polarization

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polarization

, polarisation
Physics the process or phenomenon in which the waves of light or other electromagnetic radiation are restricted to certain directions of vibration, usually specified in terms of the electric field vector

polarization

(poh-lă-ri-zay -shŏn) The degree to which the orientation of the electric or magnetic vector in electromagnetic radiation is predictable over time. In a partially polarized wave, the vector thus shows a less random orientation in the plane perpendicular to the direction of wave motion than occurs in an unpolarized (normal) wave. Waves in which the electric vectors are entirely vertical or horizontal with respect to the direction of motion are described as vertically or horizontally plane (or linearly) polarized. In general, both polarizations are present with a relative phase difference and the wave is then elliptically polarized in the right-handed or left-handed sense accordingly as the resultant vector rotates clockwise or counterclockwise when viewed along the direction of motion of the wave; in the case where the resultant vector rotates and its magnitude remains constant, the wave is circularly polarized.

Polarization is a measure of the way in which light or other electromagnetic radiation from a celestial body is affected by factors such as scattering due to cosmic dust or strong stellar or interstellar magnetic fields, or reflection from a surface. Radio emissions from celestial sources are usually partially polarized, i.e. the waves can be considered to be composed of a completely unpolarized component plus a small polarized component. Synchrotron emission, however, may be strongly polarized. The general situation is described by the four Stokes parameters (I, Q, U, and V ), which are defined in such a manner that specifying their four values uniquely describes the state of polarization: I is a measure of the total power in the wave, Q and U define the degree of linear polarization, and V that of circular polarization. All four have dimensions of flux density. See also Faraday rotation; interstellar polarization.

polarization

[‚pō·lə·rə′zā·shən]
(electricity)
The process of producing a relative displacement of positive and negative bound charges in a body by applying an electric field.
A vector quantity equal to the electric dipole moment per unit volume of a material. Also known as dielectric polarization; electric polarization.
A chemical change occurring in dry cells during use, increasing the internal resistance of the cell and shortening its useful life.
(physics)
Phenomenon exhibited by certain electromagnetic waves and other transverse waves in which the direction of the electric field or the displacement direction of the vibrations is constant or varies in some definite way. Also known as wave polarization.
The direction of the electric field or the displacement vector of a wave exhibiting polarization (first definition).
The process of bringing about polarization (first definition) in a transverse wave.
Property of a collection of particles with spin, in which the majority have spin components pointing in one direction, rather than at random.
References in periodicals archive ?
In case of urban Pakistan, the result of income inequality and polarisation shows that from 1990-91 to 1992-93 it increases followed by a decreasing trend from 1992-93 to 1996-97 except the Foster and Wolfson measure.
As from 2001-02 to 2005-06 all the inequality measures decreases, while the Foster and Wolfson measure of Polarisation increases.
Three features are revealed by the results of inequality and Polarisation measures.
Since the rural population accounts for more than 65 per cent of total population [Pakistan (2007)] it is worthwhile, to compare the measures of inequality and polarisation for rural Pakistan.
In this section the study compared the trends of income inequality and polarisation of all the provinces over the study period.
First, the overall trend for both inequality and polarisation measures increases but at substantially different rates till 1996-97 except the Foster and Wolfson measure.
Moreover, this decline in polarisation could be due to effective policies of the first phase of the Social Action Programmes (SAP-I), which strengthened the middle class.
The magnitude of polarisation is found to be larger in urban areas than in rural ones.
The estimates of the Bossert-Schworm measure of polarisation with respect to aggregate household incomes show relatively higher polarisation.
This section will cover the polarisation trends in all four provinces.
The estimates of polarisation with respect to adult-equivalent incomes shows that during 1992-93 till 1996-97 polarisation has declined in all segments of Punjab.
The estimates of per adult-equivalent income polarisation in Sindh have also the similar trends as for Pakistan.