Refractive index of Au-Ag (Gold-silver alloy)

import lightsmith as ls

# Au-Ag (Gold-silver alloy): Rioux et al. 2014: n,k 0.27–1.2 µm; 60% Au 40% Ag
au_ag = ls.fetch_refractiveindex("other", "Au-Ag", "Rioux-Au60Ag40", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(au_ag.range_nm)  # (270, 1200) nm
eps = au_ag.eps([633])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_4c7ab902128e/lightsmith"
au_ag = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(au_ag.source)  # citation and provenance travel with the data

# ... load au_ag as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=au_ag)],
    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