Spin photocurrents generated by homogeneous optical excitation with circularly polarized radiation in quantum wells (QWs) are reviewed. The absorption of circularly polarized light results in optical spin orientation due to the transfer of the angular momentum of photons to electrons of a two-dimensional electron gas (2DEG). It is shown that in quantum wells belonging to one of the gyrotropic c...

Spin photocurrents generated by homogeneous optical excitation with circularly polarized radiation in quantum wells (QWs) are reviewed. The absorption of circularly polarized light results in optical spin orientation due to the transfer of the angular momentum of photons to electrons of a two-dimensional electron gas (2DEG). It is shown that in quantum wells belonging to one of the gyrotropic c...

We investigate numerically and experimentally the spatial collapse dynamics and polarization stability of radially and azimuthally polarized vortex beams in pure Kerr medium. These beams are unstable to azimuthal modulation instabilities and break up into distinct collapsing filaments. The polarization of the filaments is primarily linear with weak circular components at the filaments' boundari...

A novel type of circularly polarized broadband antenna consisting of a modified circular wideslot aperture and an L-shaped feed probe is introduced. The modified circular wide-slot is partially covered to generate circular polarization with broadband characteristics in the axial ratio. Variations in both the axial ratio and the S11 characteristics of the device are investigated and radiation pa...

We report on polarimetric observations of 100 pulsars centered on 774 MHz, made using the Green Bank Telescope, presenting their polarization profiles and polarized flux densities and comparing them with previous observations when possible. For 67 pulsars, these are the first such measurements made. Polarization profiles of 8 millisecond pulsars in our sample show wide profiles and flat positio...

We calculate the linear and circular polarization of gluons radiated off top quarks produced in e + e −-annihilations. For typical top pair production energies at the Next-Linear-Collider (NLC) the degree of linear polarization remains close to its soft gluon value of 100% over almost the whole energy spectrum of the gluon. The circular polarization is largest for maximal gluon energies where t...

This report describes the design, construction, and operation of a monitor of the transverse polarization of beams circulating in the Stanford Linear Accelerator Center e+estorage ring SPEAR. This device measures an asymmetry in the Compton scattering of circularly polarized laser photons. Measurement of the beam polarization to a statistical precision of _+5% requires approximately two minutes...

We summarize the current state of polarization observations of Sagittarius A*, the compact radio source and supermassive black hole candidate in the Galactic Center. These observations are providing new tools for understanding accretion disks, jets and their environments. Linear polarization observations have shown that Sgr A* is unpolarized at frequencies as high as 86 GHz. However, recent sin...

At present three pulsars are known which clearly show a strongly increasing degree of circular polarization with frequency. As this is accompanied by a smooth decrease of linear polarization, we investigate, if this observation can be explained through a propagation mode transition from linear to circular polarization. Using a previously published model we find that the rate of change of the po...

There is a need for improved antenna performance in view of a recent decision by the DOD to disable SA at L1 GPS channel. For single frequency receivers SA had been the main cause of the largest errors of code and carrier phase measurements. With SA turned off, the multipath, ionosphere and antenna phase center variations are now the biggest contributors to code and carrier phase measurements. ...