Optical constants
Refractive index of PtSe2 (Platinum diselenide)
Tharrault et al. 2025: 10L film; n,k 0.416–1.55 µm
- Data
- tabulated nk
- Range
- 0.416–1.55 µm
- Points
- 109
- State
- crystalline
- Licence
- CC0-1.0
Plot
Click the plot to set the calculator wavelength.
At one wavelength
- Refractive index n
- 4.4607
- Extinction coefficient k
- 2.8673
- Permittivity ε1
- 11.6765
- Permittivity ε2
- 25.5803
- Absorption coefficient α
- 613198 cm⁻¹
- Penetration depth δ = λ/(2πk)
- 32.6159 nm
- Abbe number Vd
- —
- Chromatic dispersion dn/dλ
- 2.52783 µm⁻¹
- Group index ng
- 2.97535
- 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
# PtSe2 (Platinum diselenide): Tharrault et al. 2025: 10L film; n,k 0.416–1.55 µm
ptse2 = ls.fetch_refractiveindex("main", "PtSe2", "Tharrault-10L", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ptse2.range_nm) # (416.05, 1550.38) nm
eps = ptse2.eps([633]) # complex permittivity
Downloads 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_cfe9ea588348/lightsmith"
ptse2 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(ptse2.source) # citation and provenance travel with the data
Any dataset here, as the library's Tabulated material (ptse2/tharrault-2025-10l).
# ... load ptse2 as above, then:
sim = ls.Simulation(
particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=ptse2)],
medium_index=1.0,
wavelengths=ls.WavelengthRange(start_nm=417, stop_nm=1000, num=81),
)
res = ls.solve(sim) # exact Mie for a sphere
print(res.q_ext) # extinction efficiency at each wavelength
Same 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
References
- doi:10.1103/physrevlett.134.066901 Optical Absorption in Indirect Semiconductor to Semimetal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>PtSe</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> Arises from Direct Transitions, Physical Review Letters (2025)
Cite
Marin Tharrault et al.. Optical Absorption in Indirect Semiconductor to Semimetal <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>PtSe</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> Arises from Direct Transitions. Physical Review Letters, 134, 066901 (2025), doi:10.1103/physrevlett.134.066901; Data from the refractiveindex.info database (M. N. Polyanskiy, Sci. Data 11, 94 (2024), doi:10.1038/s41597-023-02898-2)
Data
109 rows as published| λ (µm) | n | k |
|---|---|---|
| 0.41605 | 4.25436 | 2.10426 |
| 0.41887 | 4.22011 | 2.14187 |
| 0.42171 | 4.21731 | 2.17192 |
| 0.4246 | 4.201 | 2.20632 |
| 0.42753 | 4.17904 | 2.26034 |
| 0.4305 | 4.17728 | 2.2963 |
| 0.43351 | 4.21079 | 2.28913 |
| 0.43656 | 4.2139 | 2.31325 |
| 0.43966 | 4.19506 | 2.36465 |
| 0.4428 | 4.19421 | 2.40509 |
| 0.44599 | 4.19051 | 2.4511 |
| 0.44922 | 4.18039 | 2.49831 |
| 0.4525 | 4.18859 | 2.52511 |
| 0.45582 | 4.18724 | 2.56318 |
| 0.4592 | 4.19007 | 2.57871 |
| 0.46263 | 4.19582 | 2.60816 |
| 0.46611 | 4.20485 | 2.62904 |
| 0.46964 | 4.2047 | 2.66126 |
| 0.47322 | 4.21533 | 2.67831 |
| 0.47686 | 4.22707 | 2.69318 |
| 0.48056 | 4.2439 | 2.70152 |
| 0.48431 | 4.23004 | 2.74584 |
| 0.48813 | 4.24479 | 2.75067 |
| 0.492 | 4.25535 | 2.7566 |
| 0.49594 | 4.25284 | 2.77665 |
| 0.49994 | 4.27723 | 2.76667 |
| 0.504 | 4.27763 | 2.77604 |
| 0.50813 | 4.27221 | 2.79677 |
| 0.51233 | 4.28229 | 2.79645 |
| 0.5166 | 4.27609 | 2.81441 |
| 0.52094 | 4.2851 | 2.81692 |
| 0.52536 | 4.28938 | 2.82458 |
| 0.52985 | 4.29669 | 2.83041 |
| 0.53441 | 4.31222 | 2.83099 |
| 0.53906 | 4.31906 | 2.83551 |
| 0.54379 | 4.32781 | 2.84283 |
| 0.5486 | 4.34427 | 2.8453 |
| 0.5535 | 4.36208 | 2.84314 |
| 0.55849 | 4.36941 | 2.85597 |
| 0.56356 | 4.3955 | 2.84282 |
| 0.56873 | 4.40808 | 2.85065 |
| 0.574 | 4.42236 | 2.8556 |
| 0.57937 | 4.45253 | 2.84449 |
| 0.58483 | 4.4537 | 2.86237 |
| 0.5904 | 4.46778 | 2.87228 |
| 0.59608 | 4.50249 | 2.86308 |
| 0.60187 | 4.5045 | 2.90835 |
| 0.60777 | 4.5197 | 2.92069 |
| 0.61378 | 4.53863 | 2.93309 |
| 0.61992 | 4.54085 | 2.97801 |
| 0.62618 | 4.56025 | 2.99744 |
| 0.63257 | 4.59673 | 3.00829 |
| 0.63909 | 4.59112 | 3.06039 |
| 0.64575 | 4.65098 | 3.0633 |
| 0.65255 | 4.68972 | 3.07432 |
| 0.65949 | 4.70888 | 3.10313 |
| 0.66658 | 4.7033 | 3.16675 |
| 0.67383 | 4.73244 | 3.19257 |
| 0.68123 | 4.75505 | 3.24136 |
| 0.6888 | 4.86337 | 3.18008 |
| 0.69654 | 4.89324 | 3.20728 |
| 0.70446 | 4.9336 | 3.22833 |
| 0.71255 | 5.03505 | 3.18419 |
| 0.72084 | 5.07271 | 3.20617 |
| 0.72932 | 5.12016 | 3.22049 |
| 0.738 | 5.14418 | 3.2369 |
| 0.74689 | 5.17123 | 3.28581 |
| 0.756 | 5.25263 | 3.28332 |
| 0.76533 | 5.29476 | 3.33349 |
| 0.7749 | 5.41199 | 3.31545 |
| 0.78471 | 5.50315 | 3.33518 |
| 0.79477 | 5.60163 | 3.35619 |
| 0.80509 | 5.69908 | 3.38793 |
| 0.81569 | 5.818 | 3.38204 |
| 0.82656 | 5.93174 | 3.38968 |
| 0.83773 | 6.08383 | 3.32167 |
| 0.84921 | 6.20873 | 3.26529 |
| 0.861 | 6.28392 | 3.224 |
| 0.87313 | 6.44583 | 3.07737 |
| 0.8856 | 6.52737 | 2.9638 |
| 0.89844 | 6.63386 | 2.82324 |
| 0.91165 | 6.71667 | 2.68754 |
| 0.92526 | 6.74882 | 2.58845 |
| 0.93927 | 6.8011 | 2.42214 |
| 0.95372 | 6.80889 | 2.37354 |
| 0.96863 | 6.78653 | 2.29831 |
| 0.984 | 6.62022 | 2.23597 |
| 0.99987 | 6.63024 | 2.11894 |
| 1.01626 | 6.63953 | 1.97942 |
| 1.0332 | 6.66471 | 1.89717 |
| 1.06883 | 6.54203 | 1.57213 |
| 1.08758 | 6.59918 | 1.492 |
| 1.107 | 6.5698 | 1.38293 |
| 1.12713 | 6.51896 | 1.30764 |
| 1.148 | 6.48806 | 1.19574 |
| 1.16966 | 6.41015 | 1.14798 |
| 1.19216 | 6.39221 | 1.0418 |
| 1.21553 | 6.35217 | 0.97547 |
| 1.24021 | 6.29955 | 0.94737 |
| 1.26553 | 6.27076 | 0.88865 |
| 1.29191 | 6.23046 | 0.82924 |
| 1.3194 | 6.18457 | 0.77361 |
| 1.34809 | 6.15075 | 0.74041 |
| 1.37806 | 6.10485 | 0.70867 |
| 1.40939 | 6.04553 | 0.68314 |
| 1.44218 | 6.01595 | 0.63552 |
| 1.47653 | 5.9909 | 0.59646 |
| 1.51256 | 5.96556 | 0.5424 |
| 1.55038 | 5.96132 | 0.49549 |
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
- —
10L CVT-grown exfoliated crystal. The optical indexes are computed from the 2D surface conductivity using σ2D·Z0 = −2πi·(t/λ)·(εr−1), where Z0 is the impedance of free space, i the imaginary unit, t the equivalent layered stack thickness and λ the free space wavelength. We use t = NL t0 with t0 = 5.1 Å the single layer thickness. The measurement method accuratly determines Im{εr} = 2nk, but only Re{εr} = n2 - k2 as long as the optical absorption is non-zero.