Refractive index of Surlyn A-1601

import lightsmith as ls

# Surlyn A-1601: Smith and Loewenstein 1975: n,k 28.6–200 µm
surlyna1601 = ls.fetch_refractiveindex("other", "SurlynA1601", "Smith", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(surlyna1601.range_nm)  # (28571.4, 200000) nm
eps = surlyna1601.eps([75600])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_fbef17a1a866/lightsmith"
surlyna1601 = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(surlyna1601.source)  # citation and provenance travel with the data

# ... load surlyna1601 as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=surlyna1601)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=28570, stop_nm=200000, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength