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The polarization plane of a diffracted wave in the transmitted diffraction orders is shown by us to be significantly rotated, which is absent in the reflected diffraction orders, for anisotropic Bragg light diffraction on volume phase holographic gratings for significant perturbation amplitudes of the medium refractive index. Periodic changes in the transmission coefficients of diffracted waves with a change in the azimuth of incident light polarization are shown to be due to a significant difference in the Fresnel reflection coefficients at the layer boundaries for the s- and p-components of the incident light. These periodic changes are absent in the reflected diffraction orders. [ABSTRACT FROM AUTHOR]

The diffraction of light by reflective holographic gratings in a layer placed between the coating and the substrate having refractive indices different from the average refractive index of the inserted layer is investigated. Significant differences between the reflection and transmission coefficients of the light diffracted on such a holographic grating with a change in the modulation amplitude of the refractive index of the layer, and the reflection and transmission coefficients of reflection gratings in matched structures are established. It is shown that at a large width of the layer in which the reflective holographic grating is located, there is a significant rotation of the plane of polarization of reflected and transmitted diffracted waves with a change in the modulation amplitude of the layer, caused by Fresnel reflection of light at the layer boundaries. [ABSTRACT FROM AUTHOR]

Dependences of the polarization characteristics of light reflected by various surfaces have been studied. A heterogeneous system was analyzed by the method of partitioning and physicomathematical modeling of the structure, with "effective substrate" or "effective layer" model used. A method for measuring the polarization of reflected radiation has been developed and its polarization characteristics have been studied experimentally. It is shown that for all samples, the azimuth of polarization of reflected light decreases with increasing the angle of radiation incidence. It has been established experimentally that light reflected from the samples under study remains virtually linearly polarized. [ABSTRACT FROM AUTHOR]

Tight-focusing properties of cylindrical vector circular Airy beams [i.e., azimuthally polarized (AP) circular Airy beam and radially polarized (RP) circular Airy beam] passing through a high numerical aperture thin lens are investigated in detail. It is found that a super long subwavelength dark channel with full width at half maximum about 0.49 λ and depth of focus (DOF) about 52 λ can be achieved near the focal region for the case of tight focusing of an AP circular Airy beam, and a super long needle with DOF about 27.5 λ of strong longitudinally polarized field can be obtained near the focal region for the case of tight focusing of a RP circular Airy beam. Furthermore, we report experimental generation of an AP circular Airy. Our results will be useful for atom guiding and trapping, particle acceleration and fluorescent imaging. [ABSTRACT FROM AUTHOR]

Analytic expressions are obtained for the energy flux and density of refracted nonuniform waves produced during total reflection at the boundary between two isotropic media for the general case of elliptically polarized incident light. The average values are determined as functions of the parameters of the adjoining media and the angle of incidence. The cases of linearly and circularly polarized incident waves are examined in detail. An explicit general expression relating the energy fl ux and density of these waves for arbitrarily polarized incident light is obtained. [ABSTRACT FROM AUTHOR]

Analytical expressions are obtained for and used in calculations of the transmittance of thin (on the order of a wavelength) layers under conditions of total reflection at one of the boundaries in the general case of linearly polarized radiation where the oscillation azimuth of the incident wave is not 0 or π/2. The transmittances of this kind of layer for TE ( s-polarization) and TM ( p-polarization) waves are compared. The analytic expressions are used to calculate the dependence of the energy transmittance on layer thickness for a fixed angle of incidence and different oscillation azimuths of a linearly polarized incident wave, as well as for several angles of incidence (including the critical angle) with a fixed oscillation azimuth. [ABSTRACT FROM AUTHOR]

In a recent paper, Leka et al. ( Solar Phys. 260, 83, ) constructed a synthetic vector magnetogram representing a three-dimensional magnetic structure defined only within a fraction of an arcsec in height. They rebinned the magnetogram to simulate conditions of limited spatial resolution and then compared the results of various azimuth disambiguation methods on the resampled data. Methods relying on the physical calculation of potential and/or non-potential magnetic fields failed in nearly the same, extended parts of the field of view and Leka et al. ( Solar Phys. 260, 83, ) attributed these failures to the limited spatial resolution. This study shows that the failure of these methods is not due to the limited spatial resolution but due to the narrowly defined test data. Such narrow magnetic structures are not realistic in the real Sun. Physics-based disambiguation methods, adapted for solar magnetic fields extending to infinity, are not designed to handle such data; hence, they could only fail this test. I demonstrate how an appropriate limited-resolution disambiguation test can be performed by constructing a synthetic vector magnetogram very similar to that of Leka et al. ( Solar Phys. 260, 83, ) but representing a structure defined in the semi-infinite space above the solar photosphere. For this magnetogram I find that even a simple potential-field disambiguation method manages to resolve the ambiguity very successfully, regardless of limited spatial resolution. Therefore, despite the conclusions of Leka et al. ( Solar Phys. 260, 83, ), a proper limited-spatial-resolution test of azimuth disambiguation methods is yet to be performed in order to identify the best ideas and algorithms. [ABSTRACT FROM AUTHOR]

Expressions are obtained for the integral characteristics of single scattering of polarized radiation on particles of arbitrary shape. Polarized radiation is described by Stokes parameters. The two known scattering characteristics are examined-the full scattering cross section and the scattering matrix normalization constant. A dimensionless scattering integral is analyzed that takes into account possible scattering of incident radiation in all directions and determines the two considered integral characteristics. The integral is expressed via the scattering matrix elements and Stokes parameters of incident radiation. In the case of a nonspherical particle, the matrix elements depend on the direction of radiation incident on the particle. In this connection, the total scattering is affected by the structure of the incident beam. The practically important cases of particle illumination by parallel and convergent beams are considered. Expressions are obtained for the integral characteristics, averaged over the directions of incident radiation. Simple relations between the two scattering characteristics under different particle illumination are derived. [ABSTRACT FROM AUTHOR]

The dynamics of the polarization structure of the speckle field of the photo-induced scattering in LiNbO3:Fe (unsteady regime) has been analyzed with the use of the methods of the modified Stokes polarimetry. It has been shown that the creation and annihilation of pairs of circularly polarized points ( C points) in varying singular elliptically polarized fields proceed via two topological scenarios. It has been found that the creation of pairs of C points is preceded by the appearance of a region where the average ellipticity is larger than the values in the neighboring regions. A similar structure holds after the annihilation of C points. [ABSTRACT FROM AUTHOR]

Specific features of manifestation of optical activity in cubic, uniaxial, and biaxial crystals are described. The effect of optical activity on characteristics of transmitted light is considered as a function of the wavelength of incident light, temperature, and the orientation the optical axis. The results of the investigation of crystals of different symmetry classes are reported. [ABSTRACT FROM AUTHOR]