Circular polarization

About: Circular polarization is a research topic. Over the lifetime, 15201 publications have been published within this topic receiving 234418 citations.

Manifestation of coherent spin precession in stimulated semiconductor emission dynamics

Abstract: Circularly polarized optical excitation of a semiconductor microcavity in a transverse magnetic field leads to pulsed laser emission with alternating circular polarization synchronized to the electron Larmor precession. The synchronization originates from the transfer of electron-spin coherence to the dynamics of the optical field. A microscopic theory is developed to analyze the coupled carrier--light-field dynamics.

Temperature-dependent tilt angle in the smectic C phase of a liquid crystal

Abstract: Liquid crystal smectic C phase temperature dependent tilt angle, using conoscopic observation and circularly polarized light

Profile and polarization characteristics of energetic pulsars

Abstract: In this paper, we compare the characteristics of pulsars with a high spin-down energy-loss rate (E) against those with a low E. We show that the differences in the total intensity pulse morphology between the two classes are in general rather subtle. A much more significant difference is the fractional polarization which is very high for high E pulsars and low for low E pulsars. The E at the transition is very similar to the death line predicted for curvature radiation. This suggests a possible link between high energy and radio emission in pulsars and could imply that γ-ray efficiency is correlated with the degree of linear polarization in the radio band. The degree of circular polarization is in general higher in the second component of doubles, which is possibly caused by the effect of corotation on the curvature of the field lines in the inertial observer frame. The most direct link between the high-energy emission and the radio emission could be the subgroup of pulsars which we call the energetic wide beam pulsars. These young pulsars have very wide profiles with steep edges and are likely to be emitted from a single magnetic pole. The similarities with the high-energy profiles suggest that both types of emission are produced at the same extended height range in the magnetosphere. Alternatively, the beams of the energetic wide beam pulsars could be magnified by propagation effects in the magnetosphere. This would naturally lead to decoupling of the wave modes, which could explain the high degree of linear polarization. As part of this study, we have discovered three previously unknown interpulse pulsars (and we detected one for the first time at 20 cm). We also obtained rotation measures for 18 pulsars whose values had not previously been measured.

Microwave antenna system

Abstract: An antenna for use in propagating or receiving microwave radiation having both left-hand and right-hand circular polarization. The left-hand and right-hand circularly polarized radiation may be transmitted or received simultaneously without interference with one another, that is, they are isolated from one another by 27 dB or more. The preferred antenna comprises an array of closely clustered waveguide elements each of which converts respective linearly polarized signals to left-hand and right-hand circularly polarized signals and vice versa. Isolation means also are provided in each of the waveguide elements for preventing radiation either propagated or received by a waveguide element from being coupled into the radiation being propagated or received by other waveguide elements in the array. Preferably, square waveguide is utilized for the array elements and the isolation is provided by a plurality of conductive elements mounted on each of the open ends of the waveguide elements. The cluster array of waveguide elements may include dummy elements, may be fed with electromagnetic signals having various phase and power differences to produce desired radiation transmission or reception patterns and may be used to illuminate a parabolic reflector having a secondary radiation pattern. A single waveguide element or an array of them may be used in communications satellites and the like or may be used in radar or other applications.