Structure of an edge-dislocation wave originating in plane-wave diffraction by a half-plane

A new treatment of the well-known Sommerfeld solution of the problem of plane-wave diffraction from a perfectly conducting half-plane is reported. We show, in both theory and experiment, that the diffraction field (E-polarization) can be represented as a superposition of real physically existing waves, in contrast to geometrical and boundary waves postulated in Sommerfeld's representation. Our representation includes two pairs of wave components: one pair propagates along the direction of the incident wave, and the other in a mirror-reflected direction. Each wave pair consists of a plane-wave component with an amplitude half that of the incident wave and a nearly plane-wave component with an infinitely extended edge dislocation. On the basis of the proposed interpretation, all features of the half-plane diffraction are explained.     

Optical vortex symmetry breakdown and decomposition of the orbital angular momentum of light beams

Two forms of the transverse energy circulation within plane-polarized paraxial light beams are specified: one inherent in wave-front singularities (optical vortices) and the other peculiar to astigmatism and asymmetry of beams with a smooth wave front. As quantitative measures of these energy flow components, the concepts of vortex and asymmetry parts of a beam's orbital angular momentum are introduced and their definitions are proposed on the basis of beam intensity moments. The properties and physical meaning of these concepts are analyzed, and their use for the study of transformations of optical vortices is demonstrated.     

Influence of four types of data on diagnostic conceptualization in psychological testing.

"… judges were called upon to specify certain behaviors, characteristics and interests of a subject (a) on the basis of biographical facts alone and then (b) on the basis of either observation of roleplaying situations, interpretation of a Rorschach protocol, or study of a battery of objective and projective tests… . The judges… did not differ significantly in over-all accuracy regardless of the type of information on which their judgments were based… [and] roleplaying situations, and… the subject's Rorschach protocol… [permitted of] no greater accuracy… than had been achieved by study of biographical facts alone." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Screw Dislocations in Light Wavefronts

Abstract

We discuss screw dislocations of a phase surface as the one type of wavefront of a monochromatic wave. The simple method for construction of the optical wavefronts with an isolated screw dislocation is reported. Laser beams with the dislocations of different orders were experimentally achieved by using diffraction on computer-synthesized gratings.     

Phase reconstruction for speckle fields of light-induced scattering in a LiNbO<Subscript>3</Subscript>:Fe crystal

Reconstructing the phase distribution of scalar speckle fields arising under light-induced scattering in a photorefractive LiNbO₃:Fe crystal is considered. A phase distribution reconstruction method based on simultaneous processing of two interferograms obtained for orthogonal planes of converging reference and signal beams is proposed. The method is more advantageous than single-interferogram methods for analyzing interferograms in the frequency domain because it enables to reduce the number of false-detected optical vortices and increase the SNR in phase reconstruction.