Optical constants

Refractive index of N-FK58 (SCHOTT)

N-FK58: n,k 0.26–2.5 µm

Data
formula 2 + tabulated k
Range
0.26–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.26–2.5 µm
Refractive index n
1.456
Extinction coefficient k
1.12565e-08
Permittivity ε1
2.11993
Permittivity ε2
3.27790e-08
Absorption coefficient α
0.00240732 cm⁻¹
Penetration depth δ = λ/(2πk)
8.30801e+09 nm
Abbe number Vd
90.9
Chromatic dispersion dn/dλ
-0.0260196 µm⁻¹
Group index ng
1.47129
Group velocity dispersion
44.4954 fs²/mm
Dispersion parameter D
-242.746 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-FK58 (SCHOTT): N-FK58
schott_n_fk58 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-FK58", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_fk58.range_nm)  # (260, 2500) nm
eps = schott_n_fk58.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=0.738042712λ2λ2−0.00339065607+0.363371967λ2λ2−0.0117551189+0.989296264λ2λ2−212.842145

Valid from 0.26 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C20.738042712
C30.00339065607
C40.363371967
C50.0117551189
C60.989296264
C7212.842145

Comments and conditions

XLD glass

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: -2.05e-05 -6.33e-09 4.13e-11 3.84e-07 1.63e-10 0.073
nd
1.456
Vd
90.9
glass code
456909.365
glass status
standard
density
value: 3646
thermal expansion
value: 1.367e-05, temperature range: 243 343; value: 1.572e-05, temperature range: 293 573
dPgF
0.0438
resistance
acid: 52.3; stain: 1.0; alkali: 3.3; climatic: 1.0; phosphate: 4.3

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = -7.50e-06 K⁻¹ at 633 nm, dn/dT = -7.68e-06 K⁻¹ at 1310 nm, dn/dT = -7.68e-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 427 wavelengths, the same grid as the API and the library
N-FK58 (SCHOTT), N-FK58: n and k versus wavelength
λ (µm)nk
0.261.4888124.384900e-06
0.2614791.4883064.321744e-06
0.2629671.4878064.258229e-06
0.2644621.4873144.194352e-06
0.2659671.4868294.130112e-06
0.267481.4863514.065506e-06
0.2690021.485884.000533e-06
0.271.4855763.957900e-06
0.2705321.4854153.916890e-06
0.2720711.4849583.798220e-06
0.2736191.4845063.678874e-06
0.2751751.4840613.558849e-06
0.276741.4836223.438142e-06
0.2783151.483193.316748e-06
0.2798981.4827633.194663e-06
0.281.4827363.186800e-06
0.281491.4823423.059336e-06
0.2830921.4819272.922376e-06
0.2847021.4815182.784636e-06
0.2863221.4811152.646112e-06
0.287951.4807172.506801e-06
0.2895881.4803252.366697e-06
0.291.4802272.331500e-06
0.2912361.4799382.233298e-06
0.2928931.4795562.101652e-06
0.2945591.4791791.969257e-06
0.2962341.4788081.836109e-06
0.297921.4784421.702204e-06
0.2996141.478081.567537e-06
0.31.4779991.536900e-06
0.3013191.4777241.453451e-06
0.3030331.4773721.344992e-06
0.3047571.4770251.235916e-06
0.3064911.4766831.126219e-06
0.3082341.4763451.015899e-06
0.3099881.4760129.049505e-07
0.311.4760099.041600e-07
0.3117511.4756838.340052e-07
0.3135241.4753587.629480e-07
0.3153081.4750386.914865e-07
0.3171021.4747226.196184e-07
0.3189061.474415.473416e-07
0.321.4742245.034900e-07
0.320721.4741034.877906e-07
0.3225441.4737994.479922e-07
0.3243791.4734994.079673e-07
0.3262241.4732043.677147e-07
0.328081.4729123.272332e-07
0.3299461.4726242.865214e-07
0.3318231.4723392.455779e-07
0.3337111.4720592.044016e-07
0.3341.4720161.981000e-07
0.335611.4717821.851067e-07
0.3375191.4715081.696941e-07
0.3394391.4712381.541938e-07
0.341371.4709721.386053e-07
0.3433121.4707081.229281e-07
0.3452651.4704491.071618e-07
0.3472291.4701929.130579e-08
0.3492041.4699397.535956e-08
0.351.4698386.893400e-08
0.3511911.4696896.579731e-08
0.3531881.4694426.053384e-08
0.3551981.4691995.524044e-08
0.3572181.4689584.991692e-08
0.359251.4687214.456312e-08
0.3612941.4684863.917887e-08
0.3633491.4682553.376398e-08
0.3651.4680722.941500e-08
0.3654161.4680262.894703e-08
0.3674951.46782.661010e-08
0.3695861.4675772.425988e-08
0.371.4675332.379400e-08
0.3716881.4673572.244929e-08
0.3738021.4671392.076494e-08
0.3759291.4669241.907101e-08
0.3780671.4667121.736744e-08
0.381.4665241.582800e-08
0.3802181.4665031.575488e-08
0.3823811.4662961.503007e-08
0.3845561.4660911.430114e-08
0.3867441.4658891.356807e-08
0.3889441.465691.283082e-08
0.391.4655961.247700e-08
0.3911571.4654931.236526e-08
0.3933821.4652991.215031e-08
0.395621.4651061.193413e-08
0.397871.4649161.171673e-08
0.41.464741.151100e-08
0.4001341.4647291.151485e-08
0.402411.4645441.158041e-08
0.4046991.4643611.164633e-08
0.4051.4643371.165500e-08
0.4070011.464181.171264e-08
0.4093171.4640011.177932e-08
0.4116451.4638251.184638e-08
0.4139871.463651.191382e-08
0.4163421.4634781.198165e-08
0.418711.4633081.204986e-08
0.421.4632161.208700e-08
0.4210921.463141.211840e-08
0.4234881.4629731.218727e-08
0.4258971.4628091.225653e-08
0.428321.4626471.232619e-08
0.4307561.4624861.239624e-08
0.4332071.4623281.246669e-08
0.4356711.4621711.253754e-08
0.4361.4621511.254700e-08
0.4381491.4620171.247660e-08
0.4406421.4618641.239497e-08
0.4431491.4617131.231288e-08
0.445671.4615631.223032e-08
0.4482051.4614161.214729e-08
0.4507551.461271.206379e-08
0.4533191.4611251.197981e-08
0.4558981.4609831.189535e-08
0.4584911.4608421.181042e-08
0.461.4607611.176100e-08
0.4610991.4607031.170101e-08
0.4637221.4605651.155786e-08
0.466361.4604291.141390e-08
0.4690131.4602941.126912e-08
0.4716811.4601611.112351e-08
0.4743651.460031.097708e-08
0.4770631.45991.082982e-08
0.4797771.4597721.068171e-08
0.4825061.4596441.053277e-08
0.4852511.4595191.038298e-08
0.4880121.4593951.023233e-08
0.4907881.4592721.008083e-08
0.493581.459159.928466e-09
0.4963881.459039.775235e-09
0.4992111.4589129.621133e-09
0.51.4588799.578100e-09
0.5020511.4587949.539464e-09
0.5049071.4586789.485671e-09
0.507781.4585639.431573e-09
0.5106681.458459.377166e-09
0.5135731.4583389.322450e-09
0.5164951.4582279.267423e-09
0.5194331.4581179.212083e-09
0.5223881.4580089.156428e-09
0.525361.4579019.100456e-09
0.5283481.4577949.044166e-09
0.5313541.4576898.987556e-09
0.5343771.4575858.930624e-09
0.5374171.4574828.873368e-09
0.5404741.4573818.815786e-09
0.5435481.457288.757876e-09
0.5461.4572018.711700e-09
0.546641.457188.756894e-09
0.549751.4570828.976337e-09
0.5528771.4569849.197028e-09
0.5560231.4568889.418974e-09
0.5591861.4567929.642183e-09
0.5623671.4566989.866662e-09
0.5655661.4566041.009242e-08
0.5687831.4565121.031946e-08
0.5720191.456421.054779e-08
0.5752731.456331.077742e-08
0.5785451.456241.100836e-08
0.581.4562011.111100e-08
0.5818371.4561511.114617e-08
0.5851471.4560641.120956e-08
0.5884751.4559771.127330e-08
0.5918231.4558911.133741e-08
0.595191.4558051.140188e-08
0.5985761.4557211.146672e-08
0.6019811.4556381.153193e-08
0.6054051.4555551.159751e-08
0.6088491.4554731.166346e-08
0.6123131.4553921.172979e-08
0.6157961.4553121.179649e-08
0.6192991.4552321.186358e-08
0.621.4552171.187700e-08
0.6228221.4551541.208026e-08
0.6263651.4550761.233545e-08
0.6299281.4549991.259209e-08
0.6335121.4549221.285019e-08
0.6371161.4548461.310976e-08
0.640741.4547711.337080e-08
0.6443851.4546971.363333e-08
0.6480511.4546241.389736e-08
0.6517371.4545511.416288e-08
0.6554451.4544781.442992e-08
0.6591741.4544071.469847e-08
0.661.4543911.475800e-08
0.6629231.4543361.482334e-08
0.6666951.4542661.490762e-08
0.6704871.4541961.499239e-08
0.6743011.4541271.507764e-08
0.6781371.4540591.516337e-08
0.6819951.4539911.524959e-08
0.6858751.4539241.533630e-08
0.6897761.4538571.542350e-08
0.69371.4537911.551120e-08
0.6976471.4537261.559940e-08
0.71.4536871.565200e-08
0.7016151.4536611.565766e-08
0.7056071.4535961.567164e-08
0.7096211.4535331.568570e-08
0.7136571.4534691.569984e-08
0.7177171.4534071.571406e-08
0.72181.4533441.572836e-08
0.7259061.4532831.574274e-08
0.7300361.4532211.575721e-08
0.7341891.4531611.577176e-08
0.7383651.45311.578638e-08
0.7425661.4530411.580110e-08
0.746791.4529811.581589e-08
0.7510381.4529221.583078e-08
0.7553111.4528641.584574e-08
0.7596071.4528061.586079e-08
0.7639281.4527481.587593e-08
0.7682741.4526911.589115e-08
0.7726451.4526341.590646e-08
0.777041.4525781.592185e-08
0.781461.4525221.593734e-08
0.7859061.4524671.595291e-08
0.7903771.4524111.596857e-08
0.7948731.4523571.598432e-08
0.7993951.4523021.600016e-08
0.8039421.4522481.601609e-08
0.8085161.4521951.603211e-08
0.8131151.4521411.604822e-08
0.8177411.4520881.606442e-08
0.8223931.4520361.608071e-08
0.8270711.4519831.609710e-08
0.8317761.4519311.611358e-08
0.8365081.4518791.613016e-08
0.8412661.4518281.614682e-08
0.8460521.4517771.616359e-08
0.8508651.4517261.618045e-08
0.8557051.4516751.619740e-08
0.8605731.4516251.621445e-08
0.8654691.4515751.623160e-08
0.8703921.4515251.624885e-08
0.8753441.4514761.626619e-08
0.8803231.4514271.628363e-08
0.8853311.4513781.630117e-08
0.8903671.4513291.631881e-08
0.8954321.451281.633656e-08
0.9005261.4512321.635440e-08
0.9056491.4511841.637234e-08
0.9108011.4511361.639039e-08
0.9159821.4510881.640854e-08
0.9211931.4510411.642679e-08
0.9264341.4509941.644515e-08
0.9317041.4509461.646361e-08
0.9370041.45091.648217e-08
0.9423341.4508531.650084e-08
0.9476951.4508061.651962e-08
0.9530861.450761.653850e-08
0.9585081.4507131.655750e-08
0.9639611.4506671.657660e-08
0.9694441.4506211.659580e-08
0.9749591.4505751.661512e-08
0.9805061.450531.663455e-08
0.9860831.4504841.665409e-08
0.9916931.4504381.667374e-08
0.9973341.4503931.669350e-08
1.003011.4503481.671337e-08
1.008711.4503021.673336e-08
1.014451.4502571.675346e-08
1.020221.4502121.677367e-08
1.026031.4501671.679400e-08
1.031861.4501221.681444e-08
1.037731.4500781.683501e-08
1.043641.4500331.685568e-08
1.049571.4499881.687648e-08
1.055541.4499441.689739e-08
1.061.449911.691300e-08
1.061551.4498991.688939e-08
1.067591.4498541.679736e-08
1.073661.449811.670480e-08
1.079771.4497651.661171e-08
1.085911.4497211.651810e-08
1.092091.4496761.642395e-08
1.09831.4496321.632927e-08
1.104551.4495871.623405e-08
1.110831.4495431.613829e-08
1.117151.4494981.604198e-08
1.123511.4494541.594512e-08
1.12991.4494091.584772e-08
1.136331.4493651.574976e-08
1.142791.449321.565124e-08
1.149291.4492751.555216e-08
1.155831.4492311.545252e-08
1.16241.4491861.535231e-08
1.169021.4491411.525153e-08
1.175671.4490961.515018e-08
1.182361.4490511.504825e-08
1.189081.4490061.494574e-08
1.195851.4489611.484265e-08
1.202651.4489161.473897e-08
1.209491.4488711.463471e-08
1.216371.4488251.452985e-08
1.223291.448781.442439e-08
1.230251.4487341.431833e-08
1.237251.4486891.421167e-08
1.244291.4486431.410440e-08
1.251361.4485971.399653e-08
1.258481.4485511.388803e-08
1.265641.4485041.377893e-08
1.272841.4484581.366920e-08
1.280081.4484111.355884e-08
1.287361.4483651.344786e-08
1.294691.4483181.333625e-08
1.302051.4482711.322400e-08
1.309461.4482231.311112e-08
1.316911.4481761.299759e-08
1.32441.4481281.288341e-08
1.331941.448081.276859e-08
1.339511.4480321.265311e-08
1.347131.4479841.253698e-08
1.35481.4479361.242019e-08
1.36251.4478871.230273e-08
1.370251.4478381.218460e-08
1.378051.4477891.206580e-08
1.385891.4477391.194633e-08
1.393771.447691.182617e-08
1.40171.447641.170534e-08
1.409671.4475891.158381e-08
1.417691.4475391.146159e-08
1.425761.4474881.133868e-08
1.433871.4474371.121507e-08
1.442031.4473861.109076e-08
1.450231.4473341.096574e-08
1.458481.4472821.084000e-08
1.466781.447231.071356e-08
1.475121.4471771.058639e-08
1.483511.4471241.045850e-08
1.491951.4470711.032988e-08
1.500441.4470171.020053e-08
1.508971.4469631.007044e-08
1.517561.4469099.939618e-09
1.526191.4468549.808048e-09
1.531.446839.750000e-09
1.534871.4467999.781056e-09
1.54361.4467449.836699e-09
1.552391.4466889.892659e-09
1.561221.4466329.948937e-09
1.57011.4465751.000553e-08
1.579031.4465181.006245e-08
1.588011.4464611.011970e-08
1.597051.4464031.017727e-08
1.606131.4463441.023517e-08
1.615271.4462861.029339e-08
1.624461.4462261.035195e-08
1.63371.4461671.041084e-08
1.642991.4461061.047007e-08
1.652341.4460461.052963e-08
1.661741.4459851.058953e-08
1.671191.4459231.064977e-08
1.68071.4458611.071036e-08
1.690261.4457981.077129e-08
1.699871.4457351.083256e-08
1.709541.4456721.089419e-08
1.719271.4456071.095616e-08
1.729051.4455431.101849e-08
1.738891.4454771.108118e-08
1.748781.4454111.114421e-08
1.758731.4453451.120761e-08
1.768731.4452781.127137e-08
1.778791.445211.133549e-08
1.788911.4451421.139998e-08
1.799091.4450731.146483e-08
1.809321.4450041.153005e-08
1.819621.4449341.159564e-08
1.829971.4448631.166161e-08
1.840381.4447911.172795e-08
1.850851.4447191.179467e-08
1.861381.4446471.186177e-08
1.871961.4445731.192925e-08
1.882611.4444991.199711e-08
1.893321.4444241.206536e-08
1.904091.4443491.213400e-08
1.914931.4442731.220303e-08
1.925821.4441961.227245e-08
1.936771.4441181.234226e-08
1.947791.444041.241248e-08
1.958871.443961.248309e-08
1.971.443881.255400e-08
1.970021.443881.255479e-08
1.981221.4437991.309486e-08
1.992491.4437181.363801e-08
2.003831.4436351.418425e-08
2.015231.4435521.473360e-08
2.026691.4434681.528607e-08
2.038221.4433831.584168e-08
2.049821.4432971.640045e-08
2.061481.4432111.696241e-08
2.07321.4431231.752756e-08
2.0851.4430351.809592e-08
2.096861.4429451.866752e-08
2.108791.4428551.924237e-08
2.120781.4427641.982049e-08
2.132851.4426712.040189e-08
2.144981.4425782.098661e-08
2.157181.4424842.157465e-08
2.169451.4423892.216604e-08
2.18181.4422932.276079e-08
2.194211.4421962.335893e-08
2.206691.4420972.396046e-08
2.219241.4419982.456542e-08
2.231871.4418982.517382e-08
2.244561.4417962.578568e-08
2.257331.4416942.640103e-08
2.270171.441592.701987e-08
2.283091.4414852.764223e-08
2.296081.441382.826814e-08
2.309141.4412732.889760e-08
2.322271.4411642.953065e-08
2.3251.4411422.966200e-08
2.335491.4410553.123405e-08
2.348771.4409443.322602e-08
2.362131.4408323.522933e-08
2.375571.4407193.724403e-08
2.389081.4406053.927019e-08
2.402671.4404894.130788e-08
2.416341.4403724.335716e-08
2.430091.4402544.541810e-08
2.443911.4401354.749077e-08
2.457821.4400144.957522e-08
2.47181.4398915.167153e-08
2.485861.4397685.377977e-08
2.51.4396435.590000e-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
—