Optical constants

Refractive index of N-LASF9 (SCHOTT)

N-LASF9: n,k 0.365–2.5 µm

Data
formula 2 + tabulated k
Range
0.365–2.5 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength. Note: k data cover 370-2500 nm only; k = 0 elsewhere in the n range 365-2500 nm.

At one wavelength

Range 0.365–2.5 µm
Refractive index n
1.85024
Extinction coefficient k
4.12249e-08
Permittivity ε1
3.4234
Permittivity ε2
1.52552e-07
Absorption coefficient α
0.00881632 cm⁻¹
Penetration depth δ = λ/(2πk)
2.26852e+09 nm
Abbe number Vd
32.17
Chromatic dispersion dn/dλ
-0.133419 µm⁻¹
Group index ng
1.92864
Group velocity dispersion
265.675 fs²/mm
Dispersion parameter D
-1449.4 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-LASF9 (SCHOTT): N-LASF9
schott_n_lasf9 = ls.fetch_refractiveindex("specs", "SCHOTT-optical", "N-LASF9", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(schott_n_lasf9.range_nm)  # (365, 2500) nm
eps = schott_n_lasf9.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=2.00029547λ2λ2−0.0121426017+0.298926886λ2λ2−0.0538736236+1.80691843λ2λ2−156.530829

Valid from 0.365 to 2.5 µm.

Coefficients as stored
CiValue
C10.0
C22.00029547
C30.0121426017
C40.298926886
C50.0538736236
C61.80691843
C7156.530829

Comments and conditions

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 1.05e-06 1.02e-08 -2.38e-11 9.19e-07 1.18e-09 0.257
nd
1.85025
Vd
32.17
glass code
850322.441
glass status
standard
density
value: 4410
thermal expansion
value: 7.37e-06, temperature range: 243 343; value: 8.38e-06, temperature range: 293 573
dPgF
0.0037
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 = 2.47e-06 K⁻¹ at 633 nm, dn/dT = 1.02e-06 K⁻¹ at 1310 nm, dn/dT = 9.11e-07 K⁻¹ at 1550 nm
Notes on the source data (kept exactly as published):
  • k data cover 370-2500 nm only; k = 0 elsewhere in the n range 365-2500 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 418 wavelengths, the same grid as the API and the library
N-LASF9 (SCHOTT), N-LASF9: n and k versus wavelength
λ (µm)nk
0.3651.9238580
0.3667641.9224590
0.3685371.9210840
0.371.9199733.791000e-06
0.3703191.9197333.732178e-06
0.3721091.9184043.402020e-06
0.3739081.9170983.070267e-06
0.3757151.9158142.736910e-06
0.3775321.9145512.401942e-06
0.3793571.9133092.065354e-06
0.381.9128771.946700e-06
0.381191.9120861.850366e-06
0.3830331.9108841.701255e-06
0.3848851.9097011.551422e-06
0.3867451.9085371.400866e-06
0.3886151.9073911.249581e-06
0.391.9065571.137500e-06
0.3904941.9062631.116684e-06
0.3923811.9051531.037064e-06
0.3942781.904069.570590e-07
0.3961841.9029838.766672e-07
0.3980991.9019237.958867e-07
0.41.9008927.157100e-07
0.4000241.900887.151439e-07
0.4019571.8998526.687070e-07
0.40391.8988396.220456e-07
0.4051.8982755.956400e-07
0.4058531.8978415.816400e-07
0.4078151.8968585.494357e-07
0.4097861.895895.170757e-07
0.4117671.8949364.845593e-07
0.4137581.8939954.518857e-07
0.4157581.8930694.190541e-07
0.4177681.8921553.860639e-07
0.4197871.8912553.529141e-07
0.421.8911613.494200e-07
0.4218161.8903673.372216e-07
0.4238561.8894923.235279e-07
0.4259041.8886293.097679e-07
0.4279631.8877782.959414e-07
0.4300321.8869392.820481e-07
0.4321111.8861122.680876e-07
0.43421.8852962.540596e-07
0.4361.8846052.419700e-07
0.4362991.8844912.409190e-07
0.4384081.8836972.334984e-07
0.4405271.8829142.260420e-07
0.4426571.8821422.185496e-07
0.4447971.881382.110210e-07
0.4469471.8806282.034559e-07
0.4491071.8798861.958543e-07
0.4512781.8791531.882159e-07
0.453461.8784311.805406e-07
0.4556521.8777181.728282e-07
0.4578551.8770141.650786e-07
0.461.876341.575300e-07
0.4600681.8763191.574156e-07
0.4622921.8756341.536629e-07
0.4645271.8749571.498920e-07
0.4667721.8742891.461029e-07
0.4690291.8736291.422955e-07
0.4712961.8729781.384697e-07
0.4735741.8723351.346254e-07
0.4758631.87171.307625e-07
0.4781641.8710731.268809e-07
0.4804751.8704541.229806e-07
0.4827981.8698431.190614e-07
0.4851321.8692391.151232e-07
0.4874771.8686431.111661e-07
0.4898331.8680541.071898e-07
0.4922011.8674731.031943e-07
0.4945811.8668989.917942e-08
0.4969721.8663319.514518e-08
0.4993741.865779.109143e-08
0.51.8656269.003500e-08
0.5017881.8652168.845392e-08
0.5042141.8646698.630889e-08
0.5066511.8641288.415348e-08
0.50911.8635948.198765e-08
0.5115611.8630677.981135e-08
0.5140341.8625457.762453e-08
0.5165191.862037.542714e-08
0.5190161.861527.321913e-08
0.5215251.8610177.100044e-08
0.5240461.860526.877103e-08
0.5265791.8600286.653085e-08
0.5291251.8595436.427983e-08
0.5316831.8590626.201793e-08
0.5342531.8585885.974510e-08
0.5368351.8581195.746128e-08
0.5394311.8576555.516642e-08
0.5420381.8571965.286046e-08
0.5446581.8567435.054336e-08
0.5461.8565144.935700e-08
0.5472911.8562954.904225e-08
0.5499371.8558524.839742e-08
0.5525951.8554144.774946e-08
0.5552671.8549814.709837e-08
0.5579511.8545534.644414e-08
0.5606481.8541294.578674e-08
0.5633581.8537114.512617e-08
0.5660821.8532974.446240e-08
0.5688181.8528874.379542e-08
0.5715681.8524824.312522e-08
0.5743311.8520824.245178e-08
0.5771071.8516864.177508e-08
0.5798971.8512944.109512e-08
0.581.851284.107000e-08
0.58271.8509074.112502e-08
0.5855171.8505244.118241e-08
0.5883471.8501454.124008e-08
0.5911921.849774.129803e-08
0.5940491.8493994.135626e-08
0.5969211.8490324.141477e-08
0.5998071.8486694.147356e-08
0.6027061.848314.153264e-08
0.605621.8479554.159200e-08
0.6085471.8476034.165165e-08
0.6114891.8472554.171159e-08
0.6144451.8469114.177182e-08
0.6174151.8465714.183234e-08
0.621.8462794.188500e-08
0.62041.8462344.186915e-08
0.6233991.84594.175031e-08
0.6264131.845574.163090e-08
0.6294411.8452444.151091e-08
0.6324831.8449214.139034e-08
0.6355411.8446014.126919e-08
0.6386131.8442844.114745e-08
0.64171.8439714.102513e-08
0.6448021.8436614.090221e-08
0.6479191.8433544.077870e-08
0.6510511.843054.065459e-08
0.6541991.842754.052988e-08
0.6573611.8424524.040457e-08
0.661.8422074.030000e-08
0.6605391.8421574.018030e-08
0.6637321.8418653.947104e-08
0.666941.8415773.875834e-08
0.6701651.8412913.804220e-08
0.6734041.8410083.732260e-08
0.6766591.8407273.659952e-08
0.679931.840453.587295e-08
0.6832171.8401753.514286e-08
0.686521.8399033.440924e-08
0.6898391.8396333.367208e-08
0.6931731.8393663.293135e-08
0.6965241.8391023.218704e-08
0.6998911.838843.143914e-08
0.71.8388323.141500e-08
0.7032751.8385813.131394e-08
0.7066741.8383243.120902e-08
0.710091.838073.110360e-08
0.7135231.8378183.099766e-08
0.7169721.8375683.089122e-08
0.7204381.8373213.078425e-08
0.7239211.8370763.067678e-08
0.727421.8368343.056878e-08
0.7309371.8365943.046026e-08
0.734471.8363553.035121e-08
0.7380211.836123.024164e-08
0.7415881.8358863.013154e-08
0.7451731.8356543.002091e-08
0.7487751.8354252.990974e-08
0.7523951.8351972.979803e-08
0.7560321.8349722.968578e-08
0.7596871.8347492.957300e-08
0.7633591.8345282.945966e-08
0.7670491.8343082.934578e-08
0.7707571.8340912.923135e-08
0.7744831.8338752.911636e-08
0.7782271.8336622.900082e-08
0.7819891.833452.888472e-08
0.7857691.833242.876806e-08
0.7895681.8330322.865084e-08
0.7933851.8328262.853304e-08
0.797221.8326222.841468e-08
0.8010741.8324192.829575e-08
0.8049461.8322182.817624e-08
0.8088371.8320192.805616e-08
0.8127471.8318212.793549e-08
0.8166761.8316252.781424e-08
0.8206241.8314312.769240e-08
0.8245911.8312382.756998e-08
0.8285771.8310472.744696e-08
0.8325831.8308572.732335e-08
0.8366071.8306692.719914e-08
0.8406521.8304832.707433e-08
0.8447151.8302982.694892e-08
0.8487991.8301142.682290e-08
0.8529021.8299322.669627e-08
0.8570251.8297512.656903e-08
0.8611681.8295722.644118e-08
0.8653311.8293942.631271e-08
0.8695141.8292182.618361e-08
0.8737171.8290432.605389e-08
0.8779411.8288692.592355e-08
0.8821851.8286962.579257e-08
0.8864491.8285252.566096e-08
0.8907351.8283552.552872e-08
0.895041.8281862.539584e-08
0.8993671.8280192.526231e-08
0.9037151.8278532.512814e-08
0.9080831.8276882.499332e-08
0.9124731.8275242.485784e-08
0.9168841.8273612.472172e-08
0.9213161.82722.458493e-08
0.925771.8270392.444748e-08
0.9302451.826882.430937e-08
0.9347421.8267222.417060e-08
0.9392611.8265652.403115e-08
0.9438011.8264092.389102e-08
0.9483641.8262542.375022e-08
0.9529481.82612.360874e-08
0.9575551.8259472.346657e-08
0.9621841.8257952.332372e-08
0.9668351.8256442.318018e-08
0.9715091.8254932.303594e-08
0.9762051.8253442.289101e-08
0.9809241.8251962.274537e-08
0.9856661.8250492.259903e-08
0.9904311.8249022.245199e-08
0.9952191.8247572.230423e-08
1.000031.8246122.215576e-08
1.004861.8244682.200657e-08
1.009721.8243262.185666e-08
1.01461.8241832.170602e-08
1.019511.8240422.155466e-08
1.024441.8239012.140256e-08
1.029391.8237622.124973e-08
1.034361.8236232.109616e-08
1.039361.8234842.094185e-08
1.044391.8233472.078680e-08
1.049441.823212.063099e-08
1.054511.8230742.047443e-08
1.059611.8229382.031711e-08
1.061.8229282.030500e-08
1.064731.8228032.079165e-08
1.069881.8226692.132123e-08
1.075051.8225362.185337e-08
1.080251.8224032.238809e-08
1.085471.8222712.292539e-08
1.090711.8221392.346528e-08
1.095991.8220082.400779e-08
1.101291.8218772.455291e-08
1.106611.8217472.510068e-08
1.111961.8216182.565109e-08
1.117331.8214892.620416e-08
1.122741.8213612.675990e-08
1.128161.8212332.731834e-08
1.133621.8211062.787947e-08
1.13911.8209792.844331e-08
1.14461.8208522.900988e-08
1.150141.8207272.957919e-08
1.15571.8206013.015125e-08
1.161281.8204763.072607e-08
1.16691.8203513.130368e-08
1.172541.8202273.188408e-08
1.17821.8201033.246728e-08
1.18391.819983.305330e-08
1.189621.8198573.364215e-08
1.195371.8197343.423386e-08
1.201151.8196113.482842e-08
1.206961.8194893.542585e-08
1.212791.8193673.602618e-08
1.218661.8192463.662940e-08
1.224551.8191253.723554e-08
1.230471.8190043.784461e-08
1.236421.8188833.845663e-08
1.242391.8187633.907160e-08
1.24841.8186433.968955e-08
1.254431.8185234.031049e-08
1.26051.8184034.093442e-08
1.266591.8182844.156138e-08
1.272711.8181644.219136e-08
1.278871.8180454.282439e-08
1.285051.8179264.346048e-08
1.291261.8178074.409964e-08
1.29751.8176894.474189e-08
1.303771.817574.538725e-08
1.310081.8174524.603573e-08
1.316411.8173334.668734e-08
1.322771.8172154.734210e-08
1.329171.8170974.800003e-08
1.335591.8169794.866114e-08
1.342051.8168614.932544e-08
1.348541.8167434.999296e-08
1.355061.8166255.066370e-08
1.361611.8165075.133768e-08
1.368191.8163895.201493e-08
1.37481.8162715.269544e-08
1.381451.8161535.337925e-08
1.388131.8160365.406636e-08
1.394841.8159185.475679e-08
1.401581.81585.545056e-08
1.408351.8156825.614769e-08
1.415161.8155635.684818e-08
1.4221.8154455.755206e-08
1.428881.8153275.825935e-08
1.435781.8152085.897005e-08
1.442731.815095.968419e-08
1.44971.8149716.040178e-08
1.456711.8148526.112284e-08
1.463751.8147336.184738e-08
1.470831.8146146.257543e-08
1.477941.8144956.330700e-08
1.485081.8143766.404210e-08
1.492261.8142566.478076e-08
1.499471.8141366.552298e-08
1.506721.8140166.626880e-08
1.5141.8138956.701822e-08
1.521321.8137756.777126e-08
1.528681.8136546.852795e-08
1.531.8136326.866400e-08
1.536071.8135337.502123e-08
1.543491.8134118.280136e-08
1.550951.8132899.061910e-08
1.558451.8131679.847464e-08
1.565991.8130451.063681e-07
1.573561.8129221.142998e-07
1.581161.8127991.222698e-07
1.588811.8126761.302783e-07
1.596491.8125521.383256e-07
1.60421.8124271.464117e-07
1.611961.8123031.545370e-07
1.619751.8121781.627015e-07
1.627581.8120521.709055e-07
1.635451.8119261.791491e-07
1.643351.81181.874326e-07
1.65131.8116731.957562e-07
1.659281.8115462.041199e-07
1.66731.8114182.125241e-07
1.675361.811292.209690e-07
1.683461.8111612.294546e-07
1.69161.8110322.379813e-07
1.699781.8109022.465492e-07
1.707991.8107712.551585e-07
1.716251.810642.638094e-07
1.724551.8105092.725022e-07
1.732881.8103762.812369e-07
1.741261.8102442.900139e-07
1.749681.810112.988334e-07
1.758131.8099763.076954e-07
1.766631.8098413.166003e-07
1.775171.8097063.255482e-07
1.783761.809573.345394e-07
1.792381.8094333.435741e-07
1.801041.8092953.526524e-07
1.809751.8091573.617747e-07
1.81851.8090183.709410e-07
1.827291.8088793.801516e-07
1.836121.8087383.894068e-07
1.8451.8085973.987067e-07
1.853921.8084554.080515e-07
1.862881.8083124.174415e-07
1.871881.8081684.268770e-07
1.880931.8080244.363580e-07
1.890021.8078784.458848e-07
1.899161.8077324.554578e-07
1.908341.8075854.650769e-07
1.917571.8074374.747426e-07
1.926841.8072884.844550e-07
1.936151.8071384.942144e-07
1.945511.8069875.040210e-07
1.954921.8068355.138749e-07
1.964371.8066825.237765e-07
1.971.8065915.296800e-07
1.973861.8065285.512633e-07
1.98341.8063736.045957e-07
1.992991.8062176.581860e-07
2.002631.806067.120353e-07
2.012311.8059027.661449e-07
2.022031.8057438.205161e-07
2.031811.8055838.751501e-07
2.041631.8054229.300483e-07
2.05151.8052599.852118e-07
2.061421.8050961.040642e-06
2.071381.8049311.096340e-06
2.08141.8047651.152307e-06
2.091461.8045981.208545e-06
2.101571.8044291.265055e-06
2.111731.804261.321838e-06
2.121931.8040891.378896e-06
2.132191.8039161.436229e-06
2.14251.8037431.493839e-06
2.152861.8035681.551728e-06
2.163261.8033921.609897e-06
2.173721.8032141.668347e-06
2.184231.8030351.727079e-06
2.194791.8028551.786096e-06
2.20541.8026731.845398e-06
2.216061.802491.904986e-06
2.226771.8023051.964862e-06
2.237541.8021192.025028e-06
2.248351.8019322.085485e-06
2.259221.8017432.146234e-06
2.270141.8015522.207277e-06
2.281121.801362.268614e-06
2.292141.8011662.330249e-06
2.303221.800972.392181e-06
2.314361.8007732.454412e-06
2.3251.8005842.513900e-06
2.325541.8005742.518811e-06
2.336791.8003742.620161e-06
2.348081.8001722.722001e-06
2.359431.7999682.824334e-06
2.370841.7997622.927161e-06
2.38231.7995553.030485e-06
2.393821.7993463.134309e-06
2.405391.7991353.238634e-06
2.417021.7989223.343464e-06
2.42871.7987073.448801e-06
2.440441.798493.554646e-06
2.452241.7982723.661004e-06
2.464091.7980513.767875e-06
2.4761.7978293.875264e-06
2.487971.7976043.983171e-06
2.51.7973784.091600e-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
—