Refractive index of GaN (Gallium nitride)

import lightsmith as ls

# GaN (Gallium nitride): Kawashima et al. 1997: thin film; n,k 0.124–0.992 µm
gan = ls.fetch_refractiveindex("main", "GaN", "Kawashima", ref="c5c2f188e848453def5970e347399d653df2ffc2")
print(gan.range_nm)  # (123.98, 991.87) nm
eps = gan.eps([633])  # complex permittivity

import json, urllib.request
import lightsmith as ls

url = "https://materials.lightsmith.dev/v1/datasets/ds_e52cd3a0d2a8/lightsmith"
gan = ls.Tabulated.model_validate(json.load(urllib.request.urlopen(url)))
print(gan.source)  # citation and provenance travel with the data

# ... load gan as above, then:
sim = ls.Simulation(
    particles=[ls.Particle(shape=ls.Sphere(radius_nm=50), material=gan)],
    medium_index=1.0,
    wavelengths=ls.WavelengthRange(start_nm=400, stop_nm=991, num=81),
)
res = ls.solve(sim)  # exact Mie for a sphere
print(res.q_ext)     # extinction efficiency at each wavelength