Cylinder: Qabs vs Diameter

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

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 PyOptik import Material
from PyMieSim.units import nanometer, degree, watt, AU, RIU

Defining the source

source = Gaussian(
    wavelength=400 * nanometer,  # 400 nm
    polarization=0 * degree,  # Linear polarization angle in radians
    optical_power=1e-3 * watt,  # 1 milliwatt
    NA=0.2 * AU  # Numerical Aperture
)

Defining the scatterer distribution

scatterer = Cylinder(
    diameter=np.linspace(1, 800, 300) * nanometer,  # Diameters ranging from 1 nm to 800 nm
    property=[Material.silver, Material.gold, Material.aluminium],  # Scatterer materials
    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) Note: The original request mentioned Qsca, but the measurement code uses Qabs. If Qsca measurement is intended, ensure to use the correct measure object from PyMieSim.

dataframe = experiment.get('Qabs')  # Assuming Qabs was intended, replace with measure.Qsca if needed

Plotting the results Visualizing how the scattering efficiency varies with the cylinder diameter.

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

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