.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "auto_tutorials/waveguides/plot_04_vector_mode_providers.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_waveguides_plot_04_vector_mode_providers.py>`
        to download the full example code.

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

.. _sphx_glr_auto_tutorials_waveguides_plot_04_vector_mode_providers.py:


Inspect step-index and graded-index electric fields
===================================================

Compare a bound hybrid strand mode with a radial TE graded-index mode. The
providers return full E/H fields normalised by Poynting flux. This example
inspects mode construction; to propagate on such a guide, pass it to
``prop_waveguide(provider=...)`` (the general modal route: see
:ref:`sphx_glr_auto_tutorials_waveguides_plot_05_general_modal.py`,
:ref:`sphx_glr_auto_tutorials_waveguides_plot_06_graded_index.py` and the worked
examples).

.. GENERATED FROM PYTHON SOURCE LINES 17-78

.. code-block:: Python


    import matplotlib.pyplot as plt
    import numpy as np

    from solprop.constants import C
    from solprop.modes import (
        GradedIndexProvider,
        IndexMaterial,
        ModalGuide,
        PowerLawPermittivity,
        StepIndexMode,
    )

    omega = 2 * np.pi * C / 835e-9
    mode = StepIndexMode(250e-9, core=1.45, cladding=1.0, profile_wavelength=835e-9)
    step = ModalGuide.from_step_index(
        [mode], core=IndexMaterial(1.45), cladding=IndexMaterial(1.0)
    ).field_provider
    step_nodes = step.node_rule(omega, n_r=32, n_theta=9)
    step_fields = step.solve(omega, 0.0, nodes=step_nodes)
    grin = GradedIndexProvider(
        permittivity=PowerLawPermittivity(IndexMaterial(1.45), 0.005),
        exterior=IndexMaterial(1.45 * np.sqrt(0.99)),
        radius=25e-6,
        family="TE",
        count=1,
        elements=32,
        extent=2.0,
    )
    grin_nodes = grin.node_rule(2 * np.pi * C / 1.03e-6, n_theta=9)
    grin_fields = grin.solve(2 * np.pi * C / 1.03e-6, 0.0, nodes=grin_nodes)

    fig, axes = plt.subplots(1, 2, figsize=(8, 3), constrained_layout=True)
    for ax, nodes, sample, radius, title in (
        (axes[0], step_nodes, step_fields, 250e-9, "Step-index HE11"),
        (axes[1], grin_nodes, grin_fields, 25e-6, "Parabolic GRIN TE01"),
    ):
        # The polar rule lays its nodes out angle-major, so the layout is
        # (n_theta, n_radial). Take n_theta from the rule that built it rather than
        # writing the number in twice.
        n_theta = nodes.identity["n_theta"]
        radial = np.hypot(nodes.xy[:, 0], nodes.xy[:, 1]).reshape(n_theta, -1)[0] / radius
        electric = (
            np.sum(abs(sample.electric[:, :, 0]) ** 2, axis=1)
            .reshape(n_theta, -1)
            .mean(axis=0)
        )
        longitudinal = abs(sample.electric[:, 2, 0]) ** 2
        longitudinal = longitudinal.reshape(n_theta, -1).mean(axis=0)
        ax.plot(radial, electric / electric.max(), label="Total electric norm")
        ax.plot(radial, longitudinal / electric.max(), label="Longitudinal part")
        ax.axvline(1, color="grey", linewidth=0.8)
        ax.set(
            xlim=(0, 2),
            xlabel="Radius / core radius",
            ylabel="Relative electric norm",
            title=title,
        )
    axes[0].legend(fontsize="small")
    plt.show()




.. image-sg:: /auto_tutorials/waveguides/images/sphx_glr_plot_04_vector_mode_providers_001.png
   :alt: Step-index HE11, Parabolic GRIN TE01
   :srcset: /auto_tutorials/waveguides/images/sphx_glr_plot_04_vector_mode_providers_001.png
   :class: sphx-glr-single-img





.. GENERATED FROM PYTHON SOURCE LINES 79-86

Related reading
---------------
Continue with :doc:`/guide/waveguides/vector-fields` 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_02_soliton`.


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

   **Total running time of the script:** (0 minutes 0.205 seconds)


.. _sphx_glr_download_auto_tutorials_waveguides_plot_04_vector_mode_providers.py:

.. only:: html

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

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

      :download:`Download Jupyter notebook: plot_04_vector_mode_providers.ipynb <plot_04_vector_mode_providers.ipynb>`

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

      :download:`Download Python source code: plot_04_vector_mode_providers.py <plot_04_vector_mode_providers.py>`

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      :download:`Download zipped: plot_04_vector_mode_providers.zip <plot_04_vector_mode_providers.zip>`