Optics (Symbols)
================

Symbols related to optics.

.. py:currentmodule:: symplyphysics.symbols.optics

.. py:data:: relative_refractive_index

    **Relative refractive index** of of an optical medium is a dimensionless number that gives the
    indication of the light bending ability of that medium. It is defined relative to a certain medium.

Symbol:
    :code:`n`

Latex:
    :math:`n`

Dimension:
    :code:`dimensionless`


.. py:data:: radiant_exitance

    **Radiant exitance** or **radiant emittance** is the radiant flux emitted by a surface per unit area.

Symbol:
    :code:`M_e`

Latex:
    :math:`M_\text{e}`

Dimension:
    :code:`power/area`


.. py:data:: radiant_flux

    **Radiant flux** or **radiant power** is the radiant energy emitted, reflected, transmitted, or
    received per unit time.

Symbol:
    :code:`Phi_e`

Latex:
    :math:`\Phi_\text{e}`

Dimension:
    :code:`power`


.. py:data:: focal_length

    The **focal length** of an optical system is a measure of how strongly the system converges or diverges
    light; it is the inverse of the system's optical power. It is the distance between the focal plane and
    the lens's nodal point.

Symbol:
    :code:`f`

Latex:
    :math:`f`

Dimension:
    :code:`length`


.. py:data:: optical_distance

    **Optical distance**, also called **optical path length**, is the length that light needs to travel
    through a vacuum to create the same phase difference as it would have when traveling through a given medium.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Optical_path_length>`__.

Symbol:
    :code:`Lambda`

Latex:
    :math:`\Lambda`

Dimension:
    :code:`length`


.. py:data:: irradiance

    In radiometry, **irradiance** is the radiant flux received by a surface per unit area.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Irradiance>`__.

Symbol:
    :code:`E_e`

Latex:
    :math:`E_\text{e}`

Dimension:
    :code:`power/area`


.. py:data:: transparency_coefficient

    The transparency coefficient is used to describe how much light an imperfect polarizer absorbs,
    zero being a total absorption and one being a perfect polarizer that lets all light pass through.

    ..
        TODO check if this is the correct English name

Symbol:
    :code:`k`

Latex:
    :math:`k`

Dimension:
    :code:`dimensionless`


.. py:data:: reflectance

    The **reflectance** of the surface of a material is its effectiveness in reflecting radiant energy.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Reflectance>`__.

Symbol:
    :code:`R`

Latex:
    :math:`R`

Dimension:
    :code:`dimensionless`


.. py:data:: magnification

    Optical **magnification** is the ratio between the apparent size in an image and its true size.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Magnification#Size_ratio_(optical_magnification)>`__.

Symbol:
    :code:`M`

Latex:
    :math:`M`

Dimension:
    :code:`dimensionless`


.. py:data:: optical_power

    **Optical power**, also callled **dioptric power** or **focusing power**, is the degree to which
    a lens, mirror, or other optical system converges or diverges light.

Symbol:
    :code:`D`

Latex:
    :math:`D`

Dimension:
    :code:`1/length`


.. py:data:: angular_resolution

    **Angular resolution** describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Angular_resolution#>`__.

Symbol:
    :code:`theta`

Latex:
    :math:`\theta`

Dimension:
    :code:`angle`