.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "gallery/interpretation/scattering_absorption_resonances.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_gallery_interpretation_scattering_absorption_resonances.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_gallery_interpretation_scattering_absorption_resonances.py:


Separate scattering and absorption resonances
=============================================

A peak in extinction does not by itself say where the removed incident power
goes. This wavelength scan separates ``Qext`` into ``Qsca`` and ``Qabs`` for a
lossy sphere. The lower panel shows the single-scattering albedo
``Qsca / Qext``: values near one indicate that extinction is dominated by
scattering, while lower values indicate a larger absorbed fraction.

The calculation concerns one isolated sphere. Peak locations depend on the
particle size, complex refractive index, surrounding medium, and any material
dispersion included in the model.

.. GENERATED FROM PYTHON SOURCE LINES 15-62



.. image-sg:: /gallery/interpretation/images/sphx_glr_scattering_absorption_resonances_001.png
   :alt: Extinction combines scattered and absorbed power, Single-scattering albedo
   :srcset: /gallery/interpretation/images/sphx_glr_scattering_absorption_resonances_001.png
   :class: sphx-glr-single-img





.. code-block:: Python

    import matplotlib.pyplot as plt
    import numpy as np

    from PyMieSim import Measure, PlaneWave, PolarizationState, Simulation, Sphere, ureg

    wavelengths = np.linspace(350, 1000, 260)
    qsca = np.empty_like(wavelengths)
    qabs = np.empty_like(wavelengths)
    qext = np.empty_like(wavelengths)

    for index, wavelength in enumerate(wavelengths):
        source = PlaneWave(
            wavelength=wavelength * ureg.nanometer,
            polarization=PolarizationState(angle=0 * ureg.degree),
            amplitude=1 * ureg.volt / ureg.meter,
        )
        simulation = Simulation(
            scatterer=Sphere(
                diameter=420 * ureg.nanometer,
                material=1.65 + 0.08j,
                medium=1.33,
            ),
            source=source,
        )
        measures = simulation.get(Measure.QSCA, Measure.QABS, Measure.QEXT)
        qsca[index] = measures["Qsca"].magnitude
        qabs[index] = measures["Qabs"].magnitude
        qext[index] = measures["Qext"].magnitude

    single_scattering_albedo = qsca / qext

    figure, axes = plt.subplots(2, 1, figsize=(8, 6.5), sharex=True, height_ratios=(2, 1))
    axes[0].plot(wavelengths, qext, color="black", linewidth=2.2, label="Qext")
    axes[0].plot(wavelengths, qsca, linewidth=2, label="Qsca")
    axes[0].plot(wavelengths, qabs, linewidth=2, label="Qabs")
    axes[0].set(ylabel="Efficiency", title="Extinction combines scattered and absorbed power")
    axes[0].legend()
    axes[1].plot(wavelengths, single_scattering_albedo, color="tab:green", linewidth=2)
    axes[1].set(
        xlabel="Vacuum wavelength [nm]",
        ylabel="Qsca / Qext",
        ylim=(0, 1.05),
        title="Single-scattering albedo",
    )
    for axis in axes:
        axis.grid(alpha=0.2)
    plt.show()


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.211 seconds)


.. _sphx_glr_download_gallery_interpretation_scattering_absorption_resonances.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: scattering_absorption_resonances.ipynb <scattering_absorption_resonances.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: scattering_absorption_resonances.py <scattering_absorption_resonances.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: scattering_absorption_resonances.zip <scattering_absorption_resonances.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_