Effects of misalignments in the optical vortex transformation performed by holograms with embedded phase singularity

Spatial characteristics of diffracted beams produced by a "fork" hologram from an incident circular Laguerre-Gaussian beam whose axis differ from the hologram optical axis are studied theoretically. General analytical representations for the complex amplitude distribution of a diffracted beam are derived in terms of superposition of Kummer beams or hypergeometric-Gaussian beams. The diffracted beam structure is determined by combination of the "proper" topological charge m of the incident vortex beam and the topological charge l of the singularity "imparted" by the hologram. Evolution of the diffracted beam structure is studied in detail for several combinations of m and l and for various incident beam displacements with respect to the optical axis of the hologram. Variations of the intensity and phase distribution due to the incident beam misalignment are investigated and possible applications for the purposeful optical-vortex beam generation and optical measurements are discussed.Comment: 23 pages, 8 figure

The Ploskie Sopki volcanic massif: Geology, petrochemistry, mineralogy, and petrogenesis (Klyuchevskoi Volcanic Cluster, Kamchatka)

This paper is concerned with the geological history and petrology of a major polygenic volcanic edifice dating back to Upper Pleistocene to Holocene time. This long-lived volcanic center is remarkable in that it combines basaltic and trachybasaltic magmas which are found in basaltic andesite and trachybasaltic– trachyandesite series. The inference is that the coexisting parent magmas are genetically independent and are generated at different sources at depth in an upper mantle volume. The associated volcanic rocks have diverse compositions, stemming from a multi-stage spatio–temporal crystallization differentiation of the magmas and mixing of these in intermediate chas

New Tendencies in Employment During the Transition to the Market Economy

The Russian economic reform has shown that in addition to the contradictions inherent in world civilization, in particular between scientific-technological progress and the lowering of unemployment, the nature of labor, working conditions and the remuneration of labor, there are purely Russian problems connected with the high level of the population's labor activity; the low living standard and low effectiveness of labor; insufficient territorial-branch mobility of the work force; a system for training and retraining the work force that does not always correspond to market conditions; and the insufficient development of the labor market's infrastructure.