Optical constants

Refractive index of K7 (SCHOTT)

K7: n,k 0.31–2.5 µm

Data
formula 2 + tabulated k
Range
0.31–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.31–2.5 µm
Refractive index n
1.51112
Extinction coefficient k
1.08795e-08
Permittivity ε1
2.28348
Permittivity ε2
3.28803e-08
Absorption coefficient α
0.00232667 cm⁻¹
Penetration depth δ = λ/(2πk)
8.59596e+09 nm
Abbe number Vd
60.406
Chromatic dispersion dn/dλ
-0.0437407 µm⁻¹
Group index ng
1.53682
Group velocity dispersion
75.9717 fs²/mm
Dispersion parameter D
-414.466 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

# K7 (SCHOTT): K7
schott_k7 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "K7", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_k7.range_nm)  # (310, 2500) nm
eps = schott_k7.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=1.1273555λ2λ2−0.00720341707+0.124412303λ2λ2−0.0269835916+0.827100531λ2λ2−100.384588

Valid from 0.31 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.1273555
C30.00720341707
C40.124412303
C50.0269835916
C60.827100531
C7100.384588

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: -1.67e-06 8.8e-09 -2.86e-11 5.42e-07 7.81e-10 0.172
nd
1.51112
Vd
60.41
glass code
511604.253
glass status
standard
density
value: 2530
thermal expansion
value: 8.4e-06, temperature range: 243 343; value: 9.7e-06, temperature range: 293 573
resistance
acid: 2.0; stain: 0.0; alkali: 1.0; climatic: 3.0; phosphate: 2.3

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = -8.87e-08 K⁻¹ at 633 nm, dn/dT = -5.60e-07 K⁻¹ at 1310 nm, dn/dT = -5.96e-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 422 wavelengths, the same grid as the API and the library
K7 (SCHOTT), K7: n and k versus wavelength
λ (µm)nk
0.311.5462532.272100e-06
0.3116261.5456922.046321e-06
0.3132611.5451381.819358e-06
0.3149041.5445931.591205e-06
0.3165561.5440551.361855e-06
0.3182161.5435241.131301e-06
0.3198851.5430018.995386e-07
0.321.5429668.836300e-07
0.3215631.5424858.144529e-07
0.323251.5419777.398166e-07
0.3249461.5414756.647887e-07
0.326651.540985.893673e-07
0.3283641.5404925.135502e-07
0.3300861.540014.373355e-07
0.3318181.5395353.607209e-07
0.3335581.5390662.837045e-07
0.3341.5389492.641500e-07
0.3353081.5386042.481942e-07
0.3370671.5381482.267345e-07
0.3388351.5376982.051622e-07
0.3406121.5372531.834768e-07
0.3423991.5368151.616776e-07
0.3441951.5363821.397641e-07
0.3461.5359551.177356e-07
0.3478151.5355349.559162e-08
0.349641.5351187.333144e-08
0.351.5350376.893400e-08
0.3514741.5347086.552083e-08
0.3533171.5343026.125058e-08
0.3551711.5339025.695793e-08
0.3570341.5335085.264276e-08
0.3589061.5331184.830495e-08
0.3607891.5327334.394440e-08
0.3626821.5323533.956097e-08
0.3645841.5319783.515454e-08
0.3651.5318973.419100e-08
0.3664961.5316073.252100e-08
0.3684191.5312423.037555e-08
0.371.5309462.861100e-08
0.3703511.530882.833442e-08
0.3722941.5305242.680535e-08
0.3742471.5301722.526825e-08
0.376211.5298242.372309e-08
0.3781831.529482.216983e-08
0.381.5291692.074000e-08
0.3801671.5291412.064383e-08
0.3821611.5288061.949659e-08
0.3841661.5284751.834333e-08
0.3861811.5281481.718403e-08
0.3882071.5278251.601864e-08
0.391.5275441.498700e-08
0.3902431.5275061.493373e-08
0.392291.5271911.448524e-08
0.3943481.526881.403438e-08
0.3964161.5265721.358117e-08
0.3984961.5262681.312557e-08
0.41.5260521.279600e-08
0.4005861.5259681.281476e-08
0.4026871.5256711.288200e-08
0.40481.5253781.294959e-08
0.4051.5253511.295600e-08
0.4069231.5250891.301754e-08
0.4090581.5248031.308584e-08
0.4112031.524521.315450e-08
0.413361.524241.322353e-08
0.4155281.5239641.329291e-08
0.4177081.5236911.336266e-08
0.4198991.5234221.343277e-08
0.421.5234091.343600e-08
0.4221021.5231551.350326e-08
0.4243161.5228921.357411e-08
0.4265421.5226311.364533e-08
0.4287791.5223741.371693e-08
0.4310281.522121.378890e-08
0.4332891.5218681.386125e-08
0.4355621.521621.393398e-08
0.4361.5215721.394800e-08
0.4378471.5213741.400709e-08
0.4401431.5211311.408059e-08
0.4424521.5208911.415447e-08
0.4447731.5206541.422874e-08
0.4471061.5204191.430339e-08
0.4494511.5201871.437844e-08
0.4518091.5199571.445388e-08
0.4541791.5197311.452972e-08
0.4565611.5195061.460596e-08
0.4589561.5192851.468260e-08
0.461.5191891.471600e-08
0.4613641.5190651.459546e-08
0.4637841.5188481.438153e-08
0.4662161.5186341.416647e-08
0.4686621.5184221.395029e-08
0.471121.5182121.373297e-08
0.4735921.5180051.351451e-08
0.4760761.51781.329491e-08
0.4785731.5175971.307415e-08
0.4810831.5173961.285224e-08
0.4836071.5171981.262916e-08
0.4861441.5170011.240491e-08
0.4886941.5168071.217948e-08
0.4912571.5166151.195288e-08
0.4938341.5164251.172508e-08
0.4964241.5162371.149609e-08
0.4990281.5160511.126590e-08
0.51.5159821.118000e-08
0.5016461.5158671.115420e-08
0.5042771.5156851.111296e-08
0.5069221.5155051.107150e-08
0.5095821.5153271.102982e-08
0.5122551.5151511.098792e-08
0.5149421.5149761.094581e-08
0.5176431.5148041.090347e-08
0.5203581.5146331.086091e-08
0.5230871.5144641.081813e-08
0.5258311.5142961.077512e-08
0.528591.5141311.073189e-08
0.5313621.5139671.068843e-08
0.5341491.5138051.064474e-08
0.5369511.5136441.060083e-08
0.5397681.5134861.055668e-08
0.5425991.5133281.051230e-08
0.5454451.5131731.046769e-08
0.5461.5131431.045900e-08
0.5483071.5130191.050323e-08
0.5511831.5128661.055839e-08
0.5540741.5127151.061383e-08
0.556981.5125661.066956e-08
0.5599021.5124181.072559e-08
0.5628391.5122711.078191e-08
0.5657911.5121261.083853e-08
0.5687591.5119831.089544e-08
0.5717421.5118411.095265e-08
0.5747421.51171.101016e-08
0.5777561.511561.106797e-08
0.581.5114581.111100e-08
0.5807871.5114221.108703e-08
0.5838331.5112861.099421e-08
0.5868961.511151.090092e-08
0.5899741.5110161.080713e-08
0.5930691.5108831.071285e-08
0.596181.5107521.061807e-08
0.5993071.5106211.052280e-08
0.6024511.5104921.042703e-08
0.6056111.5103641.033076e-08
0.6087881.5102381.023398e-08
0.6119811.5101121.013669e-08
0.6151911.5099881.003890e-08
0.6184181.5098659.940586e-09
0.621.5098059.892400e-09
0.6216621.5097429.918937e-09
0.6249231.5096219.970998e-09
0.6282011.5095021.002333e-08
0.6314961.5093831.007594e-08
0.6348091.5092651.012882e-08
0.6381391.5091481.018198e-08
0.6414861.5090331.023542e-08
0.6448511.5089181.028915e-08
0.6482341.5088051.034315e-08
0.6516341.5086921.039743e-08
0.6550521.508581.045200e-08
0.6584881.508471.050686e-08
0.661.5084211.053100e-08
0.6619421.508361.045329e-08
0.6654141.5082511.031436e-08
0.6689051.5081431.017470e-08
0.6724131.5080361.003431e-08
0.6759411.507939.893180e-09
0.6794861.5078259.751310e-09
0.683051.5077219.608697e-09
0.6866331.5076179.465335e-09
0.6902351.5075159.321221e-09
0.6938561.5074139.176352e-09
0.6974951.5073129.030722e-09
0.71.5072438.930500e-09
0.7011541.5072128.966959e-09
0.7048321.5071129.083165e-09
0.7085291.5070149.199980e-09
0.7122461.5069169.317408e-09
0.7159821.5068199.435452e-09
0.7197371.5067229.554116e-09
0.7235131.5066279.673401e-09
0.7273081.5065329.793313e-09
0.7311231.5064379.913853e-09
0.7349581.5063441.003503e-08
0.7388131.5062511.015683e-08
0.7426891.5061591.027928e-08
0.7465841.5060671.040237e-08
0.7505011.5059771.052611e-08
0.7544371.5058861.065049e-08
0.7583951.5057971.077553e-08
0.7623731.5057081.090122e-08
0.7663721.5056191.102757e-08
0.7703921.5055321.115459e-08
0.7744331.5054441.128227e-08
0.7784951.5053581.141062e-08
0.7825791.5052721.153964e-08
0.7866841.5051861.166934e-08
0.790811.5051011.179972e-08
0.7949581.5050171.193079e-08
0.7991281.5049331.206254e-08
0.803321.5048491.219499e-08
0.8075341.5047661.232812e-08
0.811771.5046841.246196e-08
0.8160281.5046021.259650e-08
0.8203081.5045211.273174e-08
0.8246111.504441.286770e-08
0.8289371.5043591.300436e-08
0.8332851.5042791.314175e-08
0.8376561.5041991.327985e-08
0.842051.504121.341868e-08
0.8464671.5040411.355824e-08
0.8509071.5039631.369853e-08
0.855371.5038851.383955e-08
0.8598571.5038071.398132e-08
0.8643671.503731.412383e-08
0.8689011.5036531.426708e-08
0.8734591.5035761.441109e-08
0.8780411.50351.455585e-08
0.8826471.5034241.470138e-08
0.8872771.5033481.484766e-08
0.8919311.5032731.499471e-08
0.8966091.5031981.514254e-08
0.9013131.5031241.529114e-08
0.906041.5030491.544052e-08
0.9107931.5029751.559068e-08
0.9155711.5029011.574163e-08
0.9203731.5028281.589337e-08
0.9252011.5027551.604591e-08
0.9300541.5026821.619925e-08
0.9349331.5026091.635339e-08
0.9398371.5025361.650834e-08
0.9447671.5024641.666411e-08
0.9497221.5023921.682069e-08
0.9547041.502321.697809e-08
0.9597121.5022481.713632e-08
0.9647461.5021771.729538e-08
0.9698071.5021061.745527e-08
0.9748941.5020341.761600e-08
0.9800081.5019631.777757e-08
0.9851481.5018931.793999e-08
0.9903161.5018221.810327e-08
0.995511.5017511.826740e-08
1.000731.5016811.843239e-08
1.005981.5016111.859825e-08
1.011261.5015411.876497e-08
1.016561.5014711.893257e-08
1.02191.5014011.910105e-08
1.027261.5013311.927042e-08
1.032641.5012611.944067e-08
1.038061.5011911.961182e-08
1.043511.5011221.978386e-08
1.048981.5010521.995680e-08
1.054481.5009832.013066e-08
1.061.5009132.030500e-08
1.060011.5009132.030722e-08
1.065571.5008442.123099e-08
1.071161.5007742.215961e-08
1.076781.5007052.309310e-08
1.082431.5006352.403149e-08
1.088111.5005662.497480e-08
1.093821.5004972.592305e-08
1.099551.5004272.687629e-08
1.105321.5003582.783452e-08
1.111121.5002882.879778e-08
1.116951.5002192.976609e-08
1.122811.5001493.073948e-08
1.12871.500083.171797e-08
1.134621.500013.270160e-08
1.140571.499943.369039e-08
1.146551.4998713.468437e-08
1.152561.4998013.568356e-08
1.158611.4997313.668799e-08
1.164691.4996613.769768e-08
1.17081.499593.871268e-08
1.176941.499523.973300e-08
1.183111.4994494.075867e-08
1.189321.4993794.178972e-08
1.195561.4993084.282618e-08
1.201831.4992374.386808e-08
1.208131.4991664.491544e-08
1.214471.4990954.596830e-08
1.220841.4990234.702668e-08
1.227241.4989524.809061e-08
1.233681.498884.916012e-08
1.240151.4988085.023524e-08
1.246661.4987365.131600e-08
1.25321.4986635.240243e-08
1.259771.4985915.349456e-08
1.266381.4985185.459241e-08
1.273021.4984455.569603e-08
1.27971.4983715.680544e-08
1.286411.4982975.792066e-08
1.293161.4982245.904173e-08
1.299941.4981496.016869e-08
1.306761.4980756.130156e-08
1.313621.4986.244036e-08
1.320511.4979256.358515e-08
1.327431.4978496.473593e-08
1.33441.4977736.589276e-08
1.34141.4976976.705565e-08
1.348431.4976216.822464e-08
1.355511.4975446.939977e-08
1.362621.4974677.058105e-08
1.369761.4973897.176854e-08
1.376951.4973117.296225e-08
1.384171.4972337.416223e-08
1.391431.4971547.536849e-08
1.398731.4970757.658109e-08
1.406071.4969957.780005e-08
1.413441.4969157.902540e-08
1.420861.4968358.025718e-08
1.428311.4967548.149542e-08
1.43581.4966738.274015e-08
1.443331.4965918.399142e-08
1.45091.4965098.524925e-08
1.458521.4964268.651367e-08
1.466171.4963428.778473e-08
1.473861.4962598.906245e-08
1.481591.4961749.034688e-08
1.489361.4960899.163805e-08
1.497171.4960049.293599e-08
1.505031.4959189.424073e-08
1.512921.4958319.555232e-08
1.520861.4957449.687079e-08
1.528831.4956579.819618e-08
1.531.4956449.839000e-08
1.536851.4955681.198784e-07
1.544911.495481.451570e-07
1.553021.495391.705681e-07
1.561161.49531.961126e-07
1.569351.4952092.217910e-07
1.577591.4951182.476041e-07
1.585861.4950262.735527e-07
1.594181.4949332.996373e-07
1.602541.4948393.258588e-07
1.610951.4947453.522178e-07
1.61941.494653.787151e-07
1.627891.4945554.053513e-07
1.636431.4944584.321273e-07
1.645021.4943614.590437e-07
1.653641.4942644.861014e-07
1.662321.4941655.133009e-07
1.671041.4940665.406432e-07
1.67981.4939655.681288e-07
1.688611.4938645.957587e-07
1.697471.4937636.235334e-07
1.706381.493666.514539e-07
1.715331.4935576.795208e-07
1.724321.4934527.077349e-07
1.733371.4933477.360971e-07
1.742461.4932417.646080e-07
1.75161.4931347.932684e-07
1.760791.4930268.220792e-07
1.770031.4929178.510411e-07
1.779311.4928078.801550e-07
1.788641.4926969.094215e-07
1.798031.4925859.388416e-07
1.807461.4924729.684160e-07
1.816941.4923589.981455e-07
1.826471.4922441.028031e-06
1.836051.4921281.058073e-06
1.845681.4920111.088273e-06
1.855361.4918931.118631e-06
1.865091.4917741.149149e-06
1.874881.4916541.179826e-06
1.884711.4915331.210665e-06
1.89461.491411.241665e-06
1.904541.4912871.272828e-06
1.914531.4911621.304154e-06
1.924571.4910371.335645e-06
1.934671.490911.367301e-06
1.944811.4907811.399123e-06
1.955011.4906521.431111e-06
1.965271.4905211.463268e-06
1.971.4904611.478100e-06
1.975581.4903891.535485e-06
1.985941.4902561.642082e-06
1.996361.4901221.749239e-06
2.006831.4899861.856957e-06
2.017361.4898481.965241e-06
2.027941.489712.074092e-06
2.038581.489572.183514e-06
2.049271.4894292.293511e-06
2.060021.4892862.404084e-06
2.070831.4891422.515238e-06
2.081691.4889962.626974e-06
2.092611.4888492.739297e-06
2.103581.48872.852208e-06
2.114621.488552.965712e-06
2.125711.4883983.079812e-06
2.136861.4882453.194510e-06
2.148071.488093.309809e-06
2.159341.4879343.425714e-06
2.170661.4877763.542226e-06
2.182051.4876163.659350e-06
2.19351.4874553.777087e-06
2.2051.4872913.895443e-06
2.216571.4871274.014419e-06
2.22821.486964.134019e-06
2.239881.4867924.254247e-06
2.251631.4866224.375106e-06
2.263441.486454.496598e-06
2.275321.4862764.618728e-06
2.287251.48614.741498e-06
2.299251.4859224.864912e-06
2.311311.4857434.988974e-06
2.323431.4855615.113686e-06
2.3251.4855385.129800e-06
2.335621.4853785.339495e-06
2.347871.4851925.581380e-06
2.360191.4850055.824534e-06
2.372571.4848156.068964e-06
2.385011.4846246.314676e-06
2.397521.484436.561676e-06
2.41011.4842346.809973e-06
2.422741.4840367.059571e-06
2.435451.4838357.310479e-06
2.448231.4836337.562704e-06
2.461071.4834287.816251e-06
2.473981.4832218.071128e-06
2.486951.4830118.327342e-06
2.51.4827998.584900e-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
—