Editing Polarization (waves) (section)

=== Degree of polarization {{anchor|Degree}} ===
'''Degree of polarization''' ('''DOP''') is a quantity used to describe the portion of an [[electromagnetic wave]] which is polarized. {{abbr|DOP|degree of polarization}} can be calculated from the [[Stokes parameters]]. A perfectly polarized wave has a {{abbr|DOP|degree of polarization}} of 100%, whereas an unpolarized wave has a {{abbr|DOP|degree of polarization}} of 0%.  A wave which is partially polarized, and therefore can be represented by a superposition of a polarized and unpolarized component, will have a {{abbr|DOP|degree of polarization}} somewhere in between 0 and 100%. {{abbr|DOP|degree of polarization}} is calculated as the fraction of the total power that is carried by the polarized component of the wave.

{{abbr|DOP|degree of polarization}} can be used to map the [[Strain (materials science)|strain]] field in materials when considering the {{abbr|DOP|degree of polarization}} of the [[photoluminescence]]. The polarization of the photoluminescence is related to the strain in a material by way of the given material's [[photoelasticity tensor]].

{{abbr|DOP|degree of polarization}} is also visualized using the [[Poincaré sphere (optics)|Poincaré sphere]] representation of a polarized beam.  In this representation, {{abbr|DOP|degree of polarization}} is equal to the length of the [[Vector (geometric)|vector]] measured from the center of the sphere.