.319934e-08
0.4837891.5300698.071807e-08
0.4861111.5298717.822489e-08
0.4884451.5296757.571975e-08
0.4907891.5294827.320258e-08
0.4931451.529297.067333e-08
0.4955121.52916.813194e-08
0.497891.5289136.557835e-08
0.51.5287486.331300e-08
0.500281.5287276.318467e-08
0.5026811.5285436.208359e-08
0.5050941.5283616.097723e-08
0.5075181.528185.986555e-08
0.5099541.5280025.874855e-08
0.5124021.5278255.762618e-08
0.5148611.527655.649842e-08
0.5173331.5274775.536525e-08
0.5198161.5273055.422664e-08
0.5223111.5271365.308257e-08
0.5248181.5269685.193300e-08
0.5273371.5268015.077792e-08
0.5298681.5266364.961729e-08
0.5324111.5264734.845110e-08
0.5349671.5263124.727930e-08
0.5375341.5261514.610188e-08
0.5401141.5259934.491881e-08
0.5427071.5258364.373006e-08
0.5453121.5256814.253560e-08
0.5461.525644.222000e-08
0.5479291.5255274.172717e-08
0.5505591.5253744.105529e-08
0.5532021.5252234.038019e-08
0.5558571.5250733.970185e-08
0.5585251.5249253.902025e-08
0.5612061.5247783.833538e-08
0.5638991.5246333.764723e-08
0.5666061.5244893.695577e-08
0.5693261.5243463.626099e-08
0.5720581.5242053.556287e-08
0.5748041.5240653.486141e-08
0.5775631.5239263.415658e-08
0.581.5238053.353400e-08
0.5803351.5237893.350294e-08
0.5831211.5236523.324479e-08
0.585921.5235173.298540e-08
0.5887321.5233843.272477e-08
0.5915581.5232513.246289e-08
0.5943971.523123.219975e-08
0.597251.522993.193535e-08
0.6001171.5228613.166968e-08
0.6029971.5227333.140274e-08
0.6058911.5226063.113451e-08
0.60881.522483.086500e-08
0.6117221.5223563.059419e-08
0.6146581.5222323.032208e-08
0.6176081.522113.004867e-08
0.621.5220122.982700e-08
0.6205731.5219892.979355e-08
0.6235511.5218692.961952e-08
0.6265441.521752.944466e-08
0.6295511.5216312.926896e-08
0.6325731.5215142.909242e-08
0.6356091.5213982.891503e-08
0.638661.5212832.873678e-08
0.6417261.5211692.855768e-08
0.6448061.5210562.837772e-08
0.6479011.5209432.819690e-08
0.651011.5208322.801521e-08
0.6541351.5207222.783265e-08
0.6572751.5206122.764921e-08
0.661.5205182.749000e-08
0.660431.5205042.738694e-08
0.66361.5203962.662671e-08
0.6667851.5202892.586283e-08
0.6699851.5201832.509528e-08
0.6732011.5200782.432405e-08
0.6764321.5199742.354912e-08
0.6796791.519872.277047e-08
0.6829411.5197682.198808e-08
0.6862191.5196662.120194e-08
0.6895131.5195652.041202e-08
0.6928231.5194641.961831e-08
0.6961481.5193651.882080e-08
0.6994891.5192661.801945e-08
0.71.5192511.789700e-08
0.7028471.5191681.788922e-08
0.706221.5190711.788000e-08
0.709611.5189741.787073e-08
0.7130161.5188791.786142e-08
0.7164381.5187831.785207e-08
0.7198771.5186891.784267e-08
0.7233321.5185951.783322e-08
0.7268041.5185021.782373e-08
0.7302931.518411.781420e-08
0.7337981.5183181.780462e-08
0.737321.5182271.779499e-08
0.7408591.5181371.778532e-08
0.7444151.5180471.777560e-08
0.7479881.5179581.776583e-08
0.7515781.5178691.775602e-08
0.7551861.5177811.774616e-08
0.7588111.5176941.773625e-08
0.7624531.5176071.772630e-08
0.7661121.5175211.771629e-08
0.769791.5174351.770624e-08
0.7734841.517351.769614e-08
0.7771971.5172651.768599e-08
0.7809271.5171811.767580e-08
0.7846761.5170981.766555e-08
0.7884421.5170151.765526e-08
0.7922261.5169321.764491e-08
0.7960291.516851.763452e-08
0.799851.5167691.762408e-08
0.8036891.5166881.761358e-08
0.8075461.5166071.760304e-08
0.8114221.5165271.759245e-08
0.8153171.5164481.758180e-08
0.8192311.5163691.757110e-08
0.8231631.516291.756036e-08
0.8271141.5162121.754956e-08
0.8310841.5161341.753870e-08
0.8350731.5160571.752780e-08
0.8390811.515981.751685e-08
0.8431081.5159031.750584e-08
0.8471551.5158271.749478e-08
0.8512211.5157511.748366e-08
0.8553071.5156761.747249e-08
0.8594121.5156011.746127e-08
0.8635371.5155261.745000e-08
0.8676821.5154521.743867e-08
0.8718471.5153781.742729e-08
0.8760321.5153041.741585e-08
0.8802361.5152311.740435e-08
0.8844611.5151581.739281e-08
0.8887071.5150851.738120e-08
0.8929721.5150131.736954e-08
0.8972581.5149411.735783e-08
0.9015651.5148691.734606e-08
0.9058921.5147981.733423e-08
0.910241.5147271.732234e-08
0.9146091.5146561.731040e-08
0.9189991.5145861.729840e-08
0.923411.5145151.728635e-08
0.9278431.5144451.727423e-08
0.9322961.5143761.726206e-08
0.9367711.5143061.724983e-08
0.9412671.5142371.723754e-08
0.9457851.5141681.722519e-08
0.9503251.5140991.721278e-08
0.9548861.514031.720031e-08
0.9594691.5139621.718778e-08
0.9640751.5138941.717520e-08
0.9687021.5138261.716255e-08
0.9733521.5137581.714984e-08
0.9780231.513691.713707e-08
0.9827181.5136231.712424e-08
0.9874351.5135561.711135e-08
0.9921741.5134881.709839e-08
0.9969361.5134221.708537e-08
1.001721.5133551.707229e-08
1.006531.5132881.705915e-08
1.011361.5132221.704595e-08
1.016221.5131551.703268e-08
1.021091.5130891.701935e-08
1.025991.5130231.700595e-08
1.030921.5129571.699249e-08
1.035871.5128911.697896e-08
1.040841.5128251.696537e-08
1.045831.512761.695172e-08
1.050851.5126941.693800e-08
1.05591.5126281.692421e-08
1.061.5125751.691300e-08
1.060971.5125631.712144e-08
1.066061.5124981.822007e-08
1.071181.5124321.932398e-08
1.076321.5123672.043318e-08
1.081481.5123022.154771e-08
1.086671.5122372.266759e-08
1.091891.5121712.379284e-08
1.097131.5121062.492350e-08
1.10241.5120412.605958e-08
1.107691.5119762.720112e-08
1.1131.5119112.834813e-08
1.118351.5118462.950065e-08
1.123711.5117813.065870e-08
1.129111.5117163.182231e-08
1.134531.5116513.299151e-08
1.139971.5115863.416631e-08
1.145451.5115213.534676e-08
1.150941.5114563.653287e-08
1.156471.5113913.772468e-08
1.162021.5113253.892220e-08
1.16761.511264.012548e-08
1.17321.5111954.133452e-08
1.178831.5111294.254938e-08
1.184491.5110644.377006e-08
1.190171.5109984.499660e-08
1.195891.5109334.622903e-08
1.201631.5108674.746737e-08
1.207391.5108014.871166e-08
1.213191.5107364.996192e-08
1.219011.510675.121819e-08
1.224861.5106035.248048e-08
1.230741.5105375.374883e-08
1.236651.5104715.502327e-08
1.242591.5104055.630382e-08
1.248551.5103385.759052e-08
1.254541.5102715.888340e-08
1.260561.5102046.018248e-08
1.266621.5101376.148780e-08
1.272691.510076.279939e-08
1.27881.5100036.411726e-08
1.284941.5099356.544147e-08
1.291111.5098676.677203e-08
1.297311.50986.810898e-08
1.303531.5097316.945234e-08
1.309791.5096637.080215e-08
1.316081.5095957.215844e-08
1.322391.5095267.352124e-08
1.328741.5094577.489059e-08
1.335121.5093887.626650e-08
1.341531.5093197.764902e-08
1.347971.5092497.903817e-08
1.354441.5091798.043400e-08
1.360941.5091098.183652e-08
1.367471.5090398.324577e-08
1.374031.5089688.466179e-08
1.380631.5088978.608461e-08
1.387251.5088268.751425e-08
1.393911.5087548.895075e-08
1.40061.5086839.039416e-08
1.407331.508619.184448e-08
1.414081.5085389.330177e-08
1.420871.5084659.476606e-08
1.427691.5083929.623737e-08
1.434541.5083199.771575e-08
1.441431.5082459.920122e-08
1.448341.5081711.006938e-07
1.45531.5080971.021936e-07
1.462281.5080221.037005e-07
1.46931.5079471.052147e-07
1.476351.5078721.067362e-07
1.483441.5077961.082650e-07
1.490561.507721.098011e-07
1.497711.5076431.113446e-07
1.50491.5075661.128954e-07
1.512131.5074891.144538e-07
1.519381.5074111.160196e-07
1.526681.5073331.175929e-07
1.531.5072971.183100e-07
1.5341.5072541.328932e-07
1.541371.5071751.597108e-07
1.548771.5070961.866572e-07
1.55621.5070162.137328e-07
1.563671.5069362.409385e-07
1.571171.5068552.682747e-07
1.578711.5067742.957421e-07
1.586291.5066923.233414e-07
1.593911.5066093.510731e-07
1.601561.5065273.789380e-07
1.609241.5064434.069366e-07
1.616971.506364.350696e-07
1.624731.5062754.633376e-07
1.632531.5061914.917413e-07
1.640361.5061055.202813e-07
1.648241.5060195.489583e-07
1.656151.5059335.777730e-07
1.66411.5058466.067259e-07
1.672081.5057586.358179e-07
1.680111.505676.650494e-07
1.688171.5055826.944213e-07
1.696281.5054927.239342e-07
1.704421.5054027.535887e-07
1.71261.5053127.833855e-07
1.720821.5052218.133254e-07
1.729081.5051298.434090e-07
1.737381.5050378.736369e-07
1.745721.5049449.040100e-07
1.75411.504859.345288e-07
1.762521.5047569.651942e-07
1.770981.5046619.960067e-07
1.779481.5045651.026967e-06
1.788021.5044691.058076e-06
1.79661.5043721.089334e-06
1.805221.5042741.120743e-06
1.813891.5041761.152302e-06
1.822591.5040771.184012e-06
1.831341.5039771.215875e-06
1.840131.5038761.247891e-06
1.848971.5037751.280060e-06
1.857841.5036731.312384e-06
1.866761.503571.344863e-06
1.875721.5034661.377498e-06
1.884721.5033621.410290e-06
1.893771.5032561.443238e-06
1.902861.503151.476345e-06
1.911991.5030431.509611e-06
1.921171.5029361.543037e-06
1.930391.5028271.576623e-06
1.939651.5027181.610370e-06
1.948961.5026071.644280e-06
1.958321.5024961.678352e-06
1.967721.5023841.712587e-06
1.971.5023571.720900e-06
1.977161.5022721.802127e-06
1.986651.5021581.909751e-06
1.996191.5020432.017893e-06
2.005771.5019272.126553e-06
2.01541.5018112.235735e-06
2.025071.5016932.345441e-06
2.034791.5015752.455673e-06
2.044561.5014562.566435e-06
2.054371.5013352.677728e-06
2.064231.5012142.789555e-06
2.074141.5010922.901920e-06
2.084091.5009683.014823e-06
2.09411.5008443.128268e-06
2.104151.5007183.242258e-06
2.114251.5005923.356795e-06
2.12441.5004643.471882e-06
2.134591.5003363.587521e-06
2.144841.5002063.703716e-06
2.155131.5000753.820467e-06
2.165481.4999433.937780e-06
2.175871.4998114.055655e-06
2.186321.4996764.174096e-06
2.196811.4995414.293106e-06
2.207351.4994054.412687e-06
2.217951.4992674.532842e-06
2.228591.4991284.653573e-06
2.239291.4989884.774885e-06
2.250041.4988474.896778e-06
2.260841.4987055.019256e-06
2.271691.4985615.142323e-06
2.282591.4984165.265980e-06
2.293551.498275.390230e-06
2.304561.4981235.515077e-06
2.315621.4979745.640523e-06
2.3251.4978475.746900e-06
2.326731.4978245.779811e-06
2.33791.4976735.991707e-06
2.349121.497526.204621e-06
2.36041.4973666.418556e-06
2.371731.497216.633518e-06
2.383111.4970546.849512e-06
2.394551.4968967.066543e-06
2.406041.4967367.284615e-06
2.417591.4965757.503734e-06
2.42921.4964137.723905e-06
2.440861.4962497.945132e-06
2.452571.4960838.167422e-06
2.464341.4959168.390778e-06
2.476171.4957488.615206e-06
2.488061.4955788.840712e-06
2.51.4954079.067300e-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
—