Cylinder: Qsca vs Diameter

This example demonstrates how to compute and visualize the scattering efficiency (Qsca) as a function of diameter for cylindrical scatterers using PyMieSim, considering multiple wavelengths.

Importing the package dependencies: numpy, PyMieSim

import numpy as np
from PyMieSim.experiment.scatterer import Cylinder
from PyMieSim.experiment.source import Gaussian
from PyMieSim.experiment import Setup
from PyMieSim.units import nanometer, degree, watt, AU, RIU

Defining the source

source = Gaussian(
    wavelength=[500, 1000, 1500] * nanometer,  # Array of wavelengths: 500 nm, 1000 nm, 1500 nm
    polarization=30 * degree,  # Polarization angle in degrees
    optical_power=1e-3 * watt,  # 1 milliwatt
    NA=0.2 * AU  # Numerical Aperture
)

Defining the scatterer distribution

scatterer = Cylinder(
    diameter=np.geomspace(6.36, 10000, 1000) * nanometer,  # Diameters ranging from ~6.36 nm to 10000 nm
    property=[1.4] * RIU,  # Refractive index of the cylinder
    medium_property=1 * RIU,  # Refractive index of the surrounding medium
    source=source
)

Setting up the experiment

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

Measuring the scattering efficiency (Qsca)

dataframe = experiment.get('Qsca')

Plotting the results Visualizing how the Qsca varies with the cylinder diameter.

dataframe.plot_data(x='scatterer:diameter')

<Axes: xlabel='nanometer', ylabel='dimensionless'>