Polarization aberrations of laser radiation

Polarization aberrations (PAs) of laser radiation, defined as distortions of the wave-polarization characteristics, are considered within the framework of wave theory. The parameters describing these aberrations are introduced. It is established that PAs already appear in the paraxial region. PAs of a thin lens are calculated using the method of wave-polarization matrices. It is shown that, under certain conditions, the polarization state is modified at the axis of the laser beam.     

Polarization properties of boson radiation

The polarization properties of boson radiation in a magnetic field have been studied, and expressions obtained for the integral intensity of boson and fermion radiation in a magnetic field which are suitable for random energies. The investigation of boson radiation in an external field is of limited practical interest; however, from the methodological point of view it is very instructive and has already been investigated by several authors [1, 2, 4], Also of undoubted interest is the comparison of boson and fermion (electron) radiation and hence the explanation of the role of spin in radiation.In conclusion the author expresses his deep appreciation to Prof. I, M. Ternov for assistance with the work and discussion of the results.     

Polarization of line radiation in the presence of external electric quadrupole and uniform magnetic fields

The polarization of emission lines formed in a medium immersed in external electric and magnetic fields is studied. The electric field is assumed to be quadrupolar in nature, while the magnetic field is uniform. We show that the quadrupole electric field produces line splitting which is characteristically different from the Zeeman effect. While the line components emitted along the quantization axis are circularly polarized in Zeeman effect, they are, in contrast, linearly polarized in the case of a pure quadrupole electric field. The emission perpendicular to the quantization axis produces three linearly polarized components in Zeeman effect, whereas only two linearly polarized components are observed in the case of quadrupole electric fields. Lack of azimuthal symmetry in the quadrupole electric field leads to polarized line components which appear quite differently for different azimuthal angles of the line of sight.     

Polarization indicatrices for synchrotron radiation

Results are presented on the instantaneous angular distribution of the polarization components in relation to the direction of the polarization vector.     

Polarization of radiation under superradiance conditions

A theoretical study is made of the polarization properties of superradiance emitted by gases in a high-current longitudinal discharge. It is shown that the Zeeman effect in the discharge current makes the radiation at the periphery of a light beam totally polarized. Formulas are derived for relating the degree of polarization of a light beam with the dependences of the gain profile on the frequency and on the transverse coordinate. An analysis is made of the influence of diffraction on the polarization properties of a light beam and the anisotropic waveguide modes are found. A calculation is made of the distribution of the intensity of the optical field when radiation is generated between crossed Polaroids at the exit end of the discharge tube.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 51–56, May, 1980.The authors are grateful to A. I. Odintsov and V. P. Yakunin for frequent discussions.     

Polarization qubit phase gate in driven atomic media

We present here an all-optical scheme for the experimental realization of a quantum phase gate. It is based on the polarization degree of freedom of two traveling single-photon wave packets and exploits giant Kerr nonlinearities that can be attained in coherently driven ultracold atomic media.     

Polarization of the cosmic microwave background radiation

In re-ionized models, the measurement of polarization of CMBR can be a good criterion to narrow down the parameter space for cosmological models. A Vishniac-type effect in second order polarization over arc minute scales has been calculated. It has been shown that while the effect is very small (∼10⁻² μK) for CDM models, it can be significant (∼0.3μK) for some isocurvature models.     

Polarization of excited nuclear levels induced by atomic orientation

The effect of atomic orientation produced in a tilted-foil geometry on the angular correlation of nuclear decay -rays is investigated. A quantum mechanical treatment is presented for the case of a known electronic ensemble. An approximate, phenomenological approach is suggested for heavy ions recoiling out of the target with a multi-electron complex environment. The utilization of this approach in hyperfine interaction experiments is discussed.Supported in part by the United States-Israel Binational Science Foundation.Incumbent of the Charles H. Revson Foundation Career Development Chair.     

The radiation of atomic negative ions

A survey is made of the experimental research program at the Fermi National Accelerator Laboratory covering the approved experimental proposals. These experiments are divided into physics topics and a comparison is made of the kinematic ranges of the measurements and the techniques used.     

Polarization of non-parallel rays of infra-red radiation by reflection

The paper studies the possibilities of polarizing strongly divergent or convergent beams of infra-red rays from the point of view of the purity of the radiation obtained, the efficiency of the process and the required dimensions of the germanium mirrors. The problem is solved by using double reflection on germanium mirrors with different angle of incidence in the neighbourhood of the Brewster angle. The proposed arrangements are able to treat infra-red radiation in a range of 2 to 100 — according to the quality of the germanium used. The volume of radiation of the undesirable direction of vibration may be smaller than 1% for a solid angle of the divergent beam of 20° × 70°. At angles of divergence of 14° × 30° its volume decreases to a value smaller than 1 The efficiency of these arrangements is about 60% of the ideal value and the use of germanium is very economical.The author is greatly indebted to Dr. J. Tauc for instigating this study.     

Polarization dependence of the spontaneous radiation of hot electrons

This paper reports on the results of investigations into the polarization dependence of the spontaneous radiation of hot electrons due to their intervalley redistribution in multivalley semiconductors. It is demonstrated that the radiation is predominantly polarized normally to the electric field and the direction of polarization and its intensity can vary according to the degree of electron redistribution, the electron concentration, and the heating electric field.     

Polarization of thermal microwave radiation of the cloudy atmosphere

We present the results of an experimental studies of the microwave radiation of the cloudy atmosphere indicating the presence of significant polarization contrasts in the radiation of the winter-spring clouds. The interpretation of the experimental data is made on the basis of a model of microwave radiation transfer in mixed-type clouds consisting of crystals and supercooled water drops. Radiophysical Research Institute, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 43, No. 5, pp. 395–405, May., 2000.     

Polarization properties of surface plasma radiation excited by electrons

Some interesting features of the radiation associated with non-radiative surface plasmons, excited by electrons have not been explained previously. We give here an explanation of the origins of these features, based on recent work by Elson and Ritchie.     

Polarization of atomic hydrogen lines upon collision with an electron beam

A technique is described for the analytical calculation of the degree of linear polarization of atomic hydrogen lines formed by several radiative transitions with different polarizations upon excitation by an electron impact. The degree of linear polarization of the line L of the hydrogen atom is calculated as an example. The analytical equations used are derived by the Born method. The results of the analytical calculation are compared with experiment and with other calculations. The effective excitation cross sections and the degree of linear polarization of the H_α and H_β lines of the hydrogen atom are calculated analytically for the case of electron-beam excitation. The results of the analytical calculation of the effective excitation cross section of the H_α line are compared with the available experimental and calculated data.     

Polarization spectroscopy of atomic oxygen by dye and semiconductor diode lasers

Summary We used polarization spectroscopy to perform a high-resolution investigation of atomic oxygen in the visible and near-infrared spectral region by means of dye and semiconductor diode lasers. We measured the fine structure of the highly excited 4d ⁵ D level and resolved the hyperfine structure of the metastable 3s ⁵ S ₂ level of¹⁷O. Isotope shift values are also reported for several transitions of the three stable oxygen isotopes (¹⁶O,¹⁷O,¹⁸O). Polarization lineshapes are discussed and compared with those obtained in saturation techniques.     

Polarization visualization of scattering media with CW laser radiation

The method of polarization visualization of a multiply scattering medium containing macroinhomogeneities based on analysis of polarization spatial distribution of a scattered linearly polarized light is discussed. The treatment is based on statistical properties of the effective optical path distribution of scattered field components. The influence of media scattering properties and the geometry of the experiment on the inhomogeneity image contrast obtained with use of polarization degree and of normalized scattered intensity of radiation as visualization parameters are discussed, as well as spatial resolution achieved in these both cases. Using the results of theoretical analysis and of the experimental model, the relationship between the shapes of spatial distributions of polarization degree and the intensity of the scattered light is considered as a function of the position of the visualized object (an absorbing half-plane immersed in a plane layer of the scattering medium). The opportunities for enhancing the quality of the images formed in this way are also discussed.