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

.. only:: html

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

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

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

.. _sphx_glr_examples_interferometer.py:


Interferometer
==============

A double slit interferometer with a point source. Multiprocess propagation is 
used to obtain the interferogram produced by different configurations of the 
optical system.

.. GENERATED FROM PYTHON SOURCE LINES 11-12

Import libraries required for simulation

.. GENERATED FROM PYTHON SOURCE LINES 12-19

.. code-block:: default

    from copy import deepcopy

    import matplotlib.pyplot as plt
    import numpy as np

    import pysrw as srw








.. GENERATED FROM PYTHON SOURCE LINES 20-22

Create the wavefront arriving at the first plane of the optical system with 
parameters similar to :doc:`simple_propagation`

.. GENERATED FROM PYTHON SOURCE LINES 22-39

.. code-block:: default


    ptSrc = srw.emitters.PointSource()

    observer = srw.wavefronts.Observer(centerCoord=[0, 0, .5],
                                       obsXextension=5e-3, 
                                       obsYextension=5e-3,
                                       obsXres=1e-6,
                                       obsYres=1e-6)

    wfr = srw.computePtSrcWfr(ptSrc, observer, wavelength=600)

    w = 500e-6
    d = 2e-3
    f = 50e-3
    s1 = observer.zPos
    s2 = s1 * f / (s1 - f)








.. GENERATED FROM PYTHON SOURCE LINES 40-42

We use a rectangular aperture with an obstacle at the centre to create the 
two interferometer slits

.. GENERATED FROM PYTHON SOURCE LINES 42-68

.. code-block:: default


    optSystem = {
        "slitAp": {
            "type": "rectAp",
            "extension": [w, d + w],
            "centre": [0,0]
        },
        "slitOb": {
            "type": "rectOb",
            "extension": [2 * w, d - w],
            "centre": [0,0]
        },
        "lens": {
            "type": "lens",
            "f": f,
            "centre": [0,0]
        },
        "image": {
            "type": "drift",
            "length": s2,
            "resParam": {"hRangeChange": 1/20, "hResChange": 2.0,
                         "vRangeChange": 1/20, "vResChange": 2.0,
                         "hCentreChange": 0.0, "vCentreChange": 0.0}
        }
    }








.. GENERATED FROM PYTHON SOURCE LINES 69-72

We proceed with a standard propagation to check that the parameters are good.
As expected, the interferogram of the point emitter exhibits a unitary 
visibility and its envelope lies within the single slit diffraction pattern.

.. GENERATED FROM PYTHON SOURCE LINES 72-90

.. code-block:: default


    propData = srw.propagateWfr(wfr, optSystem, saveIntAt=["image"])
    srw.plotI(propData["image"]["intensity"])

    cuts = srw.extractCrossCuts(propData["image"]["intensity"])
    yax = cuts["yax"]
    int_srw = cuts["ydata"]
    int_theo = np.sinc(w * yax / (s2 * wfr.wavelength*1e-9))**2

    fig, ax = plt.subplots()
    ax.plot(yax*1e3, int_srw / np.max(int_srw))
    ax.plot(yax*1e3, int_theo, label="theo", linestyle="--")
    ax.set_xlabel("y position [mm]")
    ax.set_ylabel("Intensity [arb. unit]")
    ax.legend()
    plt.tight_layout()
    plt.show()




.. rst-class:: sphx-glr-horizontal


    *

      .. image-sg:: /examples/images/sphx_glr_interferometer_001.png
         :alt: interferometer
         :srcset: /examples/images/sphx_glr_interferometer_001.png
         :class: sphx-glr-multi-img

    *

      .. image-sg:: /examples/images/sphx_glr_interferometer_002.png
         :alt: interferometer
         :srcset: /examples/images/sphx_glr_interferometer_002.png
         :class: sphx-glr-multi-img





.. GENERATED FROM PYTHON SOURCE LINES 91-93

We can finally create a list of optical systems by changing the slit 
separation and observe the corresponding change in the fringe periodicity.

.. GENERATED FROM PYTHON SOURCE LINES 93-116

.. code-block:: default


    deltas = np.linspace(-.5, .5, 3) * 1e-3

    optSystems = []
    for delta in deltas:
        optSystemNew = deepcopy(optSystem)
        optSystemNew["slitAp"]["extension"][1] += delta
        optSystemNew["slitOb"]["extension"][1] += delta

        optSystems.append(optSystemNew)

    propDatas = srw.propagateWfrMultiProcess(4, wfr, optSystems, saveIntAt=["image"])

    fig, ax = plt.subplots()
    for i, propData in enumerate(propDatas):
        cuts = srw.extractCrossCuts(propData["image"]["intensity"])
        yax = cuts["yax"]
        int_srw = cuts["ydata"]
        ax.plot(yax*1e3, int_srw / np.max(int_srw), label=f"{(d + deltas[i])*1e3}")
    ax.set_xlabel("y position [mm]")
    ax.set_ylabel("Intensity [arb. unit]")
    ax.legend(title="Separation [mm]")
    plt.tight_layout()
    plt.show()


.. image-sg:: /examples/images/sphx_glr_interferometer_003.png
   :alt: interferometer
   :srcset: /examples/images/sphx_glr_interferometer_003.png
   :class: sphx-glr-single-img






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

   **Total running time of the script:** (0 minutes 28.020 seconds)

**Estimated memory usage:**  2288 MB


.. _sphx_glr_download_examples_interferometer.py:

.. only:: html

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




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

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

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

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


.. only:: html

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

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