Optical constants

Refractive index of N-FK51 (SCHOTT)

N-FK51: n,k 0.29–2.5 µm

Data
formula 2 + tabulated k
Range
0.29–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.29–2.5 µm
Refractive index n
1.48656
Extinction coefficient k
5.99587e-09
Permittivity ε1
2.20986
Permittivity ε2
1.78264e-08
Absorption coefficient α
0.00128227 cm⁻¹
Penetration depth δ = λ/(2πk)
1.55973e+10 nm
Abbe number Vd
84.468
Chromatic dispersion dn/dλ
-0.0298601 µm⁻¹
Group index ng
1.50411
Group velocity dispersion
51.247 fs²/mm
Dispersion parameter D
-279.58 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

# N-FK51 (SCHOTT): N-FK51
schott_n_fk51 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-FK51", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_fk51.range_nm)  # (290, 2500) nm
eps = schott_n_fk51.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=0.971247817λ2λ2−0.00472301995+0.216901417λ2λ2−0.0153575612+0.904651666λ2λ2−168.68133

Valid from 0.29 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C20.971247817
C30.00472301995
C40.216901417
C50.0153575612
C60.904651666
C7168.68133

Comments and conditions

was replaced by N-FK51A

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: -1.83e-05 -7.89e-09 -1.63e-12 3.74e-07 3.46e-10 0.15
nd
1.48656
Vd
84.47
glass code
487845.366
glass status
preferred
density
value: 3660
thermal expansion
value: 1.33e-05, temperature range: 243 343; value: 1.549e-05, temperature range: 293 573
dPgF
0.0342
resistance
acid: 52.3; stain: 0.0; alkali: 2.2; climatic: 2.0; phosphate: 4.3

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = -7.03e-06 K⁻¹ at 633 nm, dn/dT = -7.24e-06 K⁻¹ at 1310 nm, dn/dT = -7.24e-06 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 424 wavelengths, the same grid as the API and the library
N-FK51 (SCHOTT), N-FK51: n and k versus wavelength
λ (µm)nk
0.291.5145784.251000e-06
0.291571.5141494.086206e-06
0.2931481.5137273.920519e-06
0.2947351.513313.753936e-06
0.2963311.5128983.586451e-06
0.2979351.5124923.418059e-06
0.2995481.5120923.248756e-06
0.31.5119813.201300e-06
0.301171.5116963.071589e-06
0.30281.5113062.890763e-06
0.3044391.5109212.708958e-06
0.3060871.5105412.526169e-06
0.3077441.5101652.342390e-06
0.309411.5097952.157617e-06
0.311.5096662.092200e-06
0.3110851.509431.998245e-06
0.3127691.5090691.852439e-06
0.3144621.5087121.705844e-06
0.3161651.5083611.558455e-06
0.3178761.5080141.410268e-06
0.3195971.5076711.261279e-06
0.321.5075921.226400e-06
0.3213271.5073331.156700e-06
0.3230671.5069991.065353e-06
0.3248161.5066699.735123e-07
0.3265741.5063438.811741e-07
0.3283421.5060217.883359e-07
0.330121.5057046.949952e-07
0.3319071.505396.011492e-07
0.3337031.5050815.067952e-07
0.3341.505034.912200e-07
0.335511.5047754.589032e-07
0.3373261.5044734.200290e-07
0.3391521.5041753.809444e-07
0.3409881.503883.416481e-07
0.3428341.503593.021392e-07
0.344691.5033022.624163e-07
0.3465561.5030192.224784e-07
0.3484321.5027381.823243e-07
0.351.5025081.487700e-07
0.3503191.5024621.465411e-07
0.3522151.5021881.332701e-07
0.3541221.5019181.199273e-07
0.3560391.5016511.065122e-07
0.3579661.5013889.302452e-08
0.3599041.5011287.946381e-08
0.3618521.500876.582968e-08
0.3638111.5006165.212175e-08
0.3651.5004644.380300e-08
0.3657811.5003654.143083e-08
0.3677611.5001173.541432e-08
0.3697521.4998722.936524e-08
0.371.4998422.861100e-08
0.3717531.499632.615481e-08
0.3737661.4993912.333571e-08
0.3757891.4991552.050135e-08
0.3778241.4989211.765165e-08
0.3798691.4986911.478652e-08
0.381.4986761.460300e-08
0.3819251.4984631.371119e-08
0.3839931.4982371.275354e-08
0.3860721.4980151.179070e-08
0.3881621.4977951.082265e-08
0.391.4976049.971200e-09
0.3902631.4975779.944181e-09
0.3923761.4973629.727165e-09
0.39451.497159.508974e-09
0.3966351.496949.289602e-09
0.3987831.4967339.069043e-09
0.41.4966178.944000e-09
0.4009411.4965288.965052e-09
0.4031121.4963259.013584e-09
0.4051.4961529.055800e-09
0.4052941.4961259.088799e-09
0.4074881.4959279.334856e-09
0.4096941.4957329.582245e-09
0.4119121.4955389.830973e-09
0.4141421.4953471.008105e-08
0.4163841.4951581.033248e-08
0.4186381.4949711.058527e-08
0.421.494861.073800e-08
0.4209041.4947871.076112e-08
0.4231831.4946041.081936e-08
0.4254741.4944241.087793e-08
0.4277771.4942451.093680e-08
0.4300931.4940691.099600e-08
0.4324211.4938951.105552e-08
0.4347621.4937221.111536e-08
0.4361.4936321.114700e-08
0.4371161.4935521.110697e-08
0.4394821.4933831.102208e-08
0.4418611.4932171.093673e-08
0.4442531.4930521.085091e-08
0.4466581.4928891.076464e-08
0.4490761.4927281.067789e-08
0.4515071.4925691.059068e-08
0.4539521.4924111.050299e-08
0.4564091.4922561.041483e-08
0.458881.4921011.032619e-08
0.461.4920321.028600e-08
0.4613641.4919491.015278e-08
0.4638621.4917999.908825e-09
0.4663731.491659.663551e-09
0.4688971.4915029.416950e-09
0.4714361.4913569.169013e-09
0.4739881.4912128.919735e-09
0.4765541.491078.669107e-09
0.4791341.4909298.417122e-09
0.4817271.4907898.163773e-09
0.4843351.4906517.909053e-09
0.4869571.4905157.652953e-09
0.4895931.490387.395467e-09
0.4922441.4902467.136588e-09
0.4949091.4901146.876307e-09
0.4975881.4899836.614617e-09
0.51.4898676.379000e-09
0.5002811.4898546.371920e-09
0.502991.4897266.303789e-09
0.5057131.48966.235289e-09
0.508451.4894746.166419e-09
0.5112031.489356.097175e-09
0.513971.4892286.027557e-09
0.5167531.4891075.957562e-09
0.519551.4889865.887188e-09
0.5223631.4888685.816433e-09
0.525191.488755.745295e-09
0.5280341.4886345.673772e-09
0.5308921.4885195.601862e-09
0.5337661.4884055.529562e-09
0.5366561.4882925.456871e-09
0.5395611.488185.383787e-09
0.5424821.488075.310306e-09
0.5454191.4879615.236428e-09
0.5461.4879395.221800e-09
0.5483711.4878535.244472e-09
0.551341.4877455.272857e-09
0.5543241.4876395.301396e-09
0.5573251.4875345.330090e-09
0.5603421.4874315.358938e-09
0.5633761.4873285.387943e-09
0.5664261.4872265.417105e-09
0.5694921.4871255.446425e-09
0.5725751.4870255.475903e-09
0.5756751.4869265.505541e-09
0.5787911.4868295.535340e-09
0.581.4867915.546900e-09
0.5819241.4867325.660576e-09
0.5850751.4866365.846677e-09
0.5882421.4865416.033786e-09
0.5914261.4864476.221907e-09
0.5946281.4863546.411047e-09
0.5978471.4862616.601211e-09
0.6010831.486176.792405e-09
0.6043371.4860796.984633e-09
0.6076091.485997.177902e-09
0.6108981.4859017.372217e-09
0.6142051.4858137.567584e-09
0.617531.4857267.764009e-09
0.621.4856627.909900e-09
0.6208731.4856397.967133e-09
0.6242351.4855548.187378e-09
0.6276141.4854698.408815e-09
0.6310111.4853858.631451e-09
0.6344271.4853028.855292e-09
0.6378621.485229.080345e-09
0.6413151.4851389.306616e-09
0.6447871.4850579.534112e-09
0.6482771.4849779.762840e-09
0.6517871.4848979.992806e-09
0.6553151.4848181.022402e-08
0.6588631.484741.045648e-08
0.661.4847151.053100e-08
0.662431.4846631.056975e-08
0.6660161.4845861.062695e-08
0.6696211.484511.068446e-08
0.6732461.4844341.074227e-08
0.6768911.484361.080041e-08
0.6805551.4842861.085885e-08
0.6842391.4842121.091762e-08
0.6879431.4841391.097670e-08
0.6916681.4840671.103610e-08
0.6954121.4839951.109582e-08
0.6991771.4839241.115587e-08
0.71.4839091.116900e-08
0.7029621.4838531.124416e-08
0.7067671.4837831.134073e-08
0.7105931.4837141.143783e-08
0.714441.4836451.153545e-08
0.7183081.4835771.163360e-08
0.7221961.4835091.173229e-08
0.7261061.4834421.183151e-08
0.7300361.4833751.193126e-08
0.7339891.4833091.203155e-08
0.7379621.4832431.213239e-08
0.7419571.4831781.223377e-08
0.7459741.4831131.233571e-08
0.7500121.4830491.243819e-08
0.7540721.4829851.254123e-08
0.7581541.4829221.264483e-08
0.7622591.4828591.274898e-08
0.7663851.4827961.285371e-08
0.7705341.4827341.295899e-08
0.7747051.4826731.306485e-08
0.7788991.4826121.317128e-08
0.7831161.4825511.327829e-08
0.7873551.4824911.338588e-08
0.7916171.4824311.349405e-08
0.7959031.4823711.360280e-08
0.8002111.4823121.371214e-08
0.8045431.4822531.382208e-08
0.8088991.4821951.393261e-08
0.8132781.4821371.404374e-08
0.817681.4820791.415547e-08
0.8221071.4820221.426780e-08
0.8265571.4819651.438075e-08
0.8310321.4819081.449430e-08
0.8355311.4818521.460847e-08
0.8400541.4817961.472326e-08
0.8446021.481741.483867e-08
0.8491741.4816841.495470e-08
0.8537711.4816291.507136e-08
0.8583931.4815741.518866e-08
0.863041.481521.530659e-08
0.8677121.4814661.542515e-08
0.8724091.4814121.554436e-08
0.8771321.4813581.566422e-08
0.881881.4813041.578472e-08
0.8866541.4812511.590587e-08
0.8914541.4811981.602769e-08
0.896281.4811451.615016e-08
0.9011321.4810931.627329e-08
0.9060111.4810411.639709e-08
0.9109151.4809891.652156e-08
0.9158461.4809371.664670e-08
0.9208041.4808851.677253e-08
0.9257891.4808341.689903e-08
0.9308011.4807821.702622e-08
0.935841.4807311.715409e-08
0.9409061.480681.728266e-08
0.9461.480631.741192e-08
0.9511211.4805791.754189e-08
0.956271.4805291.767256e-08
0.9614471.4804791.780393e-08
0.9666511.4804291.793602e-08
0.9718841.4803791.806882e-08
0.9771461.4803291.820234e-08
0.9824351.4802791.833658e-08
0.9877541.480231.847155e-08
0.9931011.480181.860725e-08
0.9984771.4801311.874369e-08
1.003881.4800821.888086e-08
1.009321.4800331.901878e-08
1.014781.4799841.915744e-08
1.020271.4799351.929685e-08
1.02581.4798861.943702e-08
1.031351.4798371.957795e-08
1.036931.4797881.971964e-08
1.042551.479741.986210e-08
1.048191.4796912.000532e-08
1.053871.4796432.014933e-08
1.059571.4795942.029411e-08
1.061.4795912.030500e-08
1.065311.4795462.118668e-08
1.071071.4794972.214481e-08
1.076871.4794492.310813e-08
1.08271.4794012.407666e-08
1.088561.4793532.505043e-08
1.094461.4793042.602947e-08
1.100381.4792562.701382e-08
1.106341.4792082.800349e-08
1.112331.4791592.899852e-08
1.118351.4791112.999894e-08
1.12441.4790633.100477e-08
1.130491.4790143.201605e-08
1.136611.4789663.303280e-08
1.142761.4789183.405506e-08
1.148951.4788693.508285e-08
1.155171.4788213.611621e-08
1.161421.4787723.715515e-08
1.167711.4787243.819973e-08
1.174031.4786753.924996e-08
1.180391.4786264.030587e-08
1.186781.4785774.136750e-08
1.19321.4785294.243488e-08
1.199661.478484.350803e-08
1.206161.478434.458700e-08
1.212681.4783814.567180e-08
1.219251.4783324.676248e-08
1.225851.4782834.785906e-08
1.232491.4782334.896158e-08
1.239161.4781835.007007e-08
1.245871.4781345.118456e-08
1.252611.4780845.230508e-08
1.259391.4780345.343167e-08
1.266211.4779845.456435e-08
1.273061.4779335.570317e-08
1.279961.4778835.684816e-08
1.286891.4778325.799934e-08
1.293851.4777815.915675e-08
1.300861.477736.032043e-08
1.30791.4776796.149041e-08
1.314981.4776286.266672e-08
1.32211.4775766.384940e-08
1.329251.4775246.503849e-08
1.336451.4774726.623401e-08
1.343691.477426.743600e-08
1.350961.4773676.864450e-08
1.358271.4773156.985954e-08
1.365631.4772627.108116e-08
1.373021.4772097.230939e-08
1.380451.4771557.354427e-08
1.387921.4771027.478584e-08
1.395441.4770487.603412e-08
1.402991.4769937.728917e-08
1.410591.4769397.855101e-08
1.418221.4768847.981968e-08
1.42591.4768298.109522e-08
1.433621.4767748.237766e-08
1.441381.4767188.366705e-08
1.449181.4766628.496341e-08
1.457031.4766068.626680e-08
1.464921.4765498.757723e-08
1.472851.4764928.889477e-08
1.480821.4764359.021944e-08
1.488841.4763779.155127e-08
1.49691.4763199.289032e-08
1.5051.4762619.423662e-08
1.513151.4762029.559020e-08
1.521341.4761439.695111e-08
1.529581.4760849.831939e-08
1.531.4760819.839000e-08
1.537861.4760241.035604e-07
1.546181.4759641.090401e-07
1.554551.4759031.145495e-07
1.562971.4758421.200886e-07
1.571431.475781.256578e-07
1.579931.4757181.312571e-07
1.588491.4756561.368867e-07
1.597091.4755931.425468e-07
1.605731.475531.482376e-07
1.614431.4754661.539591e-07
1.623161.4754021.597116e-07
1.631951.4753371.654953e-07
1.640791.4752721.713102e-07
1.649671.4752071.771567e-07
1.65861.475141.830348e-07
1.667581.4750741.889447e-07
1.676611.4750071.948866e-07
1.685681.4749392.008607e-07
1.694811.4748712.068671e-07
1.703981.4748022.129060e-07
1.713211.4747322.189777e-07
1.722481.4746632.250822e-07
1.731811.4745922.312197e-07
1.741181.4745212.373905e-07
1.750611.4744492.435946e-07
1.760081.4743772.498324e-07
1.769611.4743042.561039e-07
1.779191.4742312.624094e-07
1.788821.4741572.687490e-07
1.798511.4740822.751229e-07
1.808241.4740072.815314e-07
1.818031.473932.879745e-07
1.827871.4738542.944525e-07
1.837771.4737763.009656e-07
1.847721.4736983.075139e-07
1.857721.473623.140977e-07
1.867781.473543.207171e-07
1.877891.473463.273724e-07
1.888061.4733793.340637e-07
1.898281.4732973.407912e-07
1.908551.4732153.475551e-07
1.918881.4731323.543557e-07
1.929271.4730483.611931e-07
1.939721.4729633.680674e-07
1.950221.4728773.749790e-07
1.960771.4727913.819280e-07
1.971.4727153.880000e-07
1.971391.4727043.915320e-07
1.982061.4726164.186573e-07
1.992791.4725274.459294e-07
2.003581.4724384.733491e-07
2.014431.4723475.009173e-07
2.025331.4722565.286348e-07
2.03631.4721635.565022e-07
2.047321.472075.845206e-07
2.05841.4719766.126906e-07
2.069551.4718816.410131e-07
2.080751.4717856.694889e-07
2.092011.4716886.981189e-07
2.103341.471597.269039e-07
2.114721.4714917.558447e-07
2.126171.4713917.849422e-07
2.137681.471298.141972e-07
2.149251.4711898.436106e-07
2.160891.4710868.731832e-07
2.172591.4709829.029159e-07
2.184351.4708779.328095e-07
2.196171.470779.628650e-07
2.208061.4706639.930832e-07
2.220021.4705551.023465e-06
2.232031.4704451.054011e-06
2.244121.4703351.084723e-06
2.256271.4702231.115601e-06
2.268481.470111.146646e-06
2.280761.4699961.177859e-06
2.293111.4698811.209241e-06
2.305521.4697641.240793e-06
2.3181.4696461.272516e-06
2.3251.469581.290300e-06
2.330551.4695271.321991e-06
2.343171.4694071.394013e-06
2.355851.4692861.466425e-06
2.368611.4691631.539228e-06
2.381431.4690391.612426e-06
2.394321.4689131.686021e-06
2.407281.4687861.760013e-06
2.420311.4686581.834407e-06
2.433421.4685281.909203e-06
2.446591.4683971.984403e-06
2.459831.4682652.060011e-06
2.473151.4681312.136029e-06
2.486541.4679962.212457e-06
2.51.4678592.289300e-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
—