.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_tutorials/free_space/plot_02_cartesian.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

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

        :ref:`Go to the end <sphx_glr_download_auto_tutorials_free_space_plot_02_cartesian.py>`
        to download the full example code.

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

.. _sphx_glr_auto_tutorials_free_space_plot_02_cartesian.py:


A Cartesian beam in argon
=========================

A weak pulsed beam on a Cartesian transverse grid: 800 nm, 30 fs, 1.5 nJ, a 2 mm
waist and argon at 4 bar. The energy is the physical energy crossing the entrance plane
in the argon (:doc:`/guide/free-space/flux`). The calculation is reduced to a 32 by 40
grid and a 20 mm distance to keep it short.

.. GENERATED FROM PYTHON SOURCE LINES 14-27

.. code-block:: Python


    import matplotlib.pyplot as plt
    import numpy as np

    from solprop.driver import SimulationSettings, prop_free
    from solprop.grid import EnvelopeGrid, FreeGrid
    from solprop.nonlinear.responses import KerrResponse
    from solprop.physdata import gamma3
    from solprop.pulses import GaussianPulse, SpatialPulse
    from solprop.spatial import SpatialFlux, SpatialMedium, spatial_fluence
    from solprop.stats import StatsSpec
    from solprop.stepper import PIController








.. GENERATED FROM PYTHON SOURCE LINES 28-31

A matched envelope of the weak field pulse makes the geometry easy to inspect.
Each Cartesian component has its own transverse FFT; fields are in V/m.
The axes name x first; reshaping flattened columns puts x on the last axis.

.. GENERATED FROM PYTHON SOURCE LINES 31-62

.. code-block:: Python

    length = 0.02
    grid = EnvelopeGrid.from_limits(length, 800e-9, (400e-9, 2e-6), 200e-15, thg=False)
    space = FreeGrid(6e-3, 32, 7.5e-3, 40)
    argon = SpatialMedium("Ar", pressure=4.0)
    settings = SimulationSettings(
        controller=PIController(rtol=1e-6, atol=1e-13),
        save_planes=[length],
        dz_init=0.002,
        dz_max=0.002,
        stats=StatsSpec(names=("energy",)),
    )
    result = prop_free(
        grid,
        space,
        argon,
        [KerrResponse(gamma3("Ar", wavelength=800e-9), thg=False)],
        SpatialPulse(GaussianPulse(wavelength=800e-9, fwhm=30e-15, energy=1.5e-9), 2e-3),
        settings=settings,
    )
    # The fluence is the time-integrated axial flux, measured in the argon at the exit.
    exit_plane = SpatialFlux.resolve(grid, space, argon, z=length)
    fluence = spatial_fluence(result.fields("fft")[-1], exit_plane).reshape(
        space.n_y, space.n_x
    )
    figure, axis = plt.subplots(figsize=(6, 4))
    view = axis.pcolormesh(space.x * 1e3, space.y * 1e3, fluence, shading="auto")
    axis.set(xlabel="x (mm)", ylabel="y (mm)", aspect="equal")
    figure.colorbar(view, ax=axis, label="Fluence (J/m²)")
    figure.tight_layout()
    print(f"Saved energy: {float(np.asarray(result['stats/energy'])[-1].item()):.6g} J")




.. image-sg:: /auto_tutorials/free_space/images/sphx_glr_plot_02_cartesian_001.png
   :alt: plot 02 cartesian
   :srcset: /auto_tutorials/free_space/images/sphx_glr_plot_02_cartesian_001.png
   :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    Saved energy: 1.5e-09 J




.. GENERATED FROM PYTHON SOURCE LINES 63-69

Related reading
---------------
Continue with :doc:`/guide/free-space/cartesian` for the model, options and limits,
and :doc:`/guide/numerics/accuracy` for convergence checks.
For a paced propagation lesson, return to
:doc:`/introduction/lessons/plot_04_crossing_beams`.


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

   **Total running time of the script:** (0 minutes 2.517 seconds)


.. _sphx_glr_download_auto_tutorials_free_space_plot_02_cartesian.py:

.. only:: html

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

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

      :download:`Download Jupyter notebook: plot_02_cartesian.ipynb <plot_02_cartesian.ipynb>`

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

      :download:`Download Python source code: plot_02_cartesian.py <plot_02_cartesian.py>`

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

      :download:`Download zipped: plot_02_cartesian.zip <plot_02_cartesian.zip>`