Refractive index of Ta₂O₅ (Tantalum pentoxide)

import lightsmith as ls

# Ta2O5 (Tantalum pentoxide): Franta et al. 2025: Polycrystalline; n,k 0.116–400 µm
ta2o5 = ls.fetch_refractiveindex("main", "Ta2O5", "Franta-2025", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(ta2o5.range_nm)  # (115.976, 400286) nm
eps = ta2o5.eps([633])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_8d0169078be3/lightsmith"
ta2o5 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(ta2o5.source)  # citation and provenance travel with the data

# ... load ta2o5 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=ta2o5)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=1000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength