Optical constants

Refractive index of N-LASF31 (SCHOTT)

N-LASF31: n,k 0.32–2.5 µm

Data
formula 2 + tabulated k
Range
0.32–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.32–2.5 µm
Refractive index n
1.88066
Extinction coefficient k
1.31389e-08
Permittivity ε1
3.5369
Permittivity ε2
4.94196e-08
Absorption coefficient α
0.00280987 cm⁻¹
Penetration depth δ = λ/(2πk)
7.11777e+09 nm
Abbe number Vd
41.01
Chromatic dispersion dn/dλ
-0.10967 µm⁻¹
Group index ng
1.94511
Group velocity dispersion
207.086 fs²/mm
Dispersion parameter D
-1129.76 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-LASF31 (SCHOTT): N-LASF31
schott_n_lasf31 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-LASF31", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_lasf31.range_nm)  # (320, 2500) nm
eps = schott_n_lasf31.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=1.71317198λ2λ2−0.00819172228+0.718575109λ2λ2−0.0297801704+1.7233247λ2λ2−138.461313

Valid from 0.32 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C21.71317198
C30.00819172228
C40.718575109
C50.0297801704
C61.7233247
C7138.461313

Comments and conditions

was replaced by N-LASF31A

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 2.29e-06 8.93e-09 -1.59e-11 6.52e-07 8.09e-10 0.236
nd
1.88067E+00
Vd
4.10100E+01
glass code
881410.541
glass status
preferred
density
value: 5410
thermal expansion
value: 6.8e-06, temperature range: 243 343; value: 7.7e-06, temperature range: 293 573
dPgF
-0.0084
resistance
acid: 2.0; stain: 0.0; alkali: 1.0; climatic: 1.0; phosphate: 1.0

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = 2.81e-06 K⁻¹ at 633 nm, dn/dT = 1.76e-06 K⁻¹ at 1310 nm, dn/dT = 1.68e-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 421 wavelengths, the same grid as the API and the library
N-LASF31 (SCHOTT), N-LASF31: n and k versus wavelength
λ (µm)nk
0.321.9682773.984800e-06
0.3216531.9667743.918375e-06
0.3233141.9652953.851606e-06
0.3249851.9638393.784493e-06
0.3266631.9624063.717033e-06
0.3283511.9609963.649225e-06
0.3300471.9596073.581066e-06
0.3317521.958243.512556e-06
0.3334651.9568943.443691e-06
0.3341.9564793.422200e-06
0.3351881.9555683.297230e-06
0.3369191.9542623.115053e-06
0.3386591.9529762.931935e-06
0.3404091.951712.747872e-06
0.3421671.9504622.562857e-06
0.3439351.9492332.376887e-06
0.3457111.9480222.189957e-06
0.3474971.9468292.002061e-06
0.3492921.9456531.813194e-06
0.351.9451961.738700e-06
0.3510961.9444951.677564e-06
0.352911.9433541.576427e-06
0.3547331.9422291.474767e-06
0.3565651.941121.372582e-06
0.3584071.9400271.269869e-06
0.3602581.938951.166626e-06
0.3621191.9378881.062849e-06
0.363991.9368419.585360e-07
0.3651.9362849.022000e-07
0.365871.9358098.753230e-07
0.367761.9347918.169365e-07
0.369661.9337887.582484e-07
0.371.933617.477300e-07
0.3715691.9327987.121669e-07
0.3734881.9318236.686633e-07
0.3754181.930866.249349e-07
0.3773571.9299125.809807e-07
0.3793061.9289765.367994e-07
0.381.9286475.210700e-07
0.3812651.9280535.003260e-07
0.3832351.9271424.680393e-07
0.3852141.9262444.355859e-07
0.3872041.9253584.029648e-07
0.3892041.9244843.701751e-07
0.391.924143.571300e-07
0.3912151.9236213.444424e-07
0.3932361.9227713.233350e-07
0.3952671.9219313.021186e-07
0.3973091.9211032.807925e-07
0.3993611.9202852.593563e-07
0.41.9200342.526800e-07
0.4014241.9194792.447329e-07
0.4034971.9186832.331583e-07
0.4051.9181152.247700e-07
0.4055821.9178972.226816e-07
0.4076771.9171222.151576e-07
0.4097821.9163572.075948e-07
0.4118991.9156011.999930e-07
0.4140271.9148561.923518e-07
0.4161651.914121.846712e-07
0.4183151.9133941.769510e-07
0.421.9128331.709000e-07
0.4204761.9126761.697099e-07
0.4226481.9119681.642786e-07
0.4248311.9112691.588193e-07
0.4270261.9105791.533318e-07
0.4292311.9098981.478159e-07
0.4314491.9092251.422716e-07
0.4336771.9085611.366986e-07
0.4359171.9079051.310968e-07
0.4361.9078811.308900e-07
0.4381691.9072571.272487e-07
0.4404321.9066171.234491e-07
0.4427071.9059861.196299e-07
0.4449941.9053621.157909e-07
0.4472931.9047461.119321e-07
0.4496031.9041371.080534e-07
0.4519261.9035361.041546e-07
0.454261.9029421.002357e-07
0.4566071.9023569.629657e-08
0.4589651.9017769.233708e-08
0.461.9015259.060000e-08
0.4613361.9012048.902892e-08
0.4637191.9006388.622667e-08
0.4661141.900088.340993e-08
0.4685221.8995288.057865e-08
0.4709421.8989837.773274e-08
0.4733751.8984447.487213e-08
0.475821.8979127.199674e-08
0.4782781.8973866.910650e-08
0.4807481.8968676.620133e-08
0.4832321.8963536.328116e-08
0.4857281.8958466.034590e-08
0.4882371.8953445.739547e-08
0.4907591.8948495.442981e-08
0.4932941.8943595.144883e-08
0.4958421.8938754.845245e-08
0.4984031.8933974.544060e-08
0.51.8931034.356300e-08
0.5009781.8929244.300829e-08
0.5035661.8924574.154022e-08
0.5061671.8919964.006457e-08
0.5087811.8915393.858130e-08
0.5114091.8910883.709036e-08
0.5140511.8906423.559173e-08
0.5167061.8902013.408535e-08
0.5193761.8897653.257119e-08
0.5220581.8893343.104921e-08
0.5247551.8889082.951937e-08
0.5274661.8884872.798163e-08
0.530191.8880712.643594e-08
0.5329291.8876592.488227e-08
0.5356821.8872522.332057e-08
0.5384491.886852.175080e-08
0.541231.8864522.017293e-08
0.5440261.8860581.858691e-08
0.5461.8857841.746700e-08
0.5468361.8856691.735639e-08
0.5496611.8852841.698270e-08
0.55251.8849041.660709e-08
0.5553541.8845271.622953e-08
0.5582231.8841551.585002e-08
0.5611061.8837871.546855e-08
0.5640041.8834231.508511e-08
0.5669181.8830631.469969e-08
0.5698461.8827071.431228e-08
0.572791.8823551.392287e-08
0.5757491.8820061.353144e-08
0.5787231.8816621.313800e-08
0.581.8815151.296900e-08
0.5817121.8813211.300726e-08
0.5847171.8809831.307442e-08
0.5877371.880651.314192e-08
0.5907731.880321.320978e-08
0.5938251.8799931.327798e-08
0.5968921.879671.334654e-08
0.5999751.879351.341545e-08
0.6030741.8790341.348472e-08
0.606191.8787211.355434e-08
0.6093211.8784121.362432e-08
0.6124681.8781051.369467e-08
0.6156321.8778021.376538e-08
0.6188121.8775021.383645e-08
0.621.8773911.386300e-08
0.6220091.8772051.380174e-08
0.6252221.8769111.370374e-08
0.6284511.876621.360524e-08
0.6316971.8763331.350623e-08
0.634961.8760481.340671e-08
0.638241.8757661.330667e-08
0.6415371.8754871.320612e-08
0.6448511.875211.310505e-08
0.6481821.8749371.300345e-08
0.651531.8746661.290133e-08
0.6548961.8743981.279868e-08
0.6582781.8741331.269551e-08
0.661.8739991.264300e-08
0.6616791.873871.267515e-08
0.6650971.873611.274060e-08
0.6685321.8733531.280639e-08
0.6719861.8730981.287252e-08
0.6754571.8728461.293899e-08
0.6789461.8725961.300581e-08
0.6824531.8723481.307297e-08
0.6859781.8721031.314048e-08
0.6895211.871861.320834e-08
0.6930831.871621.327654e-08
0.6966631.8713821.334510e-08
0.71.8711631.340900e-08
0.7002621.8711461.341649e-08
0.7038791.8709131.351991e-08
0.7075151.8706811.362386e-08
0.711171.8704521.372836e-08
0.7148431.8702251.383339e-08
0.7185361.8700011.393896e-08
0.7222471.8697781.404509e-08
0.7259781.8695571.415175e-08
0.7297281.8693391.425897e-08
0.7334971.8691221.436675e-08
0.7372861.8689071.447508e-08
0.7410951.8686951.458397e-08
0.7449231.8684841.469342e-08
0.7487711.8682751.480344e-08
0.7526391.8680681.491402e-08
0.7565261.8678631.502518e-08
0.7604341.867661.513691e-08
0.7643621.8674581.524922e-08
0.768311.8672591.536211e-08
0.7722791.8670611.547558e-08
0.7762681.8668641.558964e-08
0.7802781.866671.570428e-08
0.7843091.8664771.581952e-08
0.788361.8662861.593536e-08
0.7924321.8660961.605179e-08
0.7965261.8659081.616883e-08
0.800641.8657221.628646e-08
0.8047761.8655371.640471e-08
0.8089331.8653531.652357e-08
0.8131111.8651721.664304e-08
0.8173111.8649911.676313e-08
0.8215331.8648121.688384e-08
0.8257771.8646351.700517e-08
0.8300421.8644591.712713e-08
0.834331.8642841.724972e-08
0.838641.8641111.737294e-08
0.8429721.8639391.749680e-08
0.8473261.8637681.762130e-08
0.8517031.8635991.774644e-08
0.8561021.8634311.787222e-08
0.8605241.8632641.799866e-08
0.864971.8630991.812575e-08
0.8694371.8629351.825350e-08
0.8739291.8627721.838191e-08
0.8784431.862611.851098e-08
0.882981.8624491.864072e-08
0.8875411.862291.877112e-08
0.8921261.8621311.890220e-08
0.8967341.8619741.903396e-08
0.9013661.8618181.916640e-08
0.9060221.8616631.929952e-08
0.9107021.8615091.943333e-08
0.9154071.8613561.956783e-08
0.9201351.8612041.970303e-08
0.9248881.8610531.983893e-08
0.9296661.8609031.997552e-08
0.9344681.8607542.011282e-08
0.9392951.8606062.025084e-08
0.9441471.8604582.038956e-08
0.9490241.8603122.052900e-08
0.9539261.8601672.066916e-08
0.9588531.8600222.081005e-08
0.9638061.8598792.095166e-08
0.9687851.8597362.109401e-08
0.9737891.8595942.123708e-08
0.9788191.8594532.138090e-08
0.9838751.8593132.152547e-08
0.9889571.8591732.167077e-08
0.9940661.8590342.181683e-08
0.9992011.8588962.196365e-08
1.004361.8587592.211122e-08
1.009551.8586222.225955e-08
1.014761.8584872.240865e-08
1.020011.8583512.255852e-08
1.025281.8582172.270917e-08
1.030571.8580832.286059e-08
1.035891.857952.301280e-08
1.041251.8578172.316579e-08
1.046621.8576852.331957e-08
1.052031.8575542.347414e-08
1.057461.8574232.362952e-08
1.061.8573622.370200e-08
1.062931.8572922.379801e-08
1.068421.8571632.397810e-08
1.073941.8570332.415912e-08
1.079481.8569052.434108e-08
1.085061.8567762.452397e-08
1.090671.8566492.470781e-08
1.09631.8565212.489260e-08
1.101961.8563952.507835e-08
1.107651.8562682.526505e-08
1.113381.8561422.545272e-08
1.119131.8560172.564135e-08
1.124911.8558912.583097e-08
1.130721.8557672.602156e-08
1.136561.8556422.621313e-08
1.142431.8555182.640570e-08
1.148331.8553952.659926e-08
1.154261.8552712.679382e-08
1.160231.8551482.698938e-08
1.166221.8550252.718596e-08
1.172241.8549032.738355e-08
1.17831.8547812.758216e-08
1.184381.8546592.778179e-08
1.19051.8545372.798246e-08
1.196651.8544152.818416e-08
1.202831.8542942.838691e-08
1.209051.8541732.859070e-08
1.215291.8540522.879555e-08
1.221571.8539312.900146e-08
1.227881.8538112.920842e-08
1.234221.853692.941646e-08
1.24061.853572.962557e-08
1.2471.853452.983576e-08
1.253451.853333.004704e-08
1.259921.853213.025941e-08
1.266431.853093.047288e-08
1.272971.852973.068744e-08
1.279551.852853.090312e-08
1.286161.852733.111991e-08
1.29281.852613.133782e-08
1.299481.8524913.155686e-08
1.306191.8523713.177703e-08
1.312941.8522513.199833e-08
1.319721.8521313.222078e-08
1.326541.8520113.244438e-08
1.333391.8518913.266913e-08
1.340281.8517713.289504e-08
1.34721.8516513.312212e-08
1.354161.8515313.335038e-08
1.361151.8514113.357981e-08
1.368181.851293.381043e-08
1.375251.851173.404224e-08
1.382351.8510493.427524e-08
1.38951.8509283.450945e-08
1.396671.8508073.474487e-08
1.403891.8506863.498151e-08
1.411141.8505643.521937e-08
1.418431.8504423.545845e-08
1.425761.850323.569877e-08
1.433121.8501983.594034e-08
1.440521.8500753.618315e-08
1.447961.8499533.642721e-08
1.455441.8498293.667254e-08
1.462961.8497063.691913e-08
1.470521.8495823.716700e-08
1.478111.8494583.741614e-08
1.485751.8493343.766658e-08
1.493421.8492093.791831e-08
1.501141.8490843.817133e-08
1.508891.8489583.842567e-08
1.516691.8488323.868132e-08
1.524521.8487063.893829e-08
1.531.8486173.911800e-08
1.53241.8485794.029882e-08
1.540311.8484514.420015e-08
1.548271.8483244.812164e-08
1.556271.8481955.206338e-08
1.56431.8480665.602548e-08
1.572381.8479376.000805e-08
1.580511.8478076.401119e-08
1.588671.8476776.803501e-08
1.596881.8475467.207962e-08
1.605131.8474147.614512e-08
1.613421.8472828.023161e-08
1.621751.8471498.433922e-08
1.630131.8470168.846804e-08
1.638551.8468829.261819e-08
1.647011.8467479.678978e-08
1.655521.8466121.009829e-07
1.664071.8464761.051977e-07
1.672671.8463391.094343e-07
1.681311.8462021.136927e-07
1.689991.8460631.179732e-07
1.698721.8459241.222757e-07
1.70751.8457851.266005e-07
1.716321.8456441.309477e-07
1.725181.8455031.353172e-07
1.734091.8453611.397094e-07
1.743051.8452181.441242e-07
1.752061.8450741.485619e-07
1.761111.8449291.530224e-07
1.77021.8447841.575060e-07
1.779351.8446371.620128e-07
1.788541.844491.665429e-07
1.797781.8443411.710963e-07
1.807061.8441921.756733e-07
1.81641.8440421.802739e-07
1.825781.843891.848982e-07
1.835211.8437381.895465e-07
1.844691.8435851.942188e-07
1.854221.843431.989152e-07
1.86381.8432752.036359e-07
1.873421.8431182.083809e-07
1.88311.8429612.131505e-07
1.892831.8428022.179447e-07
1.902611.8426422.227636e-07
1.912431.8424812.276075e-07
1.922311.8423192.324763e-07
1.932241.8421552.373704e-07
1.942221.841992.422897e-07
1.952261.8418242.472344e-07
1.962341.8416572.522047e-07
1.971.841532.559800e-07
1.972481.8414892.650734e-07
1.982671.8413193.024855e-07
1.992911.8411483.400909e-07
2.00321.8409753.778906e-07
2.013551.8408014.158855e-07
2.023951.8406264.540766e-07
2.03441.8404494.924651e-07
2.044911.8402715.310518e-07
2.055481.8400915.698378e-07
2.066091.839916.088242e-07
2.076771.8397286.480120e-07
2.087491.8395436.874022e-07
2.098281.8393587.269959e-07
2.109111.839177.667941e-07
2.120011.8389818.067979e-07
2.130961.8387918.470083e-07
2.141971.8385998.874264e-07
2.153031.8384059.280533e-07
2.164151.8382099.688901e-07
2.175331.8380121.009938e-06
2.186571.8378131.051197e-06
2.197861.8376121.092670e-06
2.209221.8374091.134357e-06
2.220631.8372051.176260e-06
2.23211.8369991.218379e-06
2.243631.836791.260715e-06
2.255221.836581.303270e-06
2.266871.8363681.346045e-06
2.278581.8361541.389041e-06
2.290351.8359381.432259e-06
2.302181.835721.475700e-06
2.314071.83551.519366e-06
2.3251.8352971.559500e-06
2.326021.8352781.579052e-06
2.338041.8350541.808642e-06
2.350121.8348272.039419e-06
2.362251.8345982.271387e-06
2.374461.8343682.504554e-06
2.386721.8341342.738925e-06
2.399051.8338992.974506e-06
2.411441.8336613.211305e-06
2.42391.8334213.449327e-06
2.436421.8331793.688578e-06
2.449011.8329343.929065e-06
2.461661.8326874.170794e-06
2.474371.8324374.413772e-06
2.487151.8321854.658005e-06
2.51.831934.903500e-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
—