Optical constants

Refractive index of D-K9GT-25 (CDGM)

D-K9GT-25: n,k 0.302–2.325 µm

Data
formula 2 + tabulated k
Range
0.302–2.325 µm
Temperature
293 K
Licence
CC0-1.0

Plot

Click the plot to set the calculator wavelength.

At one wavelength

Range 0.302–2.325 µm
Refractive index n
1.51577
Extinction coefficient k
9.36134e-09
Permittivity ε1
2.29755
Permittivity ε2
2.83793e-08
Absorption coefficient α
0.00200201 cm⁻¹
Penetration depth δ = λ/(2πk)
9.98996e+09 nm
Abbe number Vd
63.99
Chromatic dispersion dn/dλ
-0.0418477 µm⁻¹
Group index ng
1.54036
Group velocity dispersion
70.1623 fs²/mm
Dispersion parameter D
-382.773 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

# D-K9GT-25 (CDGM): D-K9GT-25
cdgm_d_k9gt_25 = ls.fetch_refractiveindex("specs", "CDGM-optical", "D-K9GT-25", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(cdgm_d_k9gt_25.range_nm)  # (302, 2325) nm
eps = cdgm_d_k9gt_25.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=1.08234297λ2λ2−107.907645+0.548438846λ2λ2−0.002190929+0.719999855λ2λ2−0.013407002

Valid from 0.302 to 2.325 µm.

Coefficients as stored
CiValue
C10.0
C21.08234297
C3107.907645
C40.548438846
C50.002190929
C60.719999855
C70.013407002

Comments and conditions

anneal rate:25°C/h

Conditions

temperature
293 K

Properties

thermal dispersion
type: formula A, coefficients: 4.87e-06 1.55e-08 -1.35e-11 4.17e-07 5.2e-10 0.177
nd
1.515770
Vd
63.989637
glass code
516640
density
value: 2410
thermal expansion
value: 6.3e-06, temperature range: 243 343; value: 7.8e-06, temperature range: 293 573
dPgF
-0.0029
resistance
climatic: 1.0

Thermo-optic coefficient

  • Schott thermal-dispersion model (reference temperature 293.0 K): dn/dT = 2.56e-06 K⁻¹ at 633 nm, dn/dT = 2.14e-06 K⁻¹ at 1310 nm, dn/dT = 2.10e-06 K⁻¹ at 1550 nm

References

Cite

CDGM Zemax catalog 2022-06 (obtained from http://www.cdgmgd.com); See also CDGM optical 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 431 wavelengths, the same grid as the API and the library
D-K9GT-25 (CDGM), D-K9GT-25: n and k versus wavelength
λ (µm)nk
0.3021.5508396.512220e-07
0.3035491.5503145.938556e-07
0.3051061.5497965.361949e-07
0.306671.5492844.782386e-07
0.3082431.5487794.199850e-07
0.3098241.5482813.614327e-07
0.311.5482263.549100e-07
0.3114131.5477883.308763e-07
0.313011.5473023.037083e-07
0.3146151.5468232.764009e-07
0.3162291.5463492.489535e-07
0.317851.5458812.213653e-07
0.3194811.5454191.936357e-07
0.321.5452741.848000e-07
0.3211191.5449631.758107e-07
0.3227661.5445131.625814e-07
0.3244211.5440681.492843e-07
0.3260851.5436291.359190e-07
0.3277571.5431951.224852e-07
0.3294381.5427671.089824e-07
0.331.5426251.044700e-07
0.3311281.5423431.004134e-07
0.3328261.5419269.430521e-08
0.3345331.5415138.816565e-08
0.3362491.5411058.199460e-08
0.3379731.5407027.579190e-08
0.3397061.5403046.955740e-08
0.341.5402386.850100e-08
0.3414481.5399116.631769e-08
0.34321.5395236.367822e-08
0.344961.539146.102521e-08
0.3467291.5387615.835860e-08
0.3485071.5383865.567831e-08
0.351.5380775.342800e-08
0.3502941.5380165.304419e-08
0.3520911.5376515.070192e-08
0.3538971.537294.834765e-08
0.3557121.5369334.598130e-08
0.3575361.5365814.360281e-08
0.3593691.5362324.121213e-08
0.361.5361144.039000e-08
0.3612121.5358883.908078e-08
0.3630651.5355483.708046e-08
0.3649271.5352123.506989e-08
0.3667981.534883.304901e-08
0.368681.5345513.101777e-08
0.371.5343242.959200e-08
0.370571.5342272.928953e-08
0.3724711.5339062.828170e-08
0.3743811.5335892.726871e-08
0.3763011.5332762.625053e-08
0.3782311.5329662.522712e-08
0.381.5326872.428900e-08
0.3801711.532662.408669e-08
0.382121.5323582.177628e-08
0.384081.5320591.945402e-08
0.386051.5317631.711986e-08
0.388031.5314711.477372e-08
0.391.5311851.243900e-08
0.390021.5311821.242699e-08
0.392021.5308961.121358e-08
0.394031.5306149.993942e-09
0.3960511.5303358.768049e-09
0.3980821.5300597.535869e-09
0.41.5298026.372600e-09
0.4001241.5297866.374576e-09
0.4021761.5295166.407265e-09
0.4042391.5292496.440121e-09
0.4063121.5289856.473146e-09
0.4083961.5287256.506341e-09
0.410491.5284676.539706e-09
0.4125951.5282126.573242e-09
0.4147111.5279596.606950e-09
0.4168381.527716.640830e-09
0.4189761.5274636.674885e-09
0.421.5273476.691200e-09
0.4211251.5272196.709114e-09
0.4232841.5269786.743519e-09
0.4254551.526746.778100e-09
0.4276371.5265046.812858e-09
0.429831.526276.847795e-09
0.4320351.5260396.882911e-09
0.434251.5258116.918207e-09
0.4364771.5255856.953684e-09
0.4387161.5253616.989343e-09
0.441.5252357.009800e-09
0.4409661.525147.025190e-09
0.4432271.5249227.061227e-09
0.44551.5247057.097449e-09
0.4477851.5244917.133856e-09
0.4500821.524287.170451e-09
0.452391.524077.207233e-09
0.454711.5238637.244203e-09
0.4570421.5236587.281363e-09
0.4593861.5234557.318714e-09
0.461.5234037.328500e-09
0.4617421.5232547.356248e-09
0.464111.5230567.393971e-09
0.466491.5228597.431887e-09
0.4688831.5226657.469998e-09
0.4712871.5224727.508305e-09
0.4737041.5222827.546808e-09
0.4761341.5220937.585508e-09
0.4785751.5219077.624407e-09
0.481.5217997.647100e-09
0.481031.5217227.663505e-09
0.4834971.521547.702804e-09
0.4859761.5213597.742304e-09
0.4884691.521187.782007e-09
0.4909741.5210037.821914e-09
0.4934921.5208277.862025e-09
0.4960231.5206547.902342e-09
0.4985671.5204827.942866e-09
0.51.5203867.965700e-09
0.5011231.5203127.983599e-09
0.5036931.5201438.024545e-09
0.5062771.5199778.065700e-09
0.5088731.5198128.107067e-09
0.5114831.5196488.148646e-09
0.5141061.5194878.190438e-09
0.5167431.5193268.232444e-09
0.5193931.5191688.274666e-09
0.5220561.5190118.317104e-09
0.5247341.5188558.359760e-09
0.5274251.5187018.402635e-09
0.530131.5185498.445729e-09
0.5328491.5183988.489045e-09
0.5355811.5182488.532583e-09
0.5383281.51818.576344e-09
0.5410891.5179538.620329e-09
0.5438641.5178088.664540e-09
0.5466531.5176648.708978e-09
0.5494571.5175218.753644e-09
0.551.5174948.762300e-09
0.5522751.517388.798538e-09
0.5551071.517248.843663e-09
0.5579541.5171028.889020e-09
0.5608151.5169648.934609e-09
0.5636911.5168288.980431e-09
0.5665821.5166939.026489e-09
0.5694881.516569.072783e-09
0.5724091.5164289.119315e-09
0.5753441.5162969.166085e-09
0.5782951.5161669.213095e-09
0.5812611.5160389.260346e-09
0.5842421.515919.307839e-09
0.5872381.5157849.355576e-09
0.590251.5156589.403558e-09
0.5932771.5155349.451786e-09
0.5963191.5154119.500261e-09
0.5993781.5152899.548985e-09
0.61.5152649.558900e-09
0.6024521.5151689.597934e-09
0.6055411.5150489.647128e-09
0.6086471.5149299.696574e-09
0.6117681.5148119.746274e-09
0.6149061.5146949.796228e-09
0.6180591.5145789.846439e-09
0.6212291.5144639.896908e-09
0.6244151.5143499.947635e-09
0.6276171.5142369.998622e-09
0.6308361.5141241.004987e-08
0.6340711.5140131.010138e-08
0.6373231.5139021.015316e-08
0.6405921.5137931.020520e-08
0.6438771.5136841.025751e-08
0.6471791.5135771.031008e-08
0.651.5134861.035500e-08
0.6504981.513471.036294e-08
0.6538341.5133641.041612e-08
0.6571871.5132591.046957e-08
0.6605581.5131541.052329e-08
0.6639451.5130511.057729e-08
0.6673511.5129481.063157e-08
0.6707731.5128461.068612e-08
0.6742131.5127451.074096e-08
0.6776711.5126451.079607e-08
0.6811461.5125451.085147e-08
0.684641.5124461.090715e-08
0.6881511.5123481.096312e-08
0.691681.512251.101938e-08
0.6952271.5121531.107592e-08
0.6987931.5120571.113276e-08
0.71.5120251.115200e-08
0.7023761.5119621.118986e-08
0.7059791.5118671.124724e-08
0.7095991.5117731.130492e-08
0.7132381.5116791.136289e-08
0.7168961.5115861.142116e-08
0.7205731.5114941.147973e-08
0.7242681.5114021.153860e-08
0.7279831.5113111.159777e-08
0.7317161.5112211.165724e-08
0.7354691.5111311.171702e-08
0.7392411.5110411.177711e-08
0.7430321.5109521.183750e-08
0.7468431.5108641.189820e-08
0.7506731.5107761.195922e-08
0.7545231.5106891.202055e-08
0.7583921.5106021.208219e-08
0.7622821.5105161.214415e-08
0.7661911.5104311.220642e-08
0.770121.5103451.226902e-08
0.774071.5102611.233194e-08
0.778041.5101761.239517e-08
0.782031.5100921.245874e-08
0.7860411.5100091.252263e-08
0.7900721.5099261.258685e-08
0.7941241.5098441.265139e-08
0.7981961.5097611.271627e-08
0.81.5097251.274500e-08
0.802291.509681.278150e-08
0.8064051.5095981.284709e-08
0.810541.5095171.291301e-08
0.8146971.5094371.297927e-08
0.8188751.5093571.304587e-08
0.8230751.5092771.311281e-08
0.8272961.5091971.318010e-08
0.8315391.5091181.324773e-08
0.8358031.509041.331571e-08
0.840091.5089611.338403e-08
0.8443981.5088831.345271e-08
0.8487291.5088051.352174e-08
0.851.5087821.354200e-08
0.8530821.5087281.359106e-08
0.8574571.508651.366071e-08
0.8618541.5085731.373072e-08
0.8662741.5084971.380108e-08
0.8707171.508421.387181e-08
0.8751821.5083441.394290e-08
0.8796711.5082681.401436e-08
0.8841821.5081921.408618e-08
0.8887171.5081171.415837e-08
0.8932741.5080421.423093e-08
0.8978561.5079671.430386e-08
0.91.5079321.433800e-08
0.902461.5078921.437722e-08
0.9070881.5078171.445099e-08
0.9117411.5077431.452514e-08
0.9164161.5076681.459968e-08
0.9211161.5075941.467459e-08
0.925841.507521.474989e-08
0.9305881.5074471.482558e-08
0.9353611.5073731.490165e-08
0.9401581.5072991.497812e-08
0.944981.5072261.505497e-08
0.9498261.5071531.513222e-08
0.951.507151.513500e-08
0.9546971.507081.520978e-08
0.9595931.5070071.528772e-08
0.9645151.5069341.536607e-08
0.9694611.5068611.544482e-08
0.9744331.5067881.552397e-08
0.979431.5067151.560353e-08
0.9844531.5066431.568350e-08
0.9895021.506571.576387e-08
0.9945771.5064981.584466e-08
0.9996781.5064251.592587e-08
11.5064211.593100e-08
1.00481.5063531.600755e-08
1.009961.506281.608966e-08
1.015141.5062081.617219e-08
1.020341.5061351.625514e-08
1.025581.5060631.633851e-08
1.030841.5059911.642232e-08
1.036121.5059181.650655e-08
1.041441.5058461.659122e-08
1.046781.5057731.667632e-08
1.052151.5057011.676185e-08
1.057541.5056281.684783e-08
1.061.5055951.688700e-08
1.062971.5055551.693425e-08
1.068421.5054831.702113e-08
1.07391.505411.710844e-08
1.07941.5053371.719621e-08
1.084941.5052641.728443e-08
1.09051.5051911.737309e-08
1.09611.5051181.746222e-08
1.101721.5050451.755180e-08
1.107371.5049711.764184e-08
1.113051.5048981.773234e-08
1.118761.5048241.782330e-08
1.124491.504751.791474e-08
1.130261.5046761.800664e-08
1.136061.5046021.809901e-08
1.141881.5045281.819185e-08
1.147741.5044531.828518e-08
1.153621.5043791.837898e-08
1.159541.5043041.847326e-08
1.165491.5042291.856802e-08
1.171471.5041531.866328e-08
1.177471.5040781.875902e-08
1.183511.5040021.885525e-08
1.189581.5039261.895197e-08
1.195681.503851.904919e-08
1.21.5037961.911800e-08
1.201811.5037732.129605e-08
1.207981.5036962.869573e-08
1.214171.5036193.613335e-08
1.22041.5035424.360913e-08
1.226661.5034655.112324e-08
1.232951.5033875.867589e-08
1.239271.5033086.626727e-08
1.245631.503237.389758e-08
1.252021.5031518.156703e-08
1.258441.5030728.927581e-08
1.264891.5029929.702412e-08
1.271381.5029121.048122e-07
1.27791.5028321.126402e-07
1.284451.5027511.205083e-07
1.291041.502671.284168e-07
1.297661.5025891.363658e-07
1.304321.5025071.443557e-07
1.311011.5024251.523864e-07
1.317731.5023421.604584e-07
1.324491.5022591.685718e-07
1.331281.5021761.767268e-07
1.338111.5020921.849236e-07
1.344971.5020071.931624e-07
1.351871.5019232.014435e-07
1.35881.5018372.097671e-07
1.365771.5017512.181334e-07
1.372771.5016652.265425e-07
1.379811.5015782.349948e-07
1.386891.5014912.434904e-07
1.3941.5014032.520297e-07
1.41.5013292.592300e-07
1.401151.5013152.582523e-07
1.408341.5012262.521519e-07
1.415561.5011362.460202e-07
1.422821.5010462.398570e-07
1.430121.5009552.336623e-07
1.437451.5008642.274358e-07
1.444821.5007722.211773e-07
1.452231.500682.148868e-07
1.459681.5005872.085640e-07
1.467171.5004932.022087e-07
1.474691.5003991.958209e-07
1.482251.5003041.894003e-07
1.489861.5002081.829468e-07
1.49751.5001121.764602e-07
1.505181.5000151.699403e-07
1.51291.4999171.633870e-07
1.520651.4998191.568001e-07
1.528451.4997191.501794e-07
1.536291.499621.435247e-07
1.544171.4995191.368359e-07
1.552091.4994181.301128e-07
1.560051.4993151.233552e-07
1.568051.4992121.165630e-07
1.576091.4991091.097359e-07
1.584181.4990041.028739e-07
1.59231.4988999.597659e-08
1.61.4987998.944000e-08
1.600471.4987938.966857e-08
1.608671.4986869.369009e-08
1.616921.4985789.773223e-08
1.625221.4984691.017951e-07
1.633551.4983591.058788e-07
1.641931.4982491.099835e-07
1.650351.4981371.141092e-07
1.658811.4980251.182560e-07
1.667321.4979121.224242e-07
1.675871.4977971.266137e-07
1.684471.4976821.308247e-07
1.693111.4975661.350572e-07
1.701791.4974491.393115e-07
1.710521.4973311.435877e-07
1.719291.4972111.478857e-07
1.728111.4970911.522058e-07
1.736971.496971.565480e-07
1.745881.4968471.609125e-07
1.754831.4967241.652994e-07
1.763831.4965991.697088e-07
1.772881.4964741.741408e-07
1.781971.4963471.785956e-07
1.791111.4962191.830731e-07
1.81.4960941.874300e-07
1.800291.496091.877700e-07
1.809531.495961.984731e-07
1.818811.4958282.092312e-07
1.828131.4956962.200444e-07
1.837511.4955622.309131e-07
1.846931.4954262.418375e-07
1.856411.495292.528179e-07
1.865931.4951522.638547e-07
1.87551.4950132.749481e-07
1.885111.4948732.860983e-07
1.894781.4947322.973058e-07
1.90451.4945893.085707e-07
1.914271.4944443.198934e-07
1.924081.4942993.312741e-07
1.933951.4941513.427132e-07
1.943871.4940033.542110e-07
1.953841.4938533.657678e-07
1.963861.4937013.773838e-07
1.973931.4935493.890594e-07
1.984051.4933944.007949e-07
1.994231.4932384.125905e-07
21.4931494.192800e-07
2.004461.4930814.580402e-07
2.014741.4929225.474403e-07
2.025071.4927616.372988e-07
2.035461.4925997.276182e-07
2.045891.4924358.184009e-07
2.056391.4922699.096490e-07
2.066931.4921021.001365e-06
2.077531.4919331.093552e-06
2.088191.4917631.186211e-06
2.09891.491591.279346e-06
2.109661.4914161.372958e-06
2.120481.491241.467050e-06
2.131361.4910631.561625e-06
2.142291.4908831.656685e-06
2.153271.4907021.752232e-06
2.164321.4905191.848269e-06
2.175421.4903331.944799e-06
2.186571.4901462.041824e-06
2.197791.4899572.139347e-06
2.21.489922.158600e-06
2.209061.4897662.223049e-06
2.220391.4895732.303661e-06
2.231771.4893782.384688e-06
2.243221.4891812.466129e-06
2.254721.4889822.547989e-06
2.266291.488782.630268e-06
2.277911.4885772.712969e-06
2.289591.4883712.796095e-06
2.301331.4881632.879646e-06
2.313141.4879532.963627e-06
2.3251.4877413.048037e-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
—