Refractive index of K-PBK40(M) (SUMITA)

import lightsmith as ls

# K-PBK40(M) (SUMITA): K-PBK40(M)
sumita_k_pbk40_m = ls.fetch_refractiveindex("specs", "SUMITA-optical", "K-PBK40(M)", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(sumita_k_pbk40_m.range_nm)  # (360, 1550) nm
eps = sumita_k_pbk40_m.eps([633])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_6eac91f44b86/lightsmith"
sumita_k_pbk40_m = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(sumita_k_pbk40_m.source)  # citation and provenance travel with the data

# ... load sumita_k_pbk40_m as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=sumita_k_pbk40_m)],
    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