Optical constants
Refractive index of TlBr42I58 - KRS5 (CRYSTRAN)
TlBr42I58 - KRS5: n,k 0.54–40 µm
- Data
- tabulated n + tabulated k
- Range
- 0.54–40 µm
- Points
- 42
- Licence
- CC0-1.0
Plot
Click the plot to set the calculator wavelength. Note: k data cover 556-24600 nm only; k = 0 elsewhere in the n range 540-40000 nm.
At one wavelength
- Refractive index n
- 2.65634
- Extinction coefficient k
- 8.49400e-07
- Permittivity ε1
- 7.05612
- Permittivity ε2
- 4.51258e-06
- Absorption coefficient α
- 0.181652 cm⁻¹
- Penetration depth δ = λ/(2πk)
- 1.10101e+08 nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- -0.509543 µm⁻¹
- Group index ng
- 2.95574
- Group velocity dispersion
- — fs²/mm
- Dispersion parameter D
- — 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
# TlBr42I58 - KRS5 (CRYSTRAN): TlBr42I58 - KRS5
crystran_krs5 = ls.fetch_refractiveindex("specs", "CRYSTRAN-optical", "KRS5", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(crystran_krs5.range_nm) # (540, 40000) nm
eps = crystran_krs5.eps([633]) # complex permittivityDownloads the original record once (pinned to the imported snapshot) and caches it.
import json, urllib.request
import lightsmith as ls
url = "https://materials.lightsmith.dev/v1/datasets/ds_6897435e8100/lightsmith"
crystran_krs5 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(crystran_krs5.source) # citation and provenance travel with the dataAny dataset here, as the library's Tabulated material (crystran-krs5/crystran).
# ... load crystran_krs5 as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=crystran_krs5)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=540, stop_nm=1000, num=81),
)
res = ls.solve(sim) # exact Mie for a sphere
print(res.q_ext) # extinction efficiency at each wavelengthSame spec runs with DDA, FDTD, BEM or T-matrix: ls.compare(sim, ["mie", "dda"]).
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.
Comments and conditions
Properties
- density
- value: 7371
- thermal dispersion
- type: constant, value: -235e-06
- thermal expansion
- value: 58e-06
- hardness
- type: Knoop, value: 3.94e8
- melting point
- value: 688
- thermal conductivity
- value: 0.544, temperature: 293
- youngs modulus
- value: 15.85e9
- poissons ratio
- value: 0.369
- solubility
- value: 0.5, temperature: 293
Thermo-optic coefficient
- dn/dT = -0.000235 K⁻¹
- k data cover 556-24600 nm only; k = 0 elsewhere in the n range 540-40000 nm
References
See also Crystran KRS5 online data sheet
Cite
Crystran Ltd. The Crystran handbook of infra-red and ultra-violet optical materials (5th edition, 2023); See also Crystran KRS5 online data sheet; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
Computed on 42 wavelengths, the same grid as the API and the library| λ (µm) | n | k |
|---|---|---|
| 0.54 | 2.68059 | 0 |
| 1 | 2.4462 | 1.418706e-07 |
| 1.5 | 2.40774 | 9.904706e-08 |
| 2 | 2.39498 | 5.622353e-08 |
| 3 | 2.38574 | 1.950000e-07 |
| 4 | 2.38204 | 1.710000e-07 |
| 5 | 2.37979 | 3.550000e-07 |
| 6 | 2.37797 | 6.100000e-07 |
| 7 | 2.37627 | 8.260000e-07 |
| 8 | 2.37452 | 7.180000e-07 |
| 9 | 2.37267 | 6.410000e-07 |
| 10 | 2.37069 | 8.490000e-07 |
| 11 | 2.36854 | 1.110000e-06 |
| 12 | 2.36622 | 1.190000e-06 |
| 13 | 2.36371 | 1.220000e-06 |
| 14 | 2.36101 | 1.280000e-06 |
| 15 | 2.3581 | 1.370000e-06 |
| 16 | 2.35502 | 1.490000e-06 |
| 17 | 2.35173 | 1.260000e-06 |
| 18 | 2.34822 | 9.620000e-07 |
| 19 | 2.34451 | 8.270000e-07 |
| 20 | 2.34058 | 5.320000e-07 |
| 21 | 2.33643 | 1.020000e-06 |
| 22 | 2.33206 | 9.420000e-07 |
| 23 | 2.32746 | 1.990000e-06 |
| 24 | 2.32264 | 4.490000e-06 |
| 25 | 2.31758 | 0 |
| 26 | 2.31229 | 0 |
| 27 | 2.30676 | 0 |
| 28 | 2.30098 | 0 |
| 29 | 2.29495 | 0 |
| 30 | 2.28867 | 0 |
| 31 | 2.28212 | 0 |
| 32 | 2.27531 | 0 |
| 33 | 2.26823 | 0 |
| 34 | 2.26087 | 0 |
| 35 | 2.25322 | 0 |
| 36 | 2.24528 | 0 |
| 37 | 2.23705 | 0 |
| 38 | 2.2285 | 0 |
| 39 | 2.21965 | 0 |
| 40 | 2.21047 | 0 |
Optical transmission calculator
Free-standing sample in vacuum, normal incidence- Transmittance T
- —
- Reflectance R
- —
Fresnel reflection calculator
- Rp
- —
- Rs
- —
- R = (Rp+Rs)/2
- —
- Phase φp
- —
- Phase φs
- —
- Brewster angle θB
- —
- Critical angle θC
- —
TlBr42I58 KRS5 deep IR material with a high refractive index, KRS5 is used extensively in spectroscopy for ATR prisms, windows and lenses. In conjunction with Germanium, KRS5 can also be used in athermalised IR imaging systems.
KRS-5 crystalises by the sealed-ampoule Stockbarger technique. Starting materials of the highest purity are selected to ensure that there are no anionic absorption bands between 2μm and 16μm and all crystals are checked for quality by using a pathlength of 120mm.
CAUTION: Thallium salts are considered TOXIC and should be handled with care.
REFERENCES:
(1) Rodney and Malitson J.Opt Soc.Am. V46, p 956, 1953
(2) Combes, Ballard, McCarthy: J.Opt Soc.Am. V41, p 215, 1951
(3) Handbook of Optical Constants, ed Palik, V3, ISBN 0-12-544423-0