What is polarization?
Polarization (waves)
Polarization (also polarisation) is a property applying to transverse waves that specifies the geometrical orientation of the oscillations. In a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. A simple example of a polarized transverse wave is vibrations traveling along a taut string "(see image)"; for example, in a musical instrument like a guitar string. Depending on how the string is plucked, the vibrations can be in a vertical direction, horizontal direction, or at any angle perpendicular to the string. In contrast, in longitudinal waves, such as sound waves in a liquid or gas, the displacement of the particles in the oscillation is always in the direction of propagation, so these waves do not exhibit polarization. Transverse waves that exhibit polarization include electromagnetic waves such as light and radio waves, gravitational waves, and transverse sound waves (shear waves) in solids. In some types of transverse waves, the wave displacement is limited to a single direction, so these also do not exhibit polarization; for example, in surface waves in liquids (gravity waves), the wave displacement of the particles is always in a vertical plane.
Polarization density
In classical electromagnetism, polarization density (or electric polarization, or simply polarization) is the vector field that expresses the density of permanent or induced electric dipole moments in a dielectric material. When a dielectric is placed in an external electric field, its molecules gain electric dipole moment and the dielectric is said to be polarized. The electric dipole moment induced per unit volume of the dielectric material is called the electric polarization of the dielectric.
Polarization of an algebraic form
In mathematics, in particular in algebra, polarization is a technique for expressing a homogeneous polynomial in a simpler fashion by adjoining more variables. Specifically, given a homogeneous polynomial, polarization produces a multilinear form from which the original polynomial can be recovered by evaluating along a certain diagonal.
Polarization (waves)
One can visualize the case of linear birefringence (with two orthogonal linear propagation modes) with an incoming wave linearly polarized at a 45° angle to those modes. As a differential phase starts to accrue, the polarization becomes elliptical, eventually changing to purely circular polarization (90° phase difference), then to elliptical and eventually linear polarization (180° phase) perpendicular to the original polarization, then through circular again (270° phase), then elliptical with the original azimuth angle, and finally back to the original linearly polarized state (360° phase) where the cycle begins anew. In general the situation is more complicated and can be characterized as a rotation in the Poincaré sphere about the axis defined by the propagation modes. Examples for linear (blue), circular (red), and elliptical (yellow) birefringence are shown in the figure on the left. The total intensity and degree of polarization are unaffected. If the path length in the birefringent medium is sufficient, the two polarization components of a collimated beam (or ray) can exit the material with a positional offset, even though their final propagation directions will be the same (assuming the entrance face and exit face are parallel). This is commonly viewed using calcite crystals, which present the viewer with two slightly offset images, in opposite polarizations, of an object behind the crystal. It was this effect that provided the first discovery of polarization, by Erasmus Bartholinus in 1669.
Polarization (politics)
Morris P. Fiorina (2006, 2008) posits the hypothesis that polarization is a phenomenon which does not hold for the public, and instead is formulated by commentators to draw further division in government. Other studies indicate that cultural differences focusing on ideological movements and geographical polarization within the United States constituency is correlated with rises in overall political polarization between 1972 and 2004.
Partisan sorting
Partisan sorting or geographic sorting is an effect in politics in which voters with specific viewpoints migrate to specific areas, becoming much more concentrated in them than in the wider electorate. This effect may create or contribute to an effect of polarization, in which separate areas become dominated by political movements much more extreme than might be expected given the "average" political views of voters.
Polarization density
Polarization density also describes how a material responds to an applied electric field as well as the way the material changes the electric field, and can be used to calculate the forces that result from those interactions. It can be compared to magnetization, which is the measure of the corresponding response of a material to a magnetic field in magnetism. The SI unit of measure is coulombs per square meter, and polarization density is represented by a vector P.
Polarography
Polarography is a voltammetric measurement whose response is determined by combined diffusion/convection mass transport. The simple principle of polarography is the study of solutions or of electrode processes by means of electrolysis with two electrodes, one polarizable and one unpolarizable, the former formed by mercury regularly dropping from a capillary tube. 
Polarography is a specific type of measurement that falls into the general category of linear-sweep voltammetry where the electrode potential is altered in a linear fashion from the initial potential to the final potential. As a linear sweep method controlled by convection/diffusion mass transport, the current vs. potential response of a polarographic experiment has the typical sigmoidal shape. What makes polarography different from other linear sweep voltammetry measurements is that polarography makes use of the dropping mercury electrode (DME) or the static mercury drop electrode.
Degree of polarization
Degree of polarization (DOP) is a quantity used to describe the portion of an electromagnetic wave which is polarized. A perfectly polarized wave has a DOP of 100%, whereas an unpolarized wave has a DOP 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 DOP somewhere in between 0 and 100%. DOP is calculated as the fraction of the total power that is carried by the polarised component of the wave.
Polarimeter
A polarimeter is a scientific instrument used to measure the angle of rotation caused by passing polarized light through an optically active substance.
Some chemical substances are optically active, and polarized (uni-directional) light will rotate either to the left (counter-clockwise) or right (clockwise) when passed through these substances. The amount by which the light is rotated is known as the angle of rotation. The angle of rotation is basically known as observed angle.
Polarization controller
Polarization controllers can be operated without feedback, typically by manual adjustment or by electrical signals from a generator, or with automatic feedback. The latter allows for fast polarization tracking.
A polarization controller can have the task of transforming a fixed, known polarization into an arbitrary one. Since polarization states are defined by two degrees of freedom, for example azimuth angle and ellipticity angle of the polarization state, such a polarization controller needs two degrees of freedom. The same holds for the task of transforming an arbitrary polarization into a fixed, known one.
Plate reader
Fluorescence polarization measurement is also very close to FI detection. The difference is that the optical system includes polarizing filters on the light path: the samples in the microplate are excited using polarized light (instead of non-polarized light in FI and TRF modes). Depending on the mobility of the fluorescent molecules found in the wells, the light emitted will either be polarized or not. For example, large molecules (e.g. proteins) in solution, which rotate relatively slowly because of their size, will emit polarized light when excited with polarized light. On the other hand, the fast rotation of smaller molecules will result in a depolarization of the signal. The emission system of the plate reader uses polarizing filters to analyze the polarity of the emitted light. A low level of polarization indicates that small fluorescent molecules move freely in the sample. A high level of polarization indicates that fluorescent is attached to a larger molecular complex. As a result, one of the basic applications of FP detection is molecular binding assays, since they allow to detect if a small fluorescent molecule binds (or not) to a larger, non-fluorescent molecule: binding results in a slower rotation speed of the fluorescent molecule, and in an increase in the polarization of the signal.
Polarization (politics)
Some scholars argue that polarization lowers public interest in politics, party identification and voter turnout. It encourages confrontational dynamics between parties that can lower overall public trust and approval in government., and causes the public to perceive the general political debate as less civil, which can alienate voters. More polarized candidates, especially when voters aren't aware of the increase, also tend to be less representative of the public's wishes.
Polarization in astronomy
The polarization of starlight was first observed by the astronomers William Hiltner and John S. Hall in 1949. Subsequently, Jesse Greenstein and Leverett Davis, Jr. developed theories allowing the use of polarization data to trace interstellar magnetic fields. 
Though the integrated thermal radiation of stars is not usually appreciably polarized at source, scattering by interstellar dust can impose polarization on starlight over long distances. Net polarization at the source can occur if the photosphere itself is asymmetric, due to limb polarization. Plane polarization of starlight generated at the star itself is observed for Ap stars (peculiar A type stars).
Polarized 3D system
To present a stereoscopic motion picture, two images are projected superimposed onto the same screen through orthogonal polarizing filters (Usually at 45 and 135 degrees). The viewer wears linearly polarized eyeglasses which also contain a pair of orthogonal polarizing filters oriented the same as the projector. As each filter only passes light which is similarly polarised and blocks the orthogonally polarized light, each eye only sees one of the projected images, and the 3D effect is achieved. Linearly polarised glasses require the viewer to keep his or her head level, as tilting of the viewing filters will cause the images of the left and right channels to bleed over to the opposite channel. This can make prolonged viewing uncomfortable as head movement is limited to maintain the 3D effect.
To present a stereoscopic motion picture, two images are projected superimposed onto the same screen through circular polarizing filters of opposite handedness. The viewer wears eyeglasses which contain a pair of analyzing filters (circular polarizers mounted in reverse) of opposite handedness. Light that is left-circularly polarized is blocked by the right-handed analyzer, while right-circularly polarized light is blocked by the left-handed analyzer. The result is similar to that of stereoscopic viewing using linearly polarized glasses, except the viewer can tilt his or her head and still maintain left/right separation (although stereoscopic image fusion will be lost due to the mismatch between the eye plane and the original camera plane).
As shown in the figure, the analyzing filters are constructed of a quarter-wave plate (QWP) and a linearly polarized filter (LPF). The QWP always transforms circularly polarized light into linearly polarized light. However, the angle of polarization of the linearly polarized light produced by a QWP depends on the handedness of the circularly polarized light entering the QWP. In the illustration, the left-handed circularly polarized light entering the analyzing filter is transformed by the QWP into linearly polarized light which has its direction of polarization along the transmission axis of the LPF. Therefore, in this case the light passes through the LPF. In contrast, right-handed circularly polarized light would have been transformed into linearly polarized light that had its direction of polarization along the absorbing axis of the LPF, which is at right angles to the transmission axis, and it would have therefore been blocked.
Linear polarization
In electrodynamics, linear polarization or plane polarization of electromagnetic radiation is a confinement of the electric field vector or magnetic field vector to a given plane along the direction of propagation. See "polarization" and "plane of polarization" for more information.
Abelian variety
A polarisation of an abelian variety is an "isogeny" from an abelian variety to its dual that is symmetric with respect to "double-duality" for abelian varieties and for which the pullback of the Poincaré bundle along the associated graph morphism is ample (so it is analogous to a positive-definite quadratic form). Polarised abelian varieties have finite automorphism groups. A principal polarisation is a polarisation that is an isomorphism. Jacobians of curves are naturally equipped with a principal polarisation as soon as one picks an arbitrary rational base point on the curve, and the curve can be reconstructed from its polarised Jacobian when the genus is > 1. Not all principally polarised abelian varieties are Jacobians of curves; see the Schottky problem. A polarisation induces a Rosati involution on the endomorphism ring formula_4 of "A".
Optics
Polarization is a general property of waves that describes the orientation of their oscillations. For transverse waves such as many electromagnetic waves, it describes the orientation of the oscillations in the plane perpendicular to the wave's direction of travel. The oscillations may be oriented in a single direction (linear polarization), or the oscillation direction may rotate as the wave travels (circular or elliptical polarization). Circularly polarised waves can rotate rightward or leftward in the direction of travel, and which of those two rotations is present in a wave is called the wave's chirality.
Polarized light pollution
In nature, water and water vapor polarize the sunlight (which itself is slightly polarized). By receiving the direction of polarized photons, some species can correct their course during migration. Artificial polarization of natural or artificial light can disrupt the behavior of these species and the ecosystems in which these species play an important role. Pollination is one example of this.
Polarization (waves)
When plotted, that point will lie on the surface of the unity-radius Poincaré sphere and indicate the state of polarization of the polarized component.
Polarization of an algebraic form
Let u, u, ..., u be a collection of indeterminates with u = ("u", "u", ..., "u"), so that there are "dn" variables altogether. The polar form of "f" is a polynomial
which is linear separately in each u (i.e., "F" is multilinear), symmetric in the u, and such that
Polarization (waves)
In addition to birefringence and dichroism in extended media, polarization effects describable using Jones matrices can also occur at (reflective) interface between two materials of different refractive index. These effects are treated by the Fresnel equations. Part of the wave is transmitted and part is reflected; for a given material those proportions (and also the phase of reflection) are dependent on the angle of incidence and are different for the "s" and "p" polarizations. Therefore, the polarization state of reflected light (even if initially unpolarized) is generally changed.
Any light striking a surface at a special angle of incidence known as Brewster's angle, where the reflection coefficient for "p" polarization is zero, will be reflected with only the "s"-polarization remaining. This principle is employed in the so-called "pile of plates polarizer" (see figure) in which part of the "s" polarization is removed by reflection at each Brewster angle surface, leaving only the "p" polarization after transmission through many such surfaces. The generally smaller reflection coefficient of the "p" polarization is also the basis of polarized sunglasses; by blocking the "s" (horizontal) polarization, most of the glare due to reflection from a wet street, for instance, is removed.
Polarization (politics)
There have long been numerous scholarly debates that argue over the concept of political polarization, both in whether it is valid, and how it can accurately be measured. There are four primary arguments against the validity of political polarization: 1) Limitations of the Two-Party System, 2) Issue Partisanship, 3) Cultural Differences, and 4) Westernized Focuses.
Polarized 3D system
Particularly with the linear polarization schemes popular since the 1950s, the use of linear polarization meant that a level head was required for any sort of comfortable viewing; any effort to tilt the head sideways would result in the polarization failing, ghosting, and both eyes seeing both images. Circular polarization has alleviated this problem, allowing viewers to tilt their heads slightly (although any offset between the eye plane and the original camera plane will still interfere with the perception of depth).
Polarization (waves)
Light or other electromagnetic radiation from many sources, such as the sun, flames, and incandescent lamps, consists of short wave trains with an equal mixture of polarizations; this is called "unpolarized light". Polarized light can be produced by passing unpolarized light through a polarizer, which allows waves of only one polarization to pass through. The most common optical materials (such as glass) are isotropic and do not affect the polarization of light passing through them; however, some materials—those that exhibit birefringence, dichroism, or optical activity—can change the polarization of light. Some of these are used to make polarizing filters. Light is also partially polarized when it reflects from a surface.
Circular polarization
The nature of circular polarization and its relationship to other polarizations is often understood by thinking of the electric field as being divided into two components which are at right angles to each other. Refer to the second illustration on the right. The vertical component and its corresponding plane are illustrated in blue while the horizontal component and its corresponding plane are illustrated in green. Notice that the rightward (relative to the direction of travel) horizontal component leads the vertical component by one quarter of a wavelength. It is this quadrature phase relationship which creates the helix and causes the points of maximum magnitude of the vertical component to correspond with the points of zero magnitude of the horizontal component, and vice versa. The result of this alignment is that there are select vectors, corresponding to the helix, which exactly match the maxima of the vertical and horizontal components. (To minimize visual clutter these are the only helix vectors displayed.)
Optics
Most sources of electromagnetic radiation contain a large number of atoms or molecules that emit light. The orientation of the electric fields produced by these emitters may not be correlated, in which case the light is said to be "unpolarised". If there is partial correlation between the emitters, the light is "partially polarised". If the polarization is consistent across the spectrum of the source, partially polarised light can be described as a superposition of a completely unpolarised component, and a completely polarised one. One may then describe the light in terms of the degree of polarization, and the parameters of the polarization ellipse.
Raman spectroscopy
Polarization–dependent Raman spectroscopy uses (plane) polarized laser excitation from a polarizer. The Raman scattered light collected is passed through a second polarizer (called the analyzer) before entering the detector. The analyzer is oriented either parallel or perpendicular to the polarization of the laser. Spectra acquired with the analyzer set at both perpendicular and parallel to the excitation plane can be used to calculate the depolarization ratio. Typically a polarization scrambler is placed between the analyzer and detector also. It is convenient in polarized Raman spectroscopy to describe the propagation and polarization directions using Porto's notation, described by and named after Brazilian physicist Sergio Pereira da Silva Porto.
Concentration polarization
In membrane science and technology, concentration polarization refers to the emergence of concentration gradients at a membrane/solution interface resulted from selective transfer of some species through the membrane under the effect of transmembrane driving forces. 
Generally, the cause of concentration polarization is the ability of a membrane to transport some species more readily than the other(s) (which is the membrane permselectivity): the retained species are concentrated at the upstream membrane surface while the concentration of transported species decreases. Thus, concentration polarization phenomenon is inherent to all types of membrane separation processes. In the cases of gas separations, pervaporation, membrane distillation, reverse osmosis, nanofiltration, ultrafiltration, and microfiltration separations, the concentration profile has a higher level of solute nearest to the upstream membrane surface compared with the more or less well mixed bulk fluid far from the membrane surface. In the case of dialysis and electrodialysis, the concentrations of selectively transported dissolved species are reduced at the upstream membrane surface compared to the bulk solution. 
The emergence of concentration gradients is illustrated in Figs. 1a and 1b. Fig. 1a shows the concentration profile near and within a membrane when an external driving force is just applied to an initially equilibrium system. Concentration gradients have not yet formed. If the membrane is selectively permeable to species 1, its flux (formula_1) within the membrane is higher than that in the solution (formula_2). Higher flux in the membrane causes a decrease in the concentration at the upstream membrane surface (formula_3) and an increase at the downstream surface (formula_4), Fig. 1b. Thus, the upstream solution becomes depleted and the downstream solution becomes enriched in regard to species 1. The concentration gradients cause additional diffusion fluxes, which contribute to an increase of the total flux in the solutions and to a decrease of the flux in the membrane. As a result, the system reaches a steady state where formula_5. The greater the external force applied, the lower formula_6. In electrodialysis, when formula_3 becomes much lower than the bulk concentration, the resistance of the depleted solution becomes quite elevated. The current density related to this state is known as the limiting current density.
Polarization (waves)
Especially due to the presence of the ground, there are some differences in propagation (and also in reflections responsible for TV ghosting) between horizontal and vertical polarizations. AM and FM broadcast radio usually use vertical polarization, while television uses horizontal polarization. At low frequencies especially, horizontal polarization is avoided. That is because the phase of a horizontally polarized wave is reversed upon reflection by the ground. A distant station in the horizontal direction will receive both the direct and reflected wave, which thus tend to cancel each other. This problem is avoided with vertical polarization. Polarization is also important in the transmission of radar pulses and reception of radar reflections by the same or a different antenna. For instance, back scattering of radar pulses by rain drops can be avoided by using circular polarization. Just as specular reflection of circularly polarized light reverses the handedness of the polarization, as discussed above, the same principle applies to scattering by objects much smaller than a wavelength such as rain drops. On the other hand, reflection of that wave by an irregular metal object (such as an airplane) will typically introduce a change in polarization and (partial) reception of the return wave by the same antenna.
Polarimeter
Polarization by reflection was discovered in 1808 by Étienne-Louis Malus (1775–1812). (See also Optical rotation#History). A nicol prism or a polaroid filter can be used to polarize the light.
Polarization density
Even though the polarization is "in principle" non-unique, in practice it is often (not always) defined by convention in a specific, unique way. For example, in a perfectly centrosymmetric crystal, P is usually defined by convention to be exactly zero. As another example, in a ferroelectric crystal, there is typically a centrosymmetric configuration above the Curie temperature, and P is defined there by convention to be zero. As the crystal is cooled below the Curie temperature, it shifts gradually into a more and more non-centrosymmetric configuration. Since gradual changes in P are uniquely defined, this convention gives a unique value of P for the ferroelectric crystal, even below its Curie temperature.
Centre for Genomic Regulation
Cell polarity is a prerequisite for several fundamental operations in animal cells, such as asymmetric cell division and morphogenesis. For both of these, polarization is determined by the same set of proteins, known as PAR proteins. It is not known how these proteins set polarity. The investigators have proposed a dual approach, combining in vitro and cell extract techniques. The goal is to gain knowledge about the micrometer scale behavior of the polarizing system, as well as the attributes of its components.
Polarimetry
Polarimetry is the measurement and interpretation of the polarization of transverse waves, most notably electromagnetic waves, such as radio or light waves. Typically polarimetry is done on electromagnetic waves that have traveled through or have been reflected, refracted or diffracted by some material in order to characterize that object.
Polarization (waves)
Here formula_19 and formula_20 denote the amplitude of the wave in the two components of the electric field vector, while formula_21 and formula_22 represent the phases. The product of a Jones vector with a complex number of unit modulus gives a different Jones vector representing the same ellipse, and thus the same state of polarization. The physical electric field, as the real part of the Jones vector, would be altered but the polarization state itself is independent of absolute phase. The basis vectors used to represent the Jones vector need not represent linear polarization states (i.e. be real). In general any two orthogonal states can be used, where an orthogonal vector pair is formally defined as one having a zero inner product. A common choice is left and right circular polarizations, for example to model the different propagation of waves in two such components in circularly birefringent media (see below) or signal paths of coherent detectors sensitive to circular polarization.
Polarization
Polarization or polarisation may refer to:
Polarizing filter (photography)
A polarizing filter or polarising filter (see spelling differences) is often placed in front of the camera lens in photography in order to darken skies, manage reflections, or suppress glare from the surface of lakes or the sea. Since reflections (and sky-light) tend to be at least partially linearly-polarized, a linear polarizer can be used to change the balance of the light in the photograph. The rotational orientation of the filter is adjusted for the preferred artistic effect. For modern cameras, a circular polarizer (product labeling abbreviation: CPL) is typically used; this comprises firstly a linear polarizer which performs the artistic function just described, followed by a quarter-wave plate which further transforms the now-linearly polarized light into circularly-polarised light before entering the camera. This additional step avoids problems with auto-focus and light-metering sensors within some cameras, which otherwise may not function reliably with a simple linear polariser.
Polarization (waves)
Another coordinate system frequently used relates to the "plane of incidence". This is the plane made by the incoming propagation direction and the vector perpendicular to the plane of an interface, in other words, the plane in which the ray travels before and after reflection or refraction. The component of the electric field parallel to this plane is termed "p-like" (parallel) and the component perpendicular to this plane is termed "s-like" (from "senkrecht", German for perpendicular). Polarized light with its electric field along the plane of incidence is thus denoted "p-polarized", while light whose electric field is normal to the plane of incidence is called "s-polarized". "P" polarization is commonly referred to as "transverse-magnetic" (TM), and has also been termed "pi-polarized" or "tangential plane polarized". "S" polarization is also called "transverse-electric" (TE), as well as "sigma-polarized" or "sagittal plane polarized".
Polarization (waves)
The coherency matrix is not easy to visualize, and it is therefore common to describe incoherent or partially polarized radiation in terms of its total intensity ("I"), (fractional) degree of polarization ("p"), and the shape parameters of the polarization ellipse. An alternative and mathematically convenient description is given by the Stokes parameters, introduced by George Gabriel Stokes in 1852. The relationship of the Stokes parameters to intensity and polarization ellipse parameters is shown in the equations and figure below.
Polarizer
In trying to appreciate how the quarter-wave plate transforms the linearly polarized light, it is important to realize that the two components discussed are not entities in and of themselves but are merely mental constructs one uses to help appreciate what is happening. In the case of linearly and circularly polarized light, at each point in space, there is always a single electric field with a distinct vector direction, the quarter-wave plate merely has the effect of transforming this single electric field.
Circular polarizers can also be used to selectively absorb or pass right-handed or left-handed circularly polarized light. It is this feature which is utilized by the 3D glasses in stereoscopic cinemas such as RealD Cinema. A given polarizer which creates one of the two polarizations of light will pass that same polarization of light when that light is sent through it in the other direction. In contrast it will block light of the opposite polarization.
Polarization (economics)
One way of quantifying the polarization of the economy is to compare the fraction of those with incomes that are close to the middle—for example, a range that goes from 50 percent greater than the median to 50 percent less than the median—has fallen since 1970 from just over 50 percent to just over 42 percent. Similarly, the U.S. and the E.U. have shown almost identical trends in the share of employment rise by the high and low skill jobs, and a loss by the middle skill jobs, between 1993 and 2006. Polarization became an issue during the 2012 United States presidential election when Joe Biden asserted that the previous policies had "eviscerated" and "buried" the middle class. This picked up on Stiglitz' statement: "But in recent years, America’s middle class has become eviscerated..."
NOMINATE (scaling method)
Poole and Rosenthal (beginning with their 1984 article "The Polarization of American Politics") have also used NOMINATE data to show that, since the 1970s, party delegations in Congress have become ideologically homogeneous and distant from one another (a phenomenon known as "polarization"). Using DW-NOMINATE scores (which permit direct comparisons between members of different Congresses across time), political scientists have demonstrated the expansion of ideological divides in Congress, which has spurred intense partisanship between Republicans and Democrats in recent decades. Contemporary political polarization has had important political consequences on American public policy, as Poole and Rosenthal (with fellow political scientist Nolan McCarty) show in their book "Polarized America: The Dance of Ideology and Unequal Riches".
Stokes parameters
One way to describe polarization is by giving the semi-major and semi-minor axes of the polarization ellipse, its orientation, and the sense of rotation (See the above figure). The Stokes parameters formula_6, formula_24, formula_25, and formula_13, provide an alternative description of the polarization state which is experimentally convenient because each parameter corresponds to a sum or difference of measurable intensities. The next figure shows examples of the Stokes parameters in degenerate states.
Photon polarization
and the energy density is
Photon polarization
where
Polarizer
There is a relatively straightforward way to appreciate why a polarizer which creates a given handedness of circularly polarized light also passes that same handedness of polarized light. First, given the dual usefulness of this image, begin by imagining the circularly polarized light displayed at the top as still leaving the quarter-wave plate and traveling toward the left. Observe that had the horizontal component of the linearly polarized light been retarded by a quarter of wavelength twice, which would amount to a full half wavelength, the result would have been linearly polarized light that was at a right angle to the light that entered. If such orthogonally polarized light were rotated on the horizontal plane and directed back through the linear polarizer section of the circular polarizer it would clearly pass through given its orientation. Now imagine the circularly polarized light which has already passed through the quarter-wave plate once, turned around and directed back toward the circular polarizer again. Let the circularly polarized light illustrated at the top now represent that light. Such light is going to travel through the quarter-wave plate a second time before reaching the linear polarizer and in the process, its horizontal component is going to be retarded a second time by one quarter of a wavelength. Whether that horizontal component is retarded by one quarter of a wavelength in two distinct steps or retarded a full half wavelength all at once, the orientation of the resulting linearly polarized light will be such that it passes through the linear polarizer.
Polarization (waves)
Regardless of whether polarization state is represented using geometric parameters or Jones vectors, implicit in the parameterization is the orientation of the coordinate frame. This permits a degree of freedom, namely rotation about the propagation direction. When considering light that is propagating parallel to the surface of the Earth, the terms "horizontal" and "vertical" polarization are often used, with the former being associated with the first component of the Jones vector, or zero azimuth angle. On the other hand, in astronomy the equatorial coordinate system is generally used instead, with the zero azimuth (or position angle, as it is more commonly called in astronomy to avoid confusion with the horizontal coordinate system) corresponding to due north.
Optical rotation
The familiar rotation of the axis of "linear" polarization relies on the understanding that a linearly polarized wave can as well be described as the superposition (addition) of a left and right circularly polarized wave in equal proportion. The phase difference between these two waves is dependent on the orientation of the linear polarization which we'll call formula_2, and their electric fields have a relative phase difference of formula_3 which then add to produce linear polarization:
Hyperpolarization (physics)
Hyperpolarization is the nuclear spin polarization of a material far beyond thermal equilibrium conditions. It can be applied to gases such as Xe and He, and small molecules where the polarization levels can be enhanced by a factor of 10-10 above thermal equilibrium levels. Hyperpolarized noble gases are typically used in magnetic resonance imaging (MRI) of the lungs.
Hyperpolarized small molecules are typically used for "in vivo" metabolic imaging. For example, a hyperpolarized metabolite can be injected into animals or patients and the metabolic conversion can be tracked in real-time.
Polarization controller
A polarization controller is an optical device which allows one to modify the polarization state of light.
Intercultural philosophy
Depolarization rule (rule against cultural dualism) – Polarisation is an elementary means of reducing complexity and classifying things. Its primary function is not to render things as they in fact are, but rather to represent them in a manner in which they are useful. Polarisations with their simplification, exaggeration, absolutism, and exclusivity are best prevented by comparing several cultures with each other, instead of restricting the comparison to two, and by paying attention to the circumstances under which such a polar relationship between two cultures can be maintained and under what conditions it can also be detected within the cultures that are contrasted with each other.
Polarization scrambling
Polarization scrambling is the process of rapidly varying the polarization of light within a system using a polarization controller so that the average polarization over time is effectively randomized. Polarization scrambling can be used in scientific experiments to cancel out errors caused by polarization effects. Polarization scrambling is also used on long-distance fibre optic transmission systems with optical amplifiers, in order to avoid polarization hole-burning. Polarization scrambling, also for the variation of polarization mode dispersion, is a mandatory test procedure for fiber optic data transmission systems based on polarization-division multiplexing.
Polarizer
First note that a quarter-wave plate always transforms circularly polarized light into linearly polarized light. It is only the resulting angle of polarization of the linearly polarized light that is determined by the orientation of the fast and slow axes of the quarter-wave plate and the handedness of the circularly polarized light. In the illustration, the left-handed circularly polarized light entering the polarizer is transformed into linearly polarized light which has its direction of polarization along the transmission axis of the linear polarizer and it therefore passes. In contrast right-handed circularly polarized light would have been transformed into linearly polarized light that had its direction of polarization along the absorbing axis of the linear polarizer, which is at right angles to the transmission axis, and it would have therefore been blocked.
To understand this process, refer to the illustration on the right. It is absolutely identical to the earlier illustration even though the circularly polarized light at the top is now considered to be approaching the polarizer from the left. One can observe from the illustration that the leftward horizontal (as observed looking along the direction of travel) component is leading the vertical component and that when the horizontal component is retarded by one quarter of a wavelength it will be transformed into the linearly polarized light illustrated at the bottom and it will pass through the linear polarizer.
Polarizing filter (photography)
Some of the light coming from the sky is polarized (bees use this phenomenon for navigation). 
The electrons in the air molecules cause a scattering of sunlight in all directions. This explains why the sky is not dark during the day. But when looked at from the sides, the light emitted from a specific electron is totally polarized. Hence, a picture taken in a direction at 90 degrees from the sun can take advantage of this polarization. Actually, the effect is visible in a band of 15° to 30° measured from the optimal direction.
Augustin-Jean Fresnel
But Malus, in the course of his experiments on double refraction, noticed something else: when a ray of light is reflected off a non-metallic surface at the appropriate angle, it behaves like "one" of the two rays emerging from a calcite crystal. It was Malus who coined the term polarization to describe this behavior, although the polarizing angle became known as Brewster's angle after its dependence on the refractive index was determined experimentally by David Brewster in 1815. Malus also introduced the term "plane of polarization". In the case of polarization by reflection, his "plane of polarization" was the plane of the incident and reflected rays; in modern terms, this is the plane "normal" to the "electric" vibration. In 1809, Malus further discovered that the intensity of light passing through "two" polarizers is proportional to the squared cosine of the angle between their planes of polarization (Malus's law), whether the polarizers work by reflection or double refraction, and that "all" birefringent crystals produce both extraordinary refraction and polarization. As the corpuscularists started trying to explain these things in terms of polar "molecules" of light, the wave-theorists had "no working hypothesis" on the nature of polarization, prompting Young to remark that Malus's observations "present greater difficulties to the advocates of the undulatory theory than any other facts with which we are acquainted."
Circular polarization
is the amplitude of the field and
Concentration polarization
Concentration polarization is a term used in the scientific fields of electrochemistry and membrane science.
Circular polarization
where k is the wavenumber,
Photon polarization
Here
Chirality (electromagnetism)
Circular polarization, regarding electromagnetic wave propagation, is polarization such that the tip of the electric field vector describes a helix. The magnitude of the electric field vector is constant. The projection of the tip of the electric field vector upon any fixed plane intersecting, and normal to, the direction of propagation, describes a circle. A circularly polarized wave may be resolved into two linearly polarized waves in phase quadrature with their planes of polarization at right angles to each other. Circular polarization may be referred to as "right-hand" or "left-hand," depending on whether the helix describes the thread of a right-hand or left-hand screw, respectively
Polarization (waves)
Devices that block nearly all of the radiation in one mode are known as "polarizing filters" or simply "polarizers". This corresponds to "g"=0 in the above representation of the Jones matrix. The output of an ideal polarizer is a specific polarization state (usually linear polarization) with an amplitude equal to the input wave's original amplitude in that polarization mode. Power in the other polarization mode is eliminated. Thus if unpolarized light is passed through an ideal polarizer (where "g"=1 and "g"=0) exactly half of its initial power is retained. Practical polarizers, especially inexpensive sheet polarizers, have additional loss so that
"g" < 1. However, in many instances the more relevant figure of merit is the polarizer's degree of polarization or extinction ratio, which involve a comparison of "g" to "g". Since Jones vectors refer to waves' amplitudes (rather than intensity), when illuminated by unpolarized light the remaining power in the unwanted polarization will be ("g"/"g") of the power in the intended polarization.
Circular polarization
Here
Nanofiltration
Concentration polarisation describes the accumulation of the species being retained close to the surface of the membrane which reduces separation capabilities. It occurs because the particles are convected towards the membrane with the solvent and its magnitude is the balance between this convection caused by solvent flux and the particle transport away from the membrane due to the concentration gradient (predominantly caused by diffusion.) Although concentration polarisation is easily reversible, it can lead to fouling of the membrane.
Spin polarization
Spin polarization is the degree to which the spin, i.e., the intrinsic angular momentum of elementary particles, is aligned with a given direction. This property may pertain to the spin, hence to the magnetic moment, of conduction electrons in ferromagnetic metals, such as iron, giving rise to spin-polarized currents. It may refer to (static) spin waves, preferential correlation
of spin orientation with ordered lattices (semiconductors or insulators).
Polarization controller
More general is the transformation of an arbitrary polarization into another arbitrary polarization. This needs three degrees of freedom. Such a polarization controller can for example be obtained by placing on the optical path three rotatable waveplates in cascade: a first quarterwave plate, which is oriented to transform the incident elliptical polarization into linear polarization, a halfwave plate, which transforms this linear polarization into another linear polarization, and a second quarterwave plate, which transforms the other linear polarization into the desired elliptical output polarization.
Dielectric
Ionic polarization is polarization caused by relative displacements between positive and negative ions in ionic crystals (for example, NaCl).
Polarization (politics)
Elite polarization refers to polarization in the party-in-government and party-as-organization. It occurs when party members (both elected government officials and activists within the party organization itself) grow more internally homogenous on policy positions and more divergent relative to members of other parties. Polarized political parties are internally cohesive, unified, programmatic, and ideologically distinct; they are typically found in a parliamentary system of democratic governance.
Polarization (waves)
In many areas of astronomy, the study of polarized electromagnetic radiation from outer space is of great importance. Although not usually a factor in the thermal radiation of stars, polarization is also present in radiation from coherent astronomical sources (e.g. hydroxyl or methanol masers), and incoherent sources such as the large radio lobes in active galaxies, and pulsar radio radiation (which may, it is speculated, sometimes be coherent), and is also imposed upon starlight by scattering from interstellar dust. Apart from providing information on sources of radiation and scattering, polarization also probes the interstellar magnetic field via Faraday rotation. The polarization of the cosmic microwave background is being used to study the physics of the very early universe. Synchrotron radiation is inherently polarised. It has been suggested that astronomical sources caused the chirality of biological molecules on Earth.
Elliptical polarization
Any fixed polarization can be described in terms of the shape and orientation of the polarization ellipse, which is defined by two parameters: axial ratio AR and tilt angle formula_26. The axial ratio is the ratio of the lengths of the major and minor axes of the ellipse, and is always greater than or equal to one.
Polarization (politics)
The vast majority of studies on elite polarization focus on legislative and deliberative bodies. For many years, political scientists measured polarization by examining the ratings of party members published by interest groups, but now, most analyze roll-call voting patterns to determine trends in party-line voting and party unity. Many political scientists studying American politics rely on Poole and Rosenthal's DW-NOMINATE scores, which assign a single liberal-conservative score to each congressperson, enabling comparisons of members from different Congresses. There is much more research on polarization in Congress than on polarization in the other branches of government or in state governments. Azzimonti's political polarization index is more comprehensive instead because it is based on media coverage of newspaper articles reporting political disagreement about policy in all branches of government. Recent work by Gentzkow, Shapiro, and Taddy has used the text of the Congressional Record to document differences in speech patterns between Republicans and Democrats as a measure of polarization. They find that polarization has increased dramatically since 1994.
Polarization (economics)
Because polarization appears similar in 16 European countries as well as the U.S. it seems likely that similar forces affect these shared economic developments. Loss of American manufacturing jobs to overseas global competitors has removed many middle skill jobs. Structural changes with more investment in robotics has removed other middle skill jobs globally, but not the lowest skill or the highest skill. As computers become more competent, this may change. Changes in education in the Third World, with increased education levels in the rest of the world compared to levels in industrial nations, has affected highly industrial economies. Unionization has mixed effects on polarization, since it tends to raise wages at all levels, but reduces the differences between managerial and other employees. The decline in unionization in America may increase polarization slightly. Globalization also lowers wages across the board.The most powerful causes are the redistributive effects of government, through laws such as those that discourage unionization, determine corporate governance, and limit the extent of monopoly rents. These laws generally are plutocratic and accrue benefit to those at the top, at the expense of those in the middle, driving many of the latter into the bottom. As an example of how polarization is affected by labor demand, rather than skill distributions, changing patterns of employment and earnings show strong correlations between wages and the proportion of a skill group employed. When fewer are employed, the wages go down rather than up as simple supply and demand would predict. Another factor is the levelling off of the supply of college graduates after the 1970s in the US and the consequent increase in the wage gap between college graduates and high school graduates. Whether this is also occurring in other industrial countries is not so clear.
Linear polarization
and
Photon polarization
and
Displacement current
The second term on the right hand side, called polarization current density, comes from the change in polarization of the individual molecules of the dielectric material. Polarization results when, under the influence of an applied electric field, the charges in molecules have moved from a position of exact cancellation. The positive and negative charges in molecules separate, causing an increase in the state of polarization P. A changing state of polarization corresponds to charge movement and so is equivalent to a current, hence the term "polarization current".
Rayleigh sky model
The polarization angles show a regular shift in polarization angle with azimuth. For example, when the sun is setting in the West the polarization angles proceed around the horizon. At this time the degree of polarization is constant in circular bands centered around the sun. Thus the degree of polarization as well as its corresponding angle clearly shifts around the horizon. When the sun is located at the zenith the horizon represents a constant degree of polarization. The corresponding polarization angle still shifts with different directions toward the zenith from different points.
Antenna (radio)
In the most general case, polarization is elliptical, meaning that the polarization of the radio waves varies over time. Two special cases are linear polarization (the ellipse collapses into a line) as discussed above, and circular polarization (in which the two axes of the ellipse are equal). In linear polarization the electric field of the radio wave oscillates back and forth along one direction. In circular polarization, the electric field of the radio wave rotates at the radio frequency circularly around the axis of propagation. Circular or elliptically polarized radio waves are designated as right-handed or left-handed using the "thumb in the direction of the propagation" rule. For circular polarization, optical researchers use the opposite right hand rule from the one used by radio engineers.
Polarizer
Generally speaking, and not making direct reference to the above illustration, when either of the two polarizations of circularly polarized light enters the first quarter-wave plate, one of a pair of orthogonal components is retarded by one quarter of a wavelength relative to the other. This creates one of two linear polarizations depending on the handedness the circularly polarized light. The linear polarizer sandwiched between the quarter wave plates is oriented so that it will pass one linear polarization and block the other. The second quarter-wave plate then takes the linearly polarized light that passes and retards the orthogonal component that was not retarded by the previous quarter-wave plate. This brings the two components back into their initial phase relationship, reestablishing the selected circular polarization.
Polarization (waves)
In the important special case of reflection at normal incidence (not involving anisotropic materials) there is no particular "s" or "p" polarization. Both the "x" and "y" polarization components are reflected identically, and therefore the polarization of the reflected wave is identical to that of the incident wave. However, in the case of circular (or elliptical) polarization, the handedness of the polarization state is thereby reversed, since by convention this is specified relative to the direction of propagation. The circular rotation of the electric field around the "x-y" axes called "right-handed" for a wave in the "+z" direction is "left-handed" for a wave in the "-z" direction. But in the general case of reflection at a nonzero angle of incidence, no such generalization can be made. For instance, right-circularly polarized light reflected from a dielectric surface at a grazing angle, will still be right-handed (but elliptically) polarized. Linear polarized light reflected from a metal at non-normal incidence will generally become elliptically polarized. These cases are handled using Jones vectors acted upon by the different Fresnel coefficients for the "s" and "p" polarization components.
Photon polarization
and
Ferroelectricity
When most materials are polarized, the polarization induced, "P", is almost exactly proportional to the applied external electric field "E"; so the polarization is a linear function. This is called dielectric polarization (see figure). Some materials, known as paraelectric materials, show a more enhanced nonlinear polarization (see figure). The electric permittivity, corresponding to the slope of the polarization curve, is not constant as in dielectrics but is a function of the external electric field.
Elliptical polarization
Alternatively, polarization can be represented as a point on the surface of the Poincaré sphere, with formula_27 as the longitude and formula_28 as the latitude, where formula_29. The sign used in the argument of the formula_30 depends on the handedness of the polarization. Positive indicates left hand polarization, while negative indicates right hand polarization, as defined by IEEE.
Polarized light pollution
Polarization is a property of light waves that describes the orientation of their oscillations. Polarized light pollution is a subset of the various forms of light pollution referring specifically to polarized light.
Polarization (waves)
The principle of liquid-crystal display (LCD) technology relies on the rotation of the axis of linear polarization by the liquid crystal array. Light from the backlight (or the back reflective layer, in devices not including or requiring a backlight) first passes through a linear polarizing sheet. That polarized light passes through the actual liquid crystal layer which may be organized in pixels (for a TV or computer monitor) or in another format such as a seven-segment display or one with custom symbols for a particular product. The liquid crystal layer is produced with a consistent right (or left) handed chirality, essentially consisting of tiny helices. This causes circular birefringence, and is engineered so that there is a 90 degree rotation of the linear polarization state. However, when a voltage is applied across a cell, the molecules straighten out, lessening or totally losing the circular birefringence. On the viewing side of the display is another linear polarizing sheet, usually oriented at 90 degrees from the one behind the active layer. Therefore, when the circular birefringence is removed by the application of a sufficient voltage, the polarization of the transmitted light remains at right angles to the front polarizer, and the pixel appears dark. With no voltage, however, the 90 degree rotation of the polarization causes it to exactly match the axis of the front polarizer, allowing the light through. Intermediate voltages create intermediate rotation of the polarization axis and the pixel has an intermediate intensity. Displays based on this principle are widespread, and now are used in the vast majority of televisions, computer monitors and video projectors, rendering the previous CRT technology essentially obsolete. The use of polarization in the operation of LCD displays is immediately apparent to someone wearing polarized sunglasses, often making the display unreadable.
Polarization (politics)
In democracies and other representative governments, citizens vote for the political actors who will represent them. Some scholars argue that political polarization reflects the public's ideology and voting preferences. Dixit and Weibull (2007) claim that political polarization is a natural and regular phenomenon. They argue that there is a link between public differences in ideology and the polarization of representatives, but that an increase in preference differences is usually temporary and ultimately results in compromise.
Polarization (waves)
Circular birefringence is also termed optical activity, especially in chiral fluids, or Faraday rotation, when due to the presence of a magnetic field along the direction of propagation. When linearly polarized light is passed through such an object, it will exit still linearly polarized, but with the axis of polarization rotated. A combination of linear and circular birefringence will have as basis polarizations two orthogonal elliptical polarizations; however, the term "elliptical birefringence" is rarely used.
Polarization in astronomy
Both circular and linear polarization of light from the Sun has been measured. Circular polarization is mainly due to transmission and absorption effects in strongly magnetic regions of the Sun's surface. Another mechanism that gives rise to circular polarization is the so-called "alignment-to-orientation mechanism". Continuum light is linearly polarized at different locations across the face of the Sun (limb polarization) though taken as a whole, this polarization cancels. Linear polarization in spectral lines is usually created by anisotropic scattering of photons on atoms and ions which can themselves be polarized by this interaction. The linearly polarized spectrum of the Sun is often called the second solar spectrum. Atomic polarization can be modified in weak magnetic fields by the Hanle effect. As a result, polarization of the scattered photons is also modified providing a diagnostics tool for understanding stellar magnetic fields.
Polarization (politics)
There are various causes of political polarization and these include political parties, redistricting, the public's political ideology, and the mass media.
Polarimeter
Polarimeters measure this by passing monochromatic light through the first of two polarising plates, creating a polarized beam. This first plate is known as the polarizer. This beam is then rotated as it passes through the sample. After passing through the sample, a second polarizer, known as the analyzer, rotates either via manual rotation or automatic detection of the angle. When the analyzer is rotated such that all the light or no light can pass through, then one can find the angle of rotation which is equal to the angle by which the analyser was rotated(θ) in the former case or (90-θ) in the latter case.
Polarization (waves)
For longitudinal waves such as sound waves in fluids, the direction of oscillation is by definition along the direction of travel, so the issue of polarization is not normally even mentioned. On the other hand, sound waves in a bulk solid can be transverse as well as longitudinal, for a total of three polarization components. In this case, the transverse polarization is associated with the direction of the shear stress and displacement in directions perpendicular to the propagation direction, while the longitudinal polarization describes compression of the solid and vibration along the direction of propagation. The differential propagation of transverse and longitudinal polarizations is important in seismology.
Plane of polarization
Polarization was discovered — but not named or understood — by Huygens, as he investigated the double refraction of "Iceland crystal" (transparent calcite, now called Iceland spar). The essence of his discovery, published in his "Treatise on Light" (1690), was as follows. When a ray (meaning a narrow beam of light) passes through two similarly oriented calcite crystals at normal (perpendicular) incidence, the ordinary ray emerging from the first crystal suffers only the ordinary refraction in the second, while the extraordinary ray emerging from the first suffers only the extraordinary refraction in the second. But when the second crystal is rotated 90° about the incident rays, the roles are interchanged, so that the ordinary ray emerging from the first crystal suffers only the extraordinary refraction in the second, and vice versa. At intermediate positions of the second crystal, each ray emerging from the first is doubly refracted by the second, giving four rays in total; and as the crystal is rotated from the initial orientation to the perpendicular one, the brightnesses of the rays vary, giving a smooth transition between the extreme cases in which there are only two final rays.
Polarization (waves)
Now if one were to introduce a phase shift in between those horizontal and vertical polarization components, one would generally obtain elliptical polarization as is shown in the third figure. When the phase shift is exactly ±90°, then "circular polarization" is produced (fourth and fifth figures). Thus is circular polarization created in practice, starting with linearly polarized light and employing a quarter-wave plate to introduce such a phase shift. The result of two such phase-shifted components in causing a rotating electric field vector is depicted in the animation on the right. Note that circular or elliptical polarization can involve either a clockwise or counterclockwise rotation of the field. These correspond to distinct polarization states, such as the two circular polarizations shown above.
Optics
Light reflected by shiny transparent materials is partly or fully polarised, except when the light is normal (perpendicular) to the surface. It was this effect that allowed the mathematician Étienne-Louis Malus to make the measurements that allowed for his development of the first mathematical models for polarised light. Polarization occurs when light is scattered in the atmosphere. The scattered light produces the brightness and colour in clear skies. This partial polarization of scattered light can be taken advantage of using polarizing filters to darken the sky in photographs. Optical polarization is principally of importance in chemistry due to circular dichroism and optical rotation (""circular birefringence"") exhibited by optically active (chiral) molecules.
Polarization (waves)
All radio (and microwave) antennas used for transmitting or receiving are intrinsically polarized. They transmit in (or receive signals from) a particular polarization, being totally insensitive to the opposite polarization; in certain cases that polarization is a function of direction. Most antennas are nominally linearly polarized, but elliptical and circular polarization is a possibility. As is the convention in optics, the "polarization" of a radio wave is understood to refer to the polarization of its electric field, with the magnetic field being at a 90 degree rotation with respect to it for a linearly polarized wave.
Photon polarization
where
Correlation (projective geometry)
If a correlation "φ" is an involution (that is, two applications of the correlation equals the identity: for all points "P") then it is called a polarity. Polarities of projective spaces lead to polar spaces, which are defined by taking the collection of all subspace which are contained in their image under the polarity.
Photon polarization
and
Chandrasekhar polarization
Chandrasekhar published series of 26 papers in The Astrophysical Journal titled "On the Radiative Equilibrium of a Stellar Atmosphere" from 1944 to 1948. In the 10th paper, he predicted that the purely electron stellar atmosphere emits a polarized light using Thomson law of scattering. The theory predicted that 11 percent polarization could be observed at maximum. But when this is applied to a spherical star, the net polarization effect was found to be zero, because of the spherical symmetry. But it took another 20 years to explain under what conditions this polarization can be observed. J. Patrick Harrington and George W. Collins, II showed that this symmetry is broken if we consider a rapidly rotating star (or a binary star system), in which the star is not exactly spherical, but slightly oblate due to extreme rotation (or tidal distortion in the case of binary system). The symmetry is also broken in eclipsing binary star system.
Polarization (economics)
Although "polarization" is a relatively young concept in economic analysis, the phenomenon of wage and labor skill polarization is as old as economics. More recently economic polarization has been connected to both automation and the export of jobs to low wage countries. Many middle-skilled jobs are routine and demand only average skills and abilities. As a result, current computer technologies are able to handle them, or, alternatively, they can be outsourced electronically to foreign websites to be performed by comparatively low-wage workers.
Polarization (electrochemistry)
The term 'polarization' derives from the early 19th-century discovery that electrolysis causes the elements in an electrolyte to be attracted towards one or the other pole i.e. the gasses were "polarized" towards the electrodes. Thus, initially 'polarization' was essentially a description of electrolysis itself, and in the context of electrochemical cells used to describe the effects on the electrolyte (which was then called "polarization liquid"). In time, as more electrochemical processes were invented, the term 'polarization' evolved to denote any (potentially undesirable) mechanical side-effects that occur at the interface between electrolyte and electrodes.
Polarizer
where "I" is the initial intensity and "θ" is the angle between the light's initial polarization direction and the axis of the polarizer.
Circular polarization
Using this convention, polarization is defined from the point of view of the source. When using this convention, left or right handedness is determined by pointing one's left or right thumb away from the source, in the same direction that the wave is propagating, and matching the curling of one's fingers to the direction of the spatial rotation of the field at a given point in space. When determining if the wave is clockwise or anti-clockwise circularly polarized, one again takes the point of view of the source, and while looking away from the source and in the same direction of the wave's propagation, one observes the direction of the field's spatial rotation.