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Topic: Circular polarization


  
  Circular polarization selective surface made of resonant spirals - Patent 5280298
A circular polarization selective surface as defined claim 3, wherein a number of the spirals are arranged parallel to each other in a single plane and all their central segments are parallel and perpendicular to the plane.
A circular polarization selective surface as defined claim 9, wherein a number of the spirals are arranged parallel to each other in a single plane and all their central segments are parallel and perpendicular to the plane.
A circular polarization selective surface as defined claim 14, wherein a number of the spirals are arranged parallel to each other in a single plane and all their central segments are parallel and perpendicular to the plane.
www.freepatentsonline.com /5280298.html   (2684 words)

  
 Polarization
Light is linearly polarized when its E-field component is in a plane.
Circular and elliptical polarization occurs when two or more linearly polarized waves add together such that the E-field of the net wave rotates.
For elliptically polarized light both the magnitude and the direction of the E-field varies.
webphysics.davidson.edu /physlet_resources/dav_optics/Examples/polarization.html   (330 words)

  
  PIRA 6H30.00 CIRCULAR POLARIZATION   (Site not responding. Last check: )
A beam of polarized light is rotated when directed up a vertical tube filled with sugar solution.
Pass a polarized laser beam through a cylinder filled with a quinine sulfate solution.
Polarized light is passed through holes in an electromagnet bored parallel with the magnetic field.
www.physics.ncsu.edu /pira/6optics/6H30.html   (322 words)

  
  BYU Photonics - Polarization and Polarimetric Testing
Circular polarized light describes any light where the relative amplitudes are the same and there is a phase shift of exactly ninety degrees.
Circular polarized light is commonly launched into the fiber in order to reduce orientation dependence of the launching end.
The relative phase of the detected light is displayed as latitude on the sphere with circular polarizations at the poles.
www.ee.byu.edu /photonics/polarization.phtml   (937 words)

  
 Relation between measurements in circular and linear polarization bases.
Measurements in a circular polarization basis are characterized by the covariances W
to the polarization characteristics of the propagation and scattering medium.
The relations have formed the basis for interpreting circular polarization measurements in a number of studies (e.g., McCormick and Hendry, 1975, 1979; Hendry and Antar, 1984; Bringi and Hendry, 1990; Metcalf, 1995, 1997); Krehbiel et al., 1996) but are conceptually and analytically difficult to understand.
ibis.nmt.edu /nmt_lms/jtech/node15.html   (740 words)

  
 Circular polarization - Wikipedia, the free encyclopedia
In electrodynamics, circular polarization of electromagnetic radiation is a polarization such that the tip of the electric field vector, at a fixed point in space, describes a circle as time progresses.
The term "circular polarization" is often used erroneously to describe mixed polarity signals used mostly in FM radio (87.5 to 108.0 MHz), where a vertical and a horizontal component are propagated simultaneously by a single or a combined array.
As a consequence, circular dichroism is exhibited by biological molecules, because of the dextrorotary (e.g.
en.wikipedia.org /wiki/Circular_polarization   (599 words)

  
 Polarization
Polarized light is produced when the direction of E in the plane perpendicular to the direction of propagation is constrained in some fashion.
The light is elliptically polarized, then the two components have a constant phase difference, and the tip of the electric field vector traces out an ellipse in the plane perpendicular to the direction of propagation.
The polarization of the extraordinary ray lies in the plane containing the direction of propagation and the optic axis, and the polarization of the ordinary ray is perpendicular to this plane.
electron9.phys.utk.edu /optics421/modules/m8/polarization.htm   (1651 words)

  
 Circular Polarization
A linear polarizing filter followed by a quarter-wave plate, whose slow and fast axes are at 45° to the axis of the polarizer, becomes a circular polarizing filter and incident unpolarized light emerges as circularly polarized light.
The circular polarization produced by the linear polarizer/quarter-wave plate sandwich is made evident by placing a mirror behind it and looking through the circular polarizer at the mirror reflection.
Circular polarizers are used for just this very purpose -- to reduce annoying reflections, eliminate glare, and enhance contrast for a variety of commercial applications.
www.fas.harvard.edu /~scdiroff/lds/LightOptics/CircularPolarization/CircularPolarization.html   (737 words)

  
 A.H. Systems - Antenna Terms and Definitions
Polarization: Polarization is defined as the orientation of the electric field of an electromagnetic wave.
In circular polarization the electric field vector appears to be rotating with circular motion about the direction of propagation, making one full turn for each RF cycle.
Circular polarization has also been found to be of advantage in some microwave radar applications to minimize the "clutter" echoes received from raindrops, in relation to the echoes from larger targets such as aircraft.
www.ahsystems.com /notes/Terms_and_Definitions.php   (844 words)

  
 Polarizer - Camerapedia.org
A circular polarizing filter is nothing more than a linear polarizer, with the addition of a quarter-wave plate (QWP) which converts the linear polarization of light passing through the polarizing filter to circular polarization.
A circular polarizer is able to block all photons rotating in one direction while allowing those going in the other direction to pass.
With a polarizing filter attached, the ratio of reflected/transmitted light (fixed for non-polarized light) varies with the polarization plane orientation of polarized light, relative to the beam-splitter, causing the amount of light reaching the autofocus sensor to vary.
www.camerapedia.org /wiki/Polarizer   (1060 words)

  
 Haidinger's brush: the unknown sense
Thus, horizontal polarization causes a vertical (with respect to the ground) yellow brush irrespective of the inclination of the head.
The way of distinguishing between circular polarized light and slanted linearly polarized light is, of course, to lean the head sidewise and note if the brush is fixed with respect to the source of light or to the eyes.
Some observers are able to see the change in sky polarization that occurs close to the sun, where the yellow branches can be tangential to the sun instead of radial (see Brewster's point), in spite of the lower degree of polarization and background brightness (the sun should be blocked, of course).
www.polarization.com /haidinger/haidinger.html   (1697 words)

  
 Using a polarizer effectively without TTL control
If the direction of maximum polarization is within ~45° of the horizontal, and you happen to be wearing polarized sunglasses, pan and tilt your head until you get maximum effect, then match the pan with your camera angle and align your polarizer's blocking direction with the right-left axis of the glasses.
Polarized sunglasses are always constructed such that the blocking axes of both lenses run right to left as the glasses are meant to be worn.
Polarizers aren't always clearly marked, but thanks to an RPD tip from Dennis Duke, it's easy to tell whether a polarizer in hand is circular or linear.
dpfwiw.com /polarizer.htm   (8130 words)

  
 States of Polarization - Linear, Circular and Elliptical Polarization
The polarization state is one of the fundamental characteristics that is required to study light.
If the polarization of all the electromagnetic waves in a light beam can be made so that each of the electric or magnetic field vector to have the same orientation, then the light beam is said to be polarized.
Circular polarization can be described as the vectors of the electric field is rotated at a point in space in the direction that is perpendicular to the plane of propagation, instead of fixed orientation oscillation.
www.azooptics.com /Details.asp?ArticleID=65   (338 words)

  
 Circular Polarization in M81
We report the detection of circular polarization in the compact radio jet of the nearby spiral galaxy M81 (M81*).
This further supports the idea that M81* is a scaled-up version of Sgr A* and suggests that the polarization properties are intrinsic to the two sources and are not caused by a foreground screen in the Galaxy.
M81* is unpolarized in the linear sense at a frequency as high as 86 GHz and shows variable circular polarization at a frequency as high as 15 GHz.
www.mpifr-bonn.mpg.de /staff/abrunthaler/m81.shtml   (385 words)

  
 Meadowlark Optics Circular Polarizers | Circular Polarizers/Isolators
Circular polarizers transmit either left-circular or right-circular polarized light for an input beam of any polarization state.
Therefore, the same polarizer that produces circular polarization of the incident beam will block the return beam with an isolation of at least 99.8 percent.
Achieving optical isolation using Meadowlark’s circular polarizers requires that a given reflection be specular and that there is no medium intervening between the reflector and optical isolator to cause significant depolarization or polarization modification.
www.meadowlark.com /products/CircularPolarizersLanding.php   (146 words)

  
 Elec. Spin Polariza. Determin. from Lumines. Polari.   (Site not responding. Last check: )
3, additional factors must be considered in connecting the polarization of the detected light to the electron spin density in the semiconductor: i) the angle of the light emitted in the GaAs with respect to the quantization axis; and ii) the change in circular polarization of the light passing through the interface.
A third, the polarization of the conductivity, describes the transport in bulk ferromagnets, and a fourth, the polarization of the interface conductance, describes the transport through the interface.
For example, the polarization of the Fermi level density of states for Fe is positive, and the polarization of the conductivity is negative.
physics.nist.gov /Divisions/Div841/Gp3/Projects/MagNano/esp.html   (1281 words)

  
 Definition: circular polarization   (Site not responding. Last check: )
circular polarization: In electromagnetic wave propagation, polarization such that the tip of the electric field vector describes a helix.
Note 3: 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.
Note 4: 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.
www.its.bldrdoc.gov /projects/devglossary/_circular_polarization.html   (129 words)

  
 Polarization Summary
The simplest manifestation of polarization to visualize is that of a plane wave, which is a good approximation to most light waves (a plane wave is a wave with infinitely long and wide wavefronts).
Polarization is principally of importance in chemistry due to the circular dichroism and "optical rotation" (circular birefringence) exhibited by optically active (chiral) molecules.
Polarization is also used for some 3D movies, in which the two images for the two eyes are polarized differently, and special filter glasses are used to only present the correct image to the correct eye.
www.bookrags.com /Polarization   (5331 words)

  
 Polarization - Wikipedia, the free encyclopedia
The simplest manifestation of polarization to visualize is that of a plane wave, which is a good approximation to most light waves (a plane wave is a wave with infinitely long and wide wavefronts).
Polarization is principally of importance in chemistry due to the circular dichroism and "optical rotation" (circular birefringence) exhibited by optically active (chiral) molecules.
Polarization is also used for some 3D movies, in which the two images for the two eyes are polarized differently, and special filter glasses are used to only present the correct image to the correct eye.
en.wikipedia.org /wiki/Polarization   (4463 words)

  
 MMA Memo 208: Polarization Calibration of the MMA: Circular versus Linear Feeds
Calibration of interferometers with circularly polarized feeds is only weakly affected by the polarization of typical calibrators whereas interferometers using linearly polarized feeds suffers from significant coupling of calibrator polarization and the determination of gains.
Since the polarization state of the phase calibration source is usually unknown it must be estimated jointly with the instrumental polarization.
Fortunately, the variable parallactic angle of an alt-az antenna mount causes the source polarization to rotate on the sky whereas the instrumental polarization is fixed to the antenna.
www.cv.nrao.edu /alma/almaweb/www/memos/html-memos/alma208/memo208.html   (3567 words)

  
 Circular polarization: change of sign
Calculations made for spheroidal particles show that the position where the circular polarization changes the sign shifts with variations of the particle inclination in the same manner as the position of
It is important that from the point of view of circular polarization there exists a large difference between prolate and oblate grains.
Note also that the circular polarization observed for stars indicates the complex structure of interstellar magnetic fields in their directions and gives information on the birefringence in the dust cloud nearest to the observer.
www.astro.spbu.ru /DOP/8-GLIB/ASTNOTES/node8.html   (506 words)

  
 Introduction to Spontaneous Polarization and Hysteresis
Atoms of cesium contained in the cylindrical cell are spin polarized (the vertical arrows represent the atomic spins) by absorbing some of the laser light incident upon them (the large arrow passing through the cell).
This rotation is detected by next passing the probe beam though an analyzing polarizer at 45 degrees to its initial polarization, producing a light intensity on a photdiode detector which is roughly proportional to the atomic polarization (for small rotations).
The horizontal axis shows the degree of circular polarization of the pump beam (the light which is causing the atomic spin polarization).
www.phys.washington.edu /users/andalkar/Introduction.html   (659 words)

  
 Antenna Polarization Application Note - Joseph H. Reisert   (Site not responding. Last check: )
In a circular polarized antenna, the plane of polarization rotates in a circle making one complete revolution during one period of the wave.
This is particularly desired since the polarization of a linear polarized radio wave may be rotated as the signal passes through any anomalies (such as Faraday rotation) in the ionosphere.
Circular polarization has been used to an advantage in these situations since the reflected wave would have a different sense than the direct wave and block the fading from these reflections.
www.astronwireless.com /polarization.html   (1534 words)

  
 Woollam Spectroscopic Ellipsometers and Thin Film Characterization
The polarization state of a wave is defined by the orientation and the phase of the E-field vector of a wave.
Circular polarized wave: one component is at a maximum while the other is at a minimum.
Linear and circular polarization are actually subsets of elliptical polarization.
www.jawoollam.com /tutorial_polarization.html   (437 words)

  
 Circular Polarization States for Light, and quarter-wave Plates
In principle there are two sorts of circular polarization; the one where the electric vector rotates to the right and the one where it rotates to the left, referred to as left-circular and right-circular polarizations.
As we know from the textbook, there are particular materials, known as polarizers, that selectively absorb light that has its electric field in a certain direction, while passing light directly on when its electric field is polarized in the perpendicular direction.
The light exiting this polarizer would then be plane polarized, and have less intensity than when it entered since a portion of its energy had been absorbed.
panda.unm.edu /Courses/Finley/P262/CircPolar2/CircPolar2.html   (1596 words)

  
 Antenna Polarization | Air-Stream
Circular polarized wave radiates energy in both the horizontal and vertical planes and all planes in between.
Polarization is an important design consideration, as each antenna in a system should be properly aligned for maximum signal strength between stations.
Vertical polarization is most commonly used when it is desired to radiate a radio signal in all directions over a short to medium range.
www.air-stream.org /Polarization   (1110 words)

  
 POLARIZATION
The polarization of an electromagnetic wave is defined as the orientation of the electric field vector.
The polarization is described by the geometric figure traced by the electric field vector upon a stationary plane perpendicular to the direction of propagation, as the wave travels through that plane.
For a linearly polarized antenna, the radiation pattern is taken both for a co-polarized and cross polarized response.
www.kyes.com /antenna/navy/polarization/polariza.htm   (992 words)

  
 Relation between measurements in circular and linear polarization bases.
The relations have formed the basis for interpreting circular polarization measurements in a number of studies (e.g., McCormick and Hendry, 1975, 1979; Hendry and Antar, 1984; Bringi and Hendry, 1990; Metcalf, 1995, 1997); Krehbiel et al., 1996) but are conceptually and analytically difficult to understand.
corresponds to the total signal power (polarized plus unpolarized), both the tangent and the projection points are on the surface of the outer, total power sphere, while the polarization state itself is on the inner, Poincaré sphere (see Figure 4).
Circular polarization measurements can be well represented in covariance or Poincaré sphere space (Torlaschi and Holt, 1993, 1998; Krehbiel and Scott, 1999).
www.lightning.nmt.edu /nmt_lms/jtech/node15.html   (740 words)

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