Optical constants

Refractive index of K-LaFK50T (SUMITA)

K-LaFK50T: 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
1.766
Extinction coefficient k
1.87414e-08
Permittivity ε1
3.11874
Permittivity ε2
6.61946e-08
Absorption coefficient α
0.00400803 cm⁻¹
Penetration depth δ = λ/(2πk)
4.98998e+09 nm
Abbe number Vd
49.798
Chromatic dispersion dn/dλ
-0.0789829 µm⁻¹
Group index ng
1.81241
Group velocity dispersion
144.197 fs²/mm
Dispersion parameter D
-786.671 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-LaFK50T (SUMITA): K-LaFK50T
sumita_k_lafk50t = ls.fetch_refractiveindex("specs", "SUMITA-optical", "K-LaFK50T", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(sumita_k_lafk50t.range_nm)  # (360, 1550) nm
eps = sumita_k_lafk50t.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=3.0499602−0.012620328⁢λ2.0+0.023782461⁢λ−2.0+0.00047558583⁢λ−4.0+1.3668355×10-5⁢λ−6.0−8.9484311×10-7⁢λ−8.0

Valid from 0.36 to 1.55 µm.

Coefficients as stored
CiValue
C13.0499602
C2-0.012620328
C32.0
C40.023782461
C5-2.0
C60.00047558583
C7-4.0
C81.3668355e-05
C9-6.0
C10-8.9484311e-07
C11-8.0

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 2.67e-06 1.57e-08 -3.04e-10 6.28e-07 3.17e-10 0.192
nd
1.76600
Vd
49.8
glass code
766498
density
value: 4750
thermal expansion
value: 6.3e-06, temperature range: 243 343; value: 8.1e-06, temperature range: 293 573
dPgF
-0.0064
resistance
acid: 3.0; climatic: 1.0

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = 2.63e-06 K⁻¹ at 633 nm, dn/dT = 1.78e-06 K⁻¹ at 1310 nm, dn/dT = 1.71e-06 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-LaFK50T (SUMITA), K-LaFK50T: n and k versus wavelength
λ (µm)nk
0.361.8064482.638900e-07
0.361321.8059482.502253e-07
0.3626441.8054522.365106e-07
0.3639731.8049612.227455e-07
0.3653081.8044732.089300e-07
0.3666471.803991.950639e-07
0.3679911.8035111.811469e-07
0.369341.8030361.671789e-07
0.371.8028061.603400e-07
0.3706931.8025661.558249e-07
0.3720521.8020991.469771e-07
0.3734161.8016361.380969e-07
0.3747851.8011771.291841e-07
0.3761591.8007221.202386e-07
0.3775371.8002711.112603e-07
0.3789211.7998241.022492e-07
0.381.7994799.522600e-08
0.380311.7993819.382405e-08
0.3817041.7989418.752731e-08
0.3831041.7985058.120749e-08
0.3845081.7980737.486450e-08
0.3859171.7976456.849826e-08
0.3873321.797226.210868e-08
0.3887521.7967995.569569e-08
0.391.7964335.005800e-08
0.3901771.7963814.979537e-08
0.3916071.7959674.767147e-08
0.3930431.7955574.553978e-08
0.3944831.795154.340027e-08
0.3959291.7947464.125293e-08
0.3973811.7943463.909771e-08
0.3988371.7939493.693460e-08
0.41.7936363.520800e-08
0.4002991.7935563.493183e-08
0.4017671.7931663.357784e-08
0.4032391.7927793.221888e-08
0.4047171.7923963.085495e-08
0.4062011.7920152.948601e-08
0.407691.7916382.811206e-08
0.4091841.7912642.673307e-08
0.4106841.7908942.534903e-08
0.412191.7905262.395991e-08
0.4137011.7901622.256570e-08
0.4152171.78982.116638e-08
0.4167391.7894421.976193e-08
0.4182671.7890861.835233e-08
0.41981.7887341.693757e-08
0.421.7886881.675300e-08
0.4213391.7883841.657099e-08
0.4228831.7880381.636102e-08
0.4244331.7876941.615028e-08
0.4259891.7873531.593877e-08
0.4275511.7870151.572648e-08
0.4291181.786681.551341e-08
0.4306911.7863481.529957e-08
0.432271.7860181.508494e-08
0.4338541.7856911.486952e-08
0.4354451.7853671.465331e-08
0.4370411.7850451.443631e-08
0.4386431.7847271.421852e-08
0.441.7844591.403400e-08
0.4402511.784411.404200e-08
0.4418641.7840971.409348e-08
0.4434841.7837861.414514e-08
0.445111.7834771.419700e-08
0.4467411.7831721.424905e-08
0.4483791.7828681.430129e-08
0.4500231.7825671.435372e-08
0.4516721.7822691.440634e-08
0.4533281.7819731.445916e-08
0.454991.7816791.451217e-08
0.4566571.7813881.456537e-08
0.4583311.7810991.461877e-08
0.461.7808151.467200e-08
0.4600111.7808131.467236e-08
0.4616981.7805291.472615e-08
0.463391.7802471.478014e-08
0.4650891.7799671.483433e-08
0.4667931.779691.488871e-08
0.4685051.7794151.494329e-08
0.4702221.7791421.499808e-08
0.4719461.7788721.505306e-08
0.4736751.7786031.510825e-08
0.4754121.7783371.516364e-08
0.4771541.7780731.521923e-08
0.4789041.7778111.527502e-08
0.481.7776481.531000e-08
0.4806591.7775511.533099e-08
0.4824211.7772931.538711e-08
0.4841891.7770381.544343e-08
0.4859641.7767841.549996e-08
0.4877461.7765321.555669e-08
0.4895331.7762831.561364e-08
0.4913281.7760351.567079e-08
0.4931291.7757891.572815e-08
0.4949361.7755461.578573e-08
0.4967511.7753041.584351e-08
0.4985721.7750641.590151e-08
0.51.7748771.594700e-08
0.5003991.7748261.595973e-08
0.5022331.774591.601825e-08
0.5040741.7743551.607698e-08
0.5059221.7741231.613592e-08
0.5077771.7738921.619508e-08
0.5096381.7736631.625445e-08
0.5115061.7734361.631405e-08
0.5133811.7732111.637386e-08
0.5152631.7729871.643389e-08
0.5171521.7727661.649414e-08
0.5190471.7725461.655461e-08
0.520951.7723271.661531e-08
0.522861.772111.667622e-08
0.5247761.7718951.673736e-08
0.52671.7716821.679873e-08
0.5286311.771471.686032e-08
0.5305681.771261.692213e-08
0.5325131.7710521.698417e-08
0.5344651.7708451.704644e-08
0.5364241.770641.710894e-08
0.5383911.7704361.717166e-08
0.5403641.7702341.723462e-08
0.5423451.7700331.729780e-08
0.5443331.7698341.736122e-08
0.5463281.7696361.742487e-08
0.5483311.769441.748876e-08
0.551.7692791.754200e-08
0.5503411.7692461.755287e-08
0.5523581.7690521.761723e-08
0.5543831.7688611.768182e-08
0.5564151.768671.774664e-08
0.5584551.7684821.781171e-08
0.5605021.7682941.787701e-08
0.5625561.7681081.794255e-08
0.5646191.7679231.800833e-08
0.5666881.767741.807435e-08
0.5687651.7675581.814062e-08
0.570851.7673781.820713e-08
0.5729431.7671981.827388e-08
0.5750431.767021.834087e-08
0.5771511.7668441.840811e-08
0.5792671.7666681.847560e-08
0.581391.7664941.854334e-08
0.5835211.7663211.861132e-08
0.585661.766151.867955e-08
0.5878071.7659791.874804e-08
0.5899611.765811.881677e-08
0.5921241.7656431.888576e-08
0.5942951.7654761.895500e-08
0.5964731.765311.902449e-08
0.5986591.7651461.909424e-08
0.61.7650461.913700e-08
0.6008541.7649831.916424e-08
0.6030561.7648211.923450e-08
0.6052671.764661.930502e-08
0.6074861.7645011.937579e-08
0.6097121.7643421.944683e-08
0.6119471.7641851.951812e-08
0.6141911.7640291.958968e-08
0.6164421.7638731.966150e-08
0.6187021.7637191.973358e-08
0.620971.7635661.980593e-08
0.6232461.7634141.987854e-08
0.625531.7632631.995142e-08
0.6278231.7631142.002456e-08
0.6301251.7629652.009798e-08
0.6324341.7628172.017166e-08
0.6347531.762672.024561e-08
0.6370791.7625252.031984e-08
0.6394151.762382.039433e-08
0.6417591.7622362.046910e-08
0.6441111.7620932.054414e-08
0.6464721.7619512.061946e-08
0.6488421.761812.069505e-08
0.651.7617422.073200e-08
0.651221.7616712.077090e-08
0.6536071.7615322.084700e-08
0.6560031.7613932.092338e-08
0.6584081.7612562.100004e-08
0.6608211.761122.107698e-08
0.6632441.7609852.115421e-08
0.6656751.760852.123171e-08
0.6681151.7607172.130951e-08
0.6705641.7605842.138758e-08
0.6730221.7604522.146594e-08
0.6754891.7603212.154459e-08
0.6779651.7601912.162353e-08
0.680451.7600622.170276e-08
0.6829451.7599342.178227e-08
0.6854481.7598062.186208e-08
0.6879611.7596792.194218e-08
0.6904821.7595532.202258e-08
0.6930131.7594282.210327e-08
0.6955541.7593042.218425e-08
0.6981031.759182.226554e-08
0.71.7590892.232600e-08
0.7006621.7590572.234713e-08
0.7032311.7589352.242906e-08
0.7058091.7588142.251129e-08
0.7083961.7586932.259382e-08
0.7109921.7585732.267666e-08
0.7135991.7584542.275980e-08
0.7162141.7583362.284324e-08
0.718841.7582182.292699e-08
0.7214751.7581012.301105e-08
0.7241191.7579852.309541e-08
0.7267741.757872.318008e-08
0.7294381.7577552.326507e-08
0.7321121.7576412.335036e-08
0.7347951.7575272.343597e-08
0.7374891.7574142.352189e-08
0.7401921.7573022.360813e-08
0.7429051.7571912.369468e-08
0.7456291.757082.378155e-08
0.7483621.756972.386874e-08
0.7511051.756862.395625e-08
0.7538581.7567512.404408e-08
0.7566221.7566432.413223e-08
0.7593951.7565352.422070e-08
0.7621791.7564282.430950e-08
0.7649731.7563222.439863e-08
0.7677771.7562162.448808e-08
0.7705911.756112.457786e-08
0.7734161.7560062.466796e-08
0.7762511.7559012.475840e-08
0.7790961.7557982.484917e-08
0.7819521.7556952.494027e-08
0.7848181.7555922.503171e-08
0.7876951.755492.512348e-08
0.7905831.7553892.521559e-08
0.7934811.7552882.530803e-08
0.7963891.7551882.540082e-08
0.7993091.7550882.549394e-08
0.81.7550642.551600e-08
0.8022381.7549892.558740e-08
0.8051791.754892.568120e-08
0.8081311.7547922.577534e-08
0.8110931.7546942.586982e-08
0.8140661.7545972.596465e-08
0.817051.75452.605983e-08
0.8200451.7544032.615536e-08
0.8230511.7543082.625124e-08
0.8260681.7542122.634747e-08
0.8290961.7541172.644406e-08
0.8321351.7540232.654099e-08
0.8351861.7539292.663828e-08
0.8382471.7538352.673593e-08
0.841321.7537422.683394e-08
0.8444041.7536492.693231e-08
0.8474991.7535572.703103e-08
0.8506061.7534652.713012e-08
0.8537241.7533742.722957e-08
0.8568531.7532832.732939e-08
0.8599941.7531922.742957e-08
0.8631461.7531022.753012e-08
0.866311.7530122.763104e-08
0.8694861.7529232.773233e-08
0.8726731.7528342.783399e-08
0.8758721.7527452.793602e-08
0.8790821.7526572.803843e-08
0.8823051.7525692.814121e-08
0.8855391.7524812.824437e-08
0.8887851.7523942.834790e-08
0.8920431.7523072.845182e-08
0.8953131.7522212.855612e-08
0.8985951.7521352.866080e-08
0.9018891.7520492.876586e-08
0.9051951.7519632.887131e-08
0.9085131.7518782.897714e-08
0.9118431.7517932.908336e-08
0.9151861.7517092.918997e-08
0.918541.7516252.929698e-08
0.9219071.7515412.940437e-08
0.9252871.7514572.951216e-08
0.9286781.7513742.962034e-08
0.9320831.7512912.972892e-08
0.9354991.7512082.983790e-08
0.9389281.7511262.994728e-08
0.942371.7510443.005706e-08
0.9458241.7509623.016724e-08
0.9492911.750883.027782e-08
0.9527711.7507993.038881e-08
0.9562641.7507183.050021e-08
0.9597691.7506373.061202e-08
0.9632871.7505563.072423e-08
0.9668181.7504763.083686e-08
0.9703621.7503963.094990e-08
0.9739191.7503163.106335e-08
0.9774891.7502363.117722e-08
0.9810721.7501573.129151e-08
0.9846681.7500783.140621e-08
0.9882781.7499993.152134e-08
0.9919011.749923.163689e-08
0.9955361.7498423.175286e-08
0.9991861.7497633.186926e-08
1.002851.7496853.198608e-08
1.006521.7496073.210333e-08
1.010211.7495293.222102e-08
1.013921.7494523.233913e-08
1.017631.7493753.245768e-08
1.021361.7492973.257666e-08
1.025111.749223.269607e-08
1.028871.7491433.281593e-08
1.032641.7490673.293622e-08
1.036421.748993.305696e-08
1.040221.7489143.317813e-08
1.044031.7488383.329976e-08
1.047861.7487613.342182e-08
1.05171.7486863.354434e-08
1.055561.748613.366730e-08
1.059431.7485343.379072e-08
1.061.7485233.380900e-08
1.063311.7484583.391457e-08
1.067211.7483833.403888e-08
1.071121.7483083.416365e-08
1.075051.7482333.428887e-08
1.078991.7481573.441455e-08
1.082941.7480823.454070e-08
1.086911.7480083.466730e-08
1.09091.7479333.479437e-08
1.094891.7478583.492190e-08
1.098911.7477843.504991e-08
1.102941.7477093.517838e-08
1.106981.7476353.530732e-08
1.111041.747563.543673e-08
1.115111.7474863.556662e-08
1.11921.7474123.569699e-08
1.12331.7473383.582783e-08
1.127421.7472643.595916e-08
1.131551.747193.609096e-08
1.13571.7471163.622325e-08
1.139861.7470423.635602e-08
1.144041.7469683.648928e-08
1.148231.7468943.662303e-08
1.152441.746823.675726e-08
1.156671.7467463.689199e-08
1.160911.7466733.702722e-08
1.165161.7465993.716294e-08
1.169431.7465253.729915e-08
1.173721.7464523.743587e-08
1.178021.7463783.757309e-08
1.182341.7463043.771081e-08
1.186671.7462313.784903e-08
1.191021.7461573.798776e-08
1.195391.7460833.812700e-08
1.199771.746013.826675e-08
1.204171.7459363.840702e-08
1.208581.7458623.854779e-08
1.213011.7457893.868909e-08
1.217461.7457153.883090e-08
1.221921.7456413.897323e-08
1.22641.7455673.911608e-08
1.23091.7454933.925946e-08
1.235411.7454193.940336e-08
1.239941.7453453.954779e-08
1.244481.7452713.969275e-08
1.249041.7451973.983824e-08
1.253621.7451233.998426e-08
1.258221.7450494.013082e-08
1.262831.7449754.027792e-08
1.267461.7449014.042555e-08
1.272111.7448264.057373e-08
1.276771.7447524.072245e-08
1.281451.7446774.087171e-08
1.286151.7446034.102153e-08
1.290861.7445284.117189e-08
1.295591.7444534.132280e-08
1.300341.7443784.147426e-08
1.305111.7443034.162628e-08
1.309891.7442284.177886e-08
1.314691.7441534.193200e-08
1.319511.7440774.208570e-08
1.324351.7440024.223996e-08
1.32921.7439264.239479e-08
1.334081.743854.255018e-08
1.338971.7437754.270615e-08
1.343881.7436994.286268e-08
1.34881.7436224.301979e-08
1.353751.7435464.317748e-08
1.358711.743474.333574e-08
1.363691.7433934.349458e-08
1.368691.7433164.365401e-08
1.37371.7432394.381402e-08
1.378741.7431624.397462e-08
1.383791.7430854.413580e-08
1.388871.7430074.429758e-08
1.393961.742934.445995e-08
1.399071.7428524.462292e-08
1.40421.7427744.478648e-08
1.409341.7426964.495064e-08
1.414511.7426174.511540e-08
1.419691.7425394.528077e-08
1.42491.742464.544674e-08
1.430121.7423814.561333e-08
1.435361.7423024.578052e-08
1.440621.7422224.594833e-08
1.445911.7421434.611675e-08
1.451211.7420634.628578e-08
1.456521.7419834.645544e-08
1.461861.7419024.662572e-08
1.467221.7418224.679663e-08
1.47261.7417414.696816e-08
1.4781.741664.714031e-08
1.483421.7415794.731310e-08
1.488851.7414974.748653e-08
1.494311.7414154.766059e-08
1.499791.7413334.783528e-08
1.51.741334.784200e-08
1.505291.7412515.280951e-08
1.51081.7411685.799379e-08
1.516341.7410856.319708e-08
1.52191.7410026.841944e-08
1.527481.7409187.366094e-08
1.533081.7408347.892166e-08
1.53871.740758.420166e-08
1.544341.7406668.950102e-08
1.551.7405819.481980e-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
—