Far-field scattering simulation for bulk scatterers

Importing the package dependencies: numpy, PyMieSim

from TypedUnit import ureg
import numpy
import matplotlib.pyplot as plt
from PyMieSim.experiment.scatterer import Sphere
from PyMieSim.experiment.source import Gaussian
from PyMieSim.experiment import Setup
from PyMieSim.single.polarization import RightCircular
from PyOptik import Material
from PyMieSim.single.mesh import FibonacciMesh
from PyMieSim.utils import spherical_to_cartesian

Defining the source to be employed.

source = Gaussian(
    wavelength=1200 * ureg.nanometer,
    polarization=RightCircular(),
    optical_power=1e-3 * ureg.watt,
    NA=0.2 * ureg.AU,
)

Defining the ranging parameters for the scatterer distribution

scatterer = Sphere(
    diameter=[800, 1000, 1200] * ureg.nanometer,
    property=Material.BK7,
    medium_property=1 * ureg.RIU,
    source=source,
)

Defining the detector to be employed.

mesh = FibonacciMesh(
    sampling=1400,
    max_angle=80 * ureg.degree,
    min_angle=0 * ureg.degree,
    phi_offset=0 * ureg.radian,
    gamma_offset=0 * ureg.radian,
)

Defining the experiment setup

experiment = Setup(scatterer=scatterer, source=source)

Measuring the properties

farfields = experiment.binding._get_farfields(
    scatterer_set=experiment.scatterer.set,
    source_set=experiment.source.set,
    mesh=mesh,
).squeeze()


spf = numpy.einsum("ijk->ik", abs(farfields) ** 2)


figure, axes = plt.subplots(
    ncols=3,
    nrows=1,
    figsize=(12, 4),
    subplot_kw={"projection": "3d"},
    sharex=True,
    sharey=True,
)


for idx, ax in enumerate(axes):

    x, y, z = spherical_to_cartesian(
        phi=mesh.spherical.phi,
        theta=mesh.spherical.theta,
        r=spf[idx],
    )

    ax.scatter(x, y, z)
    spf_min, spf_max = spf.min(), spf.max()
    ax.set(
        xlim=(-spf_max, spf_max),
        ylim=(-spf_max, spf_max),
        zlim=(-spf_max, spf_max),
    )


plt.show()