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Showing papers on "Polarization rotator published in 1974"



Patent
24 Apr 1974
TL;DR: In this paper, an optical data communication system is provided whereby two orthogonal polarization states of a light beam carrier correspond to digital states, and automatic polarization compensation is provided by applying a dither modulating voltage to a cell exhibiting the electro-optic effect.
Abstract: An optical data communication system is provided whereby two orthogonal polarization states of a light beam carrier correspond to digital states. In such a system, automatic polarization compensation is provided by applying a dither modulating voltage to a cell exhibiting the electro-optic effect. The cell controls the relative phase of electric field components of an input light beam enabling the dither frequency component of the difference of the instantaneous powers in the two polarization states to be coherently detected. A signal derived from the coherent detection process is fed back to the cell via an integrator to form polarization bias compensating servo loop of Type I.

43 citations



Journal ArticleDOI
TL;DR: In this article, the feasibility of obtaining arbitrary polarization in both one and two-dimensional arrays of slots in dual mode bifurcated waveguides was demonstrated, where the radiating element consists of a pair of crossed slots in the sidewall of a rectangular waveguide that couple to even and odd waveguide modes.
Abstract: The feasibility of obtaining arbitrary polarization in both one- and two-dimensional arrays of slots in dual mode bifurcated Waveguides has been demonstrated. The radiating element consists of a pair of crossed slots in the sidewall of a bifurcated rectangular waveguide that couple to even and odd waveguide modes. One linear polarization is excited by the even or "sum" mode and the orthogonal linear polarization is excited by the odd or "difference" mode. By superposing the sum and difference modes in the proper amplitude and phase, any arbitrary polarization can be realized. A two-dimensional array consisting of eight waveguide linear arrays, ferrite phase shifters for scanning in the plane normal to the linear arrays, and a feed network for power distribution and polarization control was constructed. Good radiation performance for various polarizations was obtained. In the case of linear polarization, the cross polarization component was on the order of -25 dB and in the case of circular polarization, the axial ratio was on the order of 1 dB. The polarization was controlled with a ferrite phase shifter. Close-in sidelobes of better than 20 dB were obtained for all polarizations. The preceding performance characteristics were obtained over a scan range of \pm20\deg and over a 6 percent frequency band.

17 citations


Journal ArticleDOI
TL;DR: In this article, the orientation of the plane of polarization as well as the degree of linear polarization of γ-radiation was investigated in an external magnetic field with respect to an external magnetometer.

16 citations


Patent
29 Oct 1974
TL;DR: In this article, the authors describe a signal receiving system that includes control apparatus for making system phase angle track the orientation angle of linear polarization of a radiated carrier, and for keeping substantially small any phase and amplitude distortions of the carrier which result from undesired polarization modulation.
Abstract: The described signal receiving system includes control apparatus for making system phase angle track the orientation angle of linear polarization of a radiated carrier, and for keeping substantially small any phase and amplitude distortions of the carrier which result from undesired polarization modulation.

7 citations


Journal ArticleDOI
TL;DR: In this article, the authors used the Crab Nebula as a background source of linearly polarized light and investigated the birefringence by measurements of circular polarization in a sinusoidal fashion characteristic of a wave plate with the orientation expected from independent measurements of the interstellar linear polarization in the same direction.
Abstract: The interstellar medium may be regarded as a weak wave plate, the linear birefringence arising from the aligned grains which produce interstellar linear polarization. Using the Crab Nebula as a background source of linearly polarized light we have investigated this birefringence by measurements of circular polarization. The circular component is found to vary with the intrinsic linear polarization in a sinusoidal fashion characteristic of a wave plate with the orientation expected from independent measurements of the interstellar linear polarization in the same direction. Measurements of the wavelength dependence, together with the sense and magnitude of the circular polarization are interpreted as evidence for the dielectric nature of the interstellar grain materials. These observations provide a firm basis for a similar interpretation of the circular polarization of reddened stars. The observations of the stars can then be used to study the grain composition and the structure of the magnetic field in many directions in the Galaxy.

5 citations


Journal ArticleDOI
TL;DR: In this article, expressions for the intensity, azimuth, ellipticity, and degree of polarization as functions of the path difference, the optical parameters of the elements, and the partial polarization state of the light entering the instrument were developed.

2 citations


Journal ArticleDOI
TL;DR: In this article, the influence of uniaxial compression on the polarization of the radiation emitted by a double-sided heterostructure laser pumped with a current which exceeded the threshold by a factor of 3.
Abstract: An investigation was made of the influence of uniaxial compression on the polarization of the radiation emitted by a double-sided heterostructure laser pumped with a current which exceeded the threshold by a factor of 3. The degree of polarization was in excess of 0.8. The pressure which altered the polarization to the perpendicular direction was determined.

2 citations



Journal ArticleDOI
TL;DR: In this paper, the effects of screened Coulomb scattering on electron polarization were calculated. But the results applied to elastic electron scattering by light atoms at moderate energies, and they were carried out to second order in αZ; in this order the change in magnitude of the polarization first occurs.
Abstract: In this paper the effects of screened‐Coulomb scattering on electron polarization are calculated. The results apply to elastic electron scattering by light atoms at moderate energies. The calculation is carried out to second order in αZ; in this order the change in magnitude of the polarization first occurs. For arbitrary initial polarization, the final polarization vector is expressed explicitly as a function of initial polarization, momentum, and scattering angle. The effects of screening on polarization is discussed. In the low energy region, a few hundred eV, there is a significant effect on the output polarization of an input unpolarized beam.


Journal ArticleDOI
TL;DR: In this article, the influence of the limit of integration of the angles on the asymmetry ratio in the detection of circular polarization by pair production was studied, and it was shown that the limit is positively correlated with the number of angles.
Abstract: We study the influence of the limit of integration of the angles on the asymmetry ratio in the detection of circular polarization by pair production.