:orphan:

Plotting the far field
======================

This example contains the simulation of a plane wave scattered by a spiral of fifteen glass spheres on a glass substrate under oblique incidence. 
Click :download:`here <../../../../examples/tutorials/03_plotting_the_far_field/fifteen_spheres_on_substrate.py>` 
to download the Python script.

.. list-table::

    * - .. figure:: top_2d.png

           ambient DSCS

      - .. figure:: top_1d.png

           ambient DSCS (integrated over :math:`\alpha`)
					 
    * - .. figure:: bottom_2d.png

           substrate DSCS

      - .. figure:: bottom_1d.png

           substrate DSCS (integrated over :math:`\alpha`)

After the simulation has run, the differential scattering cross section is evaluated in a post processing step.
The left column shows the 2D-differential scattering cross section, :math:`\mathrm{DSCS}(\alpha, \beta) = \frac{\mathrm{dSCS}}{\mathrm{d}\Omega}`,
whereas the right column shows the 1D distribution (i.e., the integral over the azimuthal direction coordinate), :math:`\mathrm{DSCS}(\beta) = \frac{\mathrm{dSCS}}{\mathrm{d}\cos\beta}`.

In the substrate far field, the critical angle is visible as a ring-shaped feature.

Click on the following link to view the API documentation of the function that is used to calculate and plot the fields.
:py:func:`smuthi.postprocessing.graphical_output.show_scattering_cross_section`