Characterization of the Vortex Beam by Fermat’s Spiral

In this paper, we characterize the helical beam structure through an analysis of the spiral character of the phase distribution inside a light beam. In particular, we show that a line connected with the 2π phase jump in the Laguerre–Gauss beam can be described by a Fermat’s spiral. We propose a numerical fitting method to determine the parameters of a spiral equation for the phase distribution of the helical beam. Next, we extend the procedure to a vortex beam created by the spiral phase plate and apply it to experimental phase maps, which allows us to recover the phase shift introduced into the object beam in the optical vortex scanning microscope.

Качественный анализ вин и виноматериалов методами поляризованно-люминесцентной голографии на основе использования их оптических поляризационных спектров

The article describes the qualitative analysis of wines and wine products using polarization-luminescent holography methods. Identification and classification of wines is carried out on the basis of combined processing of various types of polarization spectra of multiplex reflective luminescent holograms of Denisyuk, obtained from the analyzed samples of the wine products (specific brands of wine). The following types of optical spectra of dynamic holograms were selected for analysis: 1) spectral intensity distribution of polarized luminescence (parameter-I); 2) the spectral distribution of the degree of anisotropy of luminescence (parameter-r) and - the ellipticity coefficient (Ce parameter) of the luminescence of the reconstructed virtual image of an object (object beam). An experimental study has been performed of the polarization properties of a reflective hologram Denisyuk, obtained in a luminescent photoanisotropic-gyrotropic material using a linearly polarized coherent light source. The dependence of the polarization state of the reconstructed image on the polarization of the recovering beam (polarization-holographic memory) is observed.An experiment is described on the investigation of samples, conducted to verify the possibility of using polarization spectra for identification of wine. Not individual fragments of the spectra are processed, as when using scalar spectroscopy methods and vector spectra as a whole, which increases the information content and reliability of the analysis. The results presented in the article can serve as the basis for creating guidelines, using spectral-holographic “portrait” of specific brands of wine, according to the set of characteristic features. This will allow revealing the authenticity of wine products, including such properties as variety composition of the annual harvest.

Photoconductive and nonlinear optical properties of composites based on metallophthalocyanines

The photoconductive, photorefractive and nonlinear optical properties of composites from polyvinylcarbazole or aromatic polyimide containing supramolecular ensembles of (tetra-15-crown-5) - phthalocyaninato gallium, indium, - phthalocyaninateacetato yttrium, - phthalocyaninato ruthenium with axially coordinated pyrazine molecules were investigated at 633, 1030 and 1064nmusing continuous and pulsed lasers. Supramolecular ensembles (SE) were prepared through dissolution of molecular metallophthalocyanines in tetrachloroethane (TCE) and subsequent treatment via three cycles of heating to 90∘C and slow cooling to room temperature. The zscan method in femtosecond and nanosecond regimeswas used for measuring nonlinear optical properties phthalocyaninato indium and yttrium in TCE solutions and polymer films. It was established that effect of heavy metallic atom is basic factor which determines the quantum yield, photorefractive amplification of laser object beam, dielectric susceptibility of third order and nonlinear optical properties of metallophthalocyanines.

Novel Method of Digital Holographic Profilometry

The 3D shape measurement has been one of research hotspots in the field of Mechanical measurement. But general optical 3D shape measurement techniques can only measure the continuous object through the phase unwrapping. It’s very difficult to unwrap the phase of the discontinuous object. To solve this problem, a novel digital holographic interferometry used for measuring the 3D shape is proposed in this paper. In this method, holographic interferograms are generated by object beam and reference beam at different incident angles. Height information of every point at the object surface is extracted independently without the phase unwrapping, thus it can measure the discontinuous object. The simulation and initial experiment results suggest that the method is completely feasible and low-cost, so it has great potential to apply in the industrial production.

Binary Intensity Modulation and Hybrid Ternary Modulation Applied to Multiplexing Objects Using Holographic Data Storage on a PVA/AA Photopolymer

Holographic data pages were multiplexed in a polyvinyl alcohol/acrylamide photopolymer and a liquid crystal device was used to modify the object beam and store objects in the material. A peristrophic multiplexing method was used to store a large number of objects in the same spot of the material. The objects were stored using two different modulations: binary intensity modulation and hybrid ternary modulation. Moreover, the bit error rate (BER) of the images was calculated in order to compare which modulation is most appropriate to be used for holographic data storage.

Multi-Angle Digital Holographic Profilometry for Precision Measurements

A novel digital holographic interferometry used for measuring the 3D shape is proposed. The theory analysis and simulation of multi-angle interferometry are described. General holographic interferometry are not able to measure the discontinuous object because of the phase unwrapping. However, in this method, holographic interferograms are generated by object beam and reference beam with different incident angles. Height information of every point at the object surface is extracted independently without the phase unwrapping. The results of simulation demonstrate that this method can be used for measuring the complicated and discontinuous object. It will be useful for the measuring the large and complex discontinuous surfaces often exist in mechanical machining.