Computer Optics

181-186

Authors: R.V. Skidanov, S.V. Ganchevskaya

We proposed an algorithm for calculating the DOE forming vortex beams with a preset distribution of minima and maxima. We reviewed several versions of this algorithm. We presented the calculation of some configurations of traps to capture transparent and non-transparent micro-objects.

211-217

Authors: S.V. Karpeev, S.N. Khonina, S.I. Kharitonov

A dispersive element in the form of the diffraction grating on a convex mirror surface is investigated. The groove profile of the grating is measured and the intensity distribution between the diffraction orders is calculated as a function of wavelength for the visible spectrum. Optomechanical elements for the required alignments of the spectrometer elements are designed and fabricated. Adjustment of a prototype optical scheme is implemented and point images for three monochromatic incident wavelengths are obtained. The energy distribution between the diffraction orders and the intensity maxima positions are in agreement with the simulation results.

370-375

Authors: P.A. Semenov, S.D. Pol’skikh

Phase-locking system based on the Gerchberg-Saxton algorithm is discussed. A global optimization strategy for retrieving phase information is proposed. The system reduction block-structure method is considered. The system is simulated numerically for different configurations of phased channels.

420-428

Authors: O.V. Mandrikova, E.A. Zhizhikina

This paper describes a method developed by the authors for estimating the state of the geomagnetic field. The method is based on the combination of wavelet transform with radial basis neural networks. The method includes decomposing of recorded geomagnetic field variations on different scale components, estimating their disturbance degree and forming conclusion about the state of the field. For approbation of the method, we used geomagnetic data from the “Paratunka” station (Paratunka, Kamchatka region, data registration is carried out by IKIR FEB RAS). The analysis of the spectral-temporal characteristics of geomagnetic field variations during periods of moderate and strong magnetic storms was performed. Weak perturbations were detected in the geomagnetic field before the storms. Obtained results confirmed the effectiveness of the proposed method.

529-535

Authors: G.I. Greisukh, E.G. Ezhov, S.V. Kazin, S.A. Stepanov

The chromatic correction of the optical systems consisting of the elements manufactured by compression molding, are investigated. The discovered advantages are demonstrated.

592-599

Authors: R.V. Eruslanov, M.N. Orehova, V.N. Dubrovin

This article presents the method of solving the problem of segmentation of the retroperitoneal space organs from the tomographic images; the method bases on the level set function. The method of image pre-processing is based on the nonlinear anisotropic diffusion filter which smooths the image while maintaining the edges between the segments. The segmentation algorithm of tomographic image based on the level set function are synthesized.

635-643

Authors: I.M. Sizova

A method for the approximation of encircled energy in a definite solid angle in the Fraunhofer zone by the simulation of optical transfer function derivative is proposed. The selection of free model parameters allow one to obtain true expansion of encircled energy in the origin of the angle coordinate and at infinity, and good approximation in intermediate domain.

728-737

Authors: A.Kh. Sultanov, I.L. Vinogradova, I.K. Meshkov, A.V. Andrianova, G.I. Abdrakhmanova, A.A. Ishmiyarov, L.Z. Yantilina

It’s proposed to connect radio antenna array in Radio-over-Fiber light guide line through the special optical device, which provides splitting the optical signals in accordance with defined frequency bandwidths. The field calculation inside the device working body is done.

765-771

Authors: V.V. Kotlyar, A.A. Kovalev, M.A. Volynov

We have considered circularly polarized vectorial Hankel beams. These beams are a generalization of the spherical wave with embedded optical vortex. Explicit analytical expressions have been derived for all six components of the electric and magnetic vectors of the electromagnetic field. These expressions are an exact solution of Maxwell's equations. We have shown the difference in free space propagation for Hankel beams with left and right circular polarization. For the far field, we also obtained expressions for the components of the Umov-Poynting vector and angular momentum

781-792

Authors: V.V. Kotlyar, A.A. Kovalev, A.P. Porfirev

It It is shown both theoretically and experimentally that if a cylindrical lens is placed into a laser beam, having an optical vortex with integer topological charge n and on-axis intensity null, then at the double focal distance behind the lens, the n-fold degenerate intensity null is split into n isolated intensity nulls. These intensity nulls lie on a straight line in the transverse plane at an angle of + 45 or – 45 degrees to the axis of the cylindrical lens, depending on the vortex helicity direction (i.e. sign of the topological charge). Experiments show that such a method can be used to determine higher-order topological charges up to n = 100.

802-809

Authors: D.S. Lushnikov, A.Y. Zherdev, V.V. Markin, S.B. Odinokov, A.V. Smirnov

In this paper, dependencies of the angular and spectral selectivity on the incidence angle of the reference beam in a scheme for obtaining reflection and transmission holograms are obtained and analyzed. It is shown that for obtaining color holographic stereograms a scheme for obtaining transmission holograms is more suitable. While the angular selectivity of reflection and transmission color holograms is the same, the spectral selectivity of the reflection hologram is much higher at all wavelengths of recording. A method and equipment for one-step digital recording of color full-parallax holographic stereograms with rasterless image are developed. Samples of color fullparallax security holographic stereograms with a “flip-flop” effect in the image were obtained. The quality of the reconstructed image verifies high spectral selectivity for this type of holograms.

818-829

Authors: A.G. Poleshchuk, V.P. Korolkov, R.K. Nasyrov, V.N. Khomutov, A.S. Konchenko

Development of dedicated methods for nondestructive testing of microstructured optical elements is a prerequisite for the wide-scale manufacturing of diffractive, micro-optical and conformal elements. A variety of approaches to the characterization of diverse types of microstructured optical elements were developed at the laboratory of Diffractive Optics at IAE SB RAS. These methods are intended to test wavefront errors, etch depth and diffraction efficiency during and after the manufacturing of elements with binary and multi-level surface profile. The review of the developed techniques and measuring circuits given in the work takes into account specific features of the elements' parameters and application areas. Testing results for the manufactured elements are discussed.

837-843

Authors: N.A. Ivliev, V.A. Kolpakov, S.V. Krichevskiy

We present a method for determining the concentration of organic contaminants on the silica surface by using lateral force maps and surface topology images obtained with scanning probe microscopy. In this study, we optimized the scanning frequency to increase the contrast of images and facilitate interpretation of the data btained. We also proved experimentally that the sensitivity of the method reaches 10−11 g/cm2 .

850-854

Authors: D.S. Mikhailova

In a number of situations, the resolution of modern spectrometers may be not high enough. This communication describes the use of an auxiliary interferometer together with a diffraction spectrometer, thus enabling its resolution and sensitivity to be enhanced during spectroscopy of adsorbed molecular layers. In this way, the industrial device is turned into a combined diffractioninterference monochromator. Numerical calculations and experiments show that the resolution of the combined diffraction spectrometer can be enhanced by an order of magnitude. In addition, the described device is a tunable multi-beam interferometer, allowing scanning through the spectrum. Scanning is done by turning the multi-beam interferometer. The article provides experimental data on adjusting the interferometer by tilting it with respect to incident radiation. Provision is made for the adjustment of the device by using a piezo plate. The increased sensitivity of the combined device allows it to be used as a spectrum analyzer of adsorbed substances. The design of the attachment provides an easy-to-install fitting for the input of the substance under test.

863-870

Authors: M.A. Zavyalova

An experimental laser system for studying the processes of micro– and nanostructure direct formation in a silica glass by picosecond laser pulses is described. A method of ablation monitoring based on the Shack-Hartmann wavefront sensor is proposed. Ablation craters on the surface of the silica glass varying in depth from 23 ± 4 to 144 ± 18 nm with good edge quality with the power density varying from 0.57 × 1012 to 31 × 1012 W/cm2, respectively, are synthesized. Higher-intensity modes of laser processing lead to the formation of cracks and chips on the surface of the material, with lower-intensity processing leading to the appearance of melting edges. The obtained structures are characterized using an atomic force microscope. The ablation rate of the silica glass is established.

878-886

Authors: V.A. Fursov

A problem of the restoration of defocused images is considered. For this purpose, we construct an FIR-filter by identifying the model from a special class of parameters with use of test images. The model of impulse response is defined in a class of univariate functions, which approximate the required frequency response in the radial direction. Samples of the twodimensional impulse response are defined by discretization and the subsequent sample normalization. The approximation function class is defined so as to amplify low and suppress high spectrum frequencies. Important advantages of the method are high-quality image restoration and fast identification of filter's model due to the fact that the approximating function is determined by a small number of unknown parameters. In this article realization examples are given. These examples show the possibility of achieving the higher-quality restoration in comparison with the Wiener filter from the open-source image processing library OpenCV.

895-903

Authors: A.V. Umnov, A.S. Krylov

In this paper we suggest an algorithm for ringing suppression based on a sparse representation method. As one of its steps, the suggested method includes image deblurring based on the Wiener-Hunt deconvolution algorithm. The ringing suppression algorithm uses the signals' mutual coherence and sparsities analysis when dealing with the ringing effect based on the sparse representation method. We also analyze the mutual coherence and sparsities for blurred images and images with white Gaussian noise.

911-918

Authors: A.V. Akimov , A.A. Sirota

The paper describes mathematical models and algorithms of warping grid functions with discrete parameters. For images, three warping models, applied to the generation of extra training data to build face recognition algorithms, are examined: the one based on harmonic functions, the one based on offsetting user-specified control point coordinates, and the one based on the computation of the optical flow between entropy-filtered images. For the training sets, both initial and those synthetically generated using the above three models, learning of face detection algorithms based on the ViolaJones framework was performed and corresponding detection rates were compared. It is shown that this approach is applicable for synthetic data generation when training image recognition algorithms for recognition of objects characterized by inherent structure.

929-938

Authors: N.S. Vorobiova, V.V. Sergeyev, A.V.Chernov

The paper deals with the development of information technology for early crop identification in the region of interest by using satellite images. With the early identification being performed in the first half of the growing season, it is characterized by the lack of ground-based and space-based data to configure recognition algorithms. The proposed technology allows one to generate a training dataset by using information from the past years and then use it for crop recognition for the current year. The technology consists of two stages. At the first stage, models of time series, crops and agroseasons are built using data from the past years. At the second stage, data of the current year are processed. First, a suitable model of agro-season, which is close to the development of crops in the current year, is selected by using a tiny set of control fields with known crops. Next, a training dataset is generated based on the characteristics of the agro-season model and the recognition of crops in the current season is performed. The paper assesses the quality of recognition offered by the proposed information technology and the possibility of its application in a particular region. Data collected for the years 2011 -2015 in the Samara Region are used for the experimental research.

947-957

Authors: A.A. Morozov, O.S. Sushkova

Object-oriented logical means for a real-time analysis of video were developed. The software includes a translator of the Actor Prolog object-oriented logic language to Java, an open source Java library that contains built-in classes of Actor Prolog, and a programming environment of the Actor Prolog language. An example of using the software for intelligent video monitoring of abnormal behavior in people is considered. Object-oriented means of the Actor Prolog language make it possible to divide a logic program into several parallel processes corresponding to various stages of the video processing. The translation of logic programs to Java provides reliability, portability, and openness of the intelligent video surveillance programs.

968-971

Authors: R.V. Skidanov, V.A. Blank

We considered the feasibility of using a dual-range diffraction grating on the convex mirror in an imaging hyperspectrometer based on the Offner scheme. We conducted modeling in Zemax software. It is shown that the use of a dual-range grating allows one to use the hyperspectrometer based on the Offner scheme in two spectral ranges: the visible and mid-infrared.

605-624

Authors: V.A. Soifer, О. Korotkova, S.N. Khonina, Е.А. Shchepakina

The review covers publications concerned with propagation of laser beams through turbulent media described by the Kolmogorov theory and generalizations thereof to describe signal transmission in optical communications and detection systems. In this case, the turbulent medium is interpreted as an optical channel with random parameters. Various optical signals considered include partially coherent beams, non-uniformly polarized vector beams, as well as specifically configured spatial laser beams. Special attention is given to vortex laser beams. The latter are shown to have a number of remarkable properties that give them an advantage over conventional Gaussian beams.

629-634

Authors: E.S. Kozlova, V.V. Kotlyar

In this work a solitary surface plasmon-polariton was obtained by using a frequency-dependent finite difference time-domain method for the TM- and radially polarized light at 532 nm, which was propagated through silver nano-elements (a nano-strip and a nano-ring), placed in an aqueous medium. The device's height and width were equal to 20 nm and 215 nm respectively. The intensity of surface plasmon-polariton was four times higher than that of the incident radiation. The full width at half maximum of the nanojet was 138 nm and 158 nm for the case of using a nano-strip and a nano-ring respectively.The results can be used to design devices that allow capturing and moving particles in water or other biofluids.

642-648

Authors: V.V. Kotlyar, A.G. Nalimov

Using simplified Richards-Wolf formulas we show that laser light with azimuthal polarization and singular phase can produce a smaller focal spot than that from a laser beam with radial polarization, other conditions remaining the same. It is numerically shown that when focusing an azimuthally polarized laser beam with phase singularity using a zone plate a 1.3 times smaller focal spot can be attained than when an aplanatic lens is used. A spiral phase plate can be replaced with a phase step with a π-phase shift. In this case the subwavelength focal spot from a laser beam with azimuthal polarization, which is formed near the zone plate surface, loses circular symmetry, while becoming smaller and acquiring an elliptical form with radiuses of 0.273λ and 0.314λ (NA = 1).

654-658

Authors: D.A. Fadeev

Methods of numerical simulation of two-dimensional short laser pulse nonlinear dynamics are discussed. In this work parallel processing methods for modern CPU (central processing units) architectures supporting non-uniform memory access are considered. The method of adaptive mesh subdivision is proposed to reduce non-uniform load of each CPU during processing of nonlinearity. The results of the tests performed on the Intel Nehalem based a workstation with eight cores are presented.

668-673

Authors: P. Verma, V.S. Pavelyev, B.O. Volodkin, K.N. Tukmakov, A.S. Reshetnikov, T.V. Andreeva, S.A. Fomchenkov, S.N. Khonina

This paper reports the design and fabrication of a 2-degree-of-freedom (DOF) decoupled vibratory gyroscope based on a silicon-on-insulator (SOI) MEMS process. The 2-DOF capacitive comb structure is deliberately designed to have a decoupled drive and sense mode oscillation to prevent the unstable operation due to mechanical coupling, resulting in a low zero rate out-put drift. It is well known that the closer are the drive and sense resonances, the higher is the angular rate resolution of the gyroscope. Generally, this is achieved by using symmetric suspensions, but it results in a reduced bandwidth. The proposed design has been configured to achieve a bandwidth of about 150 Hz, while ensuring the decoupled operation of the drive and sense modes. An analytical method has been employed to study the steady state response of the 2-DOF structure. FEM analysis has been carried out in CoventorWare® MEMS Design software and the simulation results show that the drive resonance occurs at 21.48 kHz and sense resonance at 21.63 kHz, which are in close agreement with the theoretical results. The structure is designed with a 15 µm thick device layer. Fabrication of the design is proposed using a two mask process based on Deep reactive-ion etching (DRIE) and sacrificial wet release etching on a SOI wafer. DRIE etching with an aspect ratio of 1:5 has been successfully carried out as desired and the results have been presented.

679-684

Authors: S.P. Murzin, R. Bielak, G. Liedl

Based on the use of methods for solving the inverse problem of heat conduction, we developed an algorithm for calculating the power density distribution of the laser beam to create a desired thermal effect on technological objects. It was shown that the redistribution of power density of moving distributed surface heat sources can adjust the temperature distribution in the treated zone. The results of thermal processes calculation show the ability of the developed algorithm to create a more uniform temperature field across the width of the heat affected zone. Equalization of maximum temperature values is achieved in the center and on the periphery of the heat affected zone with an increase in the width of the regions, where required temperature is reached. The application of diffractive optical elements gives an opportunity to obtain the required properties of treated materials in the heat affected zone. The research performed has enabled parameters of the temperature field in chrome-nickel-molybdenum steel to be adjusted for laser heat treatment. In addition to achieving uniform temperature conditions across the width of the heat affected zone, the proposed approach allows the increase of the width of the isotherms of the temperature fields; this provides an opportunity to process a larger area per unit time at the same laser beam power.

689-712

Authors: M.V. Gashnikov, N.I. Glumov, A.V. Kuznetsov, V.A. Mitekin, V.V. Myasnikov, V.V. Sergeev

In this paper, we consider methods for hyperspectral image processing, required in systems of image formation, storage, and transmission and aimed at solving problems of data compression and protection. A modification of the digital image compression method based on a hierarchical grid interpolation is proposed. Methods of active (on the basis of digital watermarking) and passive (on the basis of artificial image distortion detection) data protection against unauthorized dissemination are developed and investigated.

721-728

Authors: V.A. Fursov, Ye.V. Goshin, A.P. Kotov

In this paper a procedure of building a digital terrain model (DTM) from the satellite images is researched. The procedure is based on the authors' previously developed algorithms of fast image matching for building disparity maps implemented on GPUs (Graphics Processing Units). In this paper we propose a computational procedure for constructing a DTM from the satellite stereo images. Experimental studies have shown that while this procedure constructs a DTM that may be less accurate than the one achieved with the use of the ENVI software, it offers a significantly shorter time of processing.

740-745

Authors: V.B. Nemirovskiy, A.K. Stoyanov, D.S. Goremykina

In this paper problems of featureless face recognition are considered. The recognition is based on clustering the proximity measures between the distributions of brightness clusters cardinality for segmented images. As a proximity measure three types of distances are used in this work: the Euclidean, cosine and Kullback-Leibler distances. Image segmentation and proximity measure clustering are carried out by means of a software model of the recurrent neural network. Results of the experimental studies of the proposed approach are presented.

752-758

Authors: M.S. Boori, K. Choudhary, A.V. Kupriyanov

City vulnerability is an assessment of priorities for implementation in a city. Thus, it is imperative to determine vulnerable regions in the city to identify priority areas that may require immediate intervention. Several methods used for national, international and local level vulnerability assessment are based on remote sensing and GIS technology. This paper aims to determine the vulnerability of Hyderabad city using a geospatial based vulnerability index for sustainable development of the city. We use an urbanization and vulnerability concept for the development of city policy measures. We assessed the city vulnerability using a conceptual diagram composed of exposure, sensitivity and adaptive capacity. For Exposure, we considered the elevation (contour), watershed, waterway, roads, railways and airport thematic layers. For Sensitivity, the built-up area, industry, manages (?) system such as farmland and land use/cover map from GIS data were used. To examine the adaptive capacity, we addressed the natural vegetation layer, economic points and infrastructure. Results show that the center and northern part of the city are highly and extremely vulnerable due to industry and high socio-economic activities when compared with the southern part of the city. We divided the whole city into 5 types of vulnerability: Resilient 2.24 %, at risk 13.20 %, vulnerable 46.15 %, highly vulnerable 7.26 % and extremely vulnerable 31.15 % , in terms of the city area percentage. The vegetation area (50.51 %) has the maximum vulnerable area and the vulnerable class covers the maximum area (46.15 %) of the city. All this information is very indispensable and can be used to address management issues, such as resource prioritization and optimization.

431-438

Authors: D.A. Kozlov, E.S. Kozlova, V.V Kotlyar

In this paper a research on conditions for resonance excitation in a homogeneous dielectric cylinder with square cross-section is conducted using a FDTD-method. It is shown that in a cylinder with square cross-section resonant modes similar to whispering gallery modes can be excited, which allows one to reduce the transverse dimensions of the focal spot. FDTD method demonstrates an acceptable accuracy of the resonant mode detection. A similar result is obtained for a cube on a dielectric substrate: it is possible to achieve the reduction of the transverse dimensions of the focal spot by changing the corresponding cube size.

451-457

Authors: V.V. Kotlyar, A.G. Nalimov, M.V. Kotlyar

We propose a new version of the metalens, namely, a polarization microlens (PML) that focuses the linearly polarized laser light in a subwavelength circular spot. The PML consists of a set of binary subwavelength gratings, which are laid out in a parquet manner within the rings of a Fresnel zone plate. A phase shift of π, which the zone plate should introduce into the light field in passing the zone boundary, is implemented in the PML under study using two diffraction gratings adjacent to the zone boundary, which form oppositely polarized transmitted beams. It is shown that the PML relief depth can be reduced using a high refractive index material. For amorphous silicon, the PML relief depth can vary from 50 nm to 120 nm. In this case, a circular focal spot having a diameter smaller than the diffraction limit is formed at distances to the PML ranging from 200 nm to 1300 nm. The minimum focal spot diameter is 0.372 of a wavelength.

467-474

Authors: K.V. Andreeva, M.A. Moiseev, S.V. Kravchenko, L.L. Doskolovich

A novel method for the design of total internal reflection based (TIR) optical elements generating complex two-dimensional narrow-angle light distributions is presented. The method consists of two parts: computation of a piecewise smooth solution and its subsequent approximation by a spline surface. Examples of TIR optical elements designed using the proposed approach are discussed. The simulation results demonstrate high performance of the proposed method: the luminous efficacy of the optical elements is 91.8% and the relative root-mean-square error is less than 8.6%.

482-488

Authors: V.P. Korolkov, A.S. Konchenko, V.V. Cherkashin, N.G. Mironnikov

A process of manufacturing conformal correctors for solid state YAG:Nd3+ lasers is discussed. It is proposed that a maskless lithography method should be used for fabricating a photoresist film with a desired thickness profile as an alternative to the proximity lithography based on half-tone masks. The use of a specular spectral scatterometry method for the testing of the conformal corrector shape at an early stage of photoresist profile formation is reported. A combination of these two methods makes the corrector manufacturing process significantly cheaper and faster.

501-507

Authors: S. A. Shoydin

For the case of 3D phase holograms, the impact of the form factor on the hologram diffraction efficiency is shown. The form factor concept is introduced by analogy with the classical definition, which is used for calculating the averaged interaction of complex-shaped objects. In the present context, the form factor concept is used for determining the average diffraction efficiency of the holograms formed with the help of beams distributed non-uniformly over the hologram field. It is shown that after calculating the corrections, they can be used in the same way as coefficients in the classical formulas of the diffraction efficiency. The impact of such a form factor only comes into play when there are two factor present at the same time, i. e. non-linearity of photoresponse and non-uniformity of the light beam distribution over the hologram field.

516-525

Authors: N.A. Lomov, L.M. Mestetskiy

A "width of a shape" concept considered in relation to variable-width objects is used as the integral shape descriptor for image recognition tasks. The approach to the definition of this concept is based on covering the figure of interest with certain-size disks. A function that defines the area of disk cover against the disk size is used as a shape descriptor. An analytical method for calculating the area of disk cover for polygonal figures is proposed. The possibility to approximate by polygonal figures binary raster images and objects with non-linear boundaries makes the approach universal. The proposed method is based on the medial representation of objects as a skeleton and a radial function. The method provides high accuracy and computational efficiency. The efficiency of the proposed shape descriptor is illustrated by the example of its application to the digital font recognition problem.

535-542

Authors: A.Y. Denisova, V.V. Sergeye

In the article we offer a novel approach to calculating multichannel image histograms using hierarchical data structures. The proposed methods result in a histogram-tree which has many advantages over existing data structures traditionally used for multidimensional histograms. The suggested data structure requires a significantly smaller memory space for storage in comparison with a histogram that is presented as a frequency table for all possible brightness values (histogramhypercube). The histogram-tree provides a dramatic decrease in speed in comparison with the list of unique brightness values and their frequencies (histogram-list). Moreover, the histogram-tree allows one to approximate the probabilities of brightness values which are not presented in the analyzed image in contrast with the histogram-list. The possibility of histogram approximation is very important for practical applications. Such approximation for histogram-tree is constructed by means of tree reduction. Nodes with frequencies lower than a given threshold are removed from the histogram-tree. The reduced histogramtree benefits from the decrease of the required memory space while maintaining the accuracy of the original probability density distribution representation. We propose two algorithms for constructing a histogram-tree. The “depth” algorithm operates with image pixels sequentially. For each pixel it constructs appropriate branches and nodes until the maximum depth of the tree is achieved. This algorithm has a recursive realization and is more time efficient than the other one. The “across” algorithm performs a multiple scan of the image, each time filling just one tree level. This algorithm allows tne to operate with images with a larger number of channels than the “depth” algorithm because it is more memory efficient in the runtime when approximating a histogram. Both algorithms build the histogram-tree significantly faster when compared with the construction of the histogram-list. The theoretical estimates and experimental results described in the article demonstrate that computing histogram of multichannel images using histogram-tree has many advantages over the histogram-hypercube and histogram-list.

552-559

Authors: S.A. Borminsky, A.V. Solntseva, B.V. Skvortsov

The article describes a method for optoelectronic control of liquid volume in a tank. Measurements can be performed remotely without tank calibration. The method is based on the fact that there is a near-wall region where the liquid surface has a higher reflectivity. This region occurs due to surface tension or minor ripples. With this method, first, an image of liquid surface is taken with a photo-camera. Then, a near-wall liquid-air boundary is identified in the image before calculating the current area of the liquid surface. When the tank is filled for the first time, the device records the liquid area for every level. A calibration table is automatically created without applying additional tools. To avoid the error caused by inaccurate photo-camera positioning, a special mathematical model is devised. It uses reference marks made on tank walls horizontally. An algorithm for recognition of liquid boundaries in the image is developed. Measurements of the liquid volume conducted using a laboratory prototype have shown the reduced error to be within 0.5%, provided that the digital photo-camera is not rigidly fixed.

572-582

Authors: D.V. Mikhaylov, A.P. Kozlov, G.M. Emelyanov

In this paper we look at two interrelated problems of extracting knowledge units from a set of subject-oriented texts (the so-called corpus) and selecting texts to the corpus by analyzing the relevance to the initial phrase. The main practical goal here is finding the most rational variant to express the knowledge fragment in a given natural language for further reflection in the thesaurus and ontology of a subject area. The problems are of importance when constructing systems for processing, analysis, estimation and understanding of information. In this paper the text relevance to the initial phrase in terms of the described fragment of actual knowledge (including forms of its expression in a given natural language) is defined by the total numerical estimate of the coupling strength of words from the initial phrase jointly occurring in phrases of the text under analysis. The paper considers known variants of such estimation procedures and their application for the search of distinct components which reflect the initial phrase in the texts selected to the topical text corpus. These components correspond to words and their combinations. In comparison with the search of such components on a syntactically marked text corpus, the method for text selection offered in this paper enables a 15-times reduction (on average) in the output of phrases which are irrelevant to the initial one in terms of either the described knowledge fragment or its expression forms in a given natural language.

588-593

Authors: S.A. Degtyarev

In this work, using a finite element method implemented we simulate in the Comsol software focusing a TE-polarized Gaussian beam by 3D dielectric conical microaxicon tapers with smaller-than-30-degrees vertex angles. The simulation results have shown that, as is the case with the 2D axicons, with minor changes in a vertex angle, the 3D axicon can alternatively show either focusing or defocusing properties. However, the angle intervals in which the 2D and 3D axicons show focusing or defocusing properties are different.

305-311

Authors: A.A. Kovalev, V.V. Kotlyar, A.P. Porfirev

Transfer of the orbital angular momentum to dielectric microparticles optically trapped using recently discovered asymmetric Laguerre-Gaussian (LG) laser beams is demonstrated. We experimentally show that at a fixed topological charge, increasing beam asymmetry parameter leads to increasing velocity of the polystyrene beads moving along a crescent-shaped path.

322-330

Authors: V.V. Ivakhnik, M.V. Savelyev

Spatial characteristics of the degenerate four-wave radiation converter in a liquid containing nanoparticles were studied using a scheme with concurrent pump waves. The phase matching condition was shown to determine the general form of the spatial spectrum amplitude of the object wave, with the electrostriction phenomenon and Dufour effect shown to cause the emergence of dips in the spatial spectrum amplitude, with the dip positions corresponding to the propagation directions of the pump waves. The relationship between characteristics of the dips and the pump wave parameters were obtained.

338-345

Authors: L.L. Doskolovich, E.S. Andreev, M.A. Moiseev

A new optical surface reconstruction technique in the source-target mapping method is proposed. The technique is based on the representation of the surface as an envelope of a parametric family of paraboloids (ellipsoids). Using such a representation, the calculation of the optical surface is reduced to solving a complete differential equation without regard for the coordinate system. By way of illustration, mirrors that generate uniform intensity distributions in a square region are designed. Simulation of the design examples shows high performance of the proposed technique: it allows us to obtain good-quality intensity distributions even with violation of the integrability condition.

353-359

Authors: S.P. Murzin

We proposed a method of the formation of structures in materials by laser treatment aimed to enhance the performance characteristics of aircraft engine parts. The experimental study was conducted using a high-power gas CO2 laser ROFIN DC 010. Using an optical system comprising a focusing diffractive optical element, the laser beam was focused into a focal line with the maximum power density in its center. Tests on the joint deformation of the coating and substrate were conducted. We also determined the running-in ability of the ANB + NA-67 coating following the cut-in of an opposite element. It was found that the laser treatment of the sublayer enabled the bending angle to be increased while avoiding cracking and delamination of the coating.

370-379

Authors: O.V. Phylonin

We describe methods, algorithms and means of narrow-angle spectral and tomography diagnostics of parameters of plasma flows such as spatial local temperature distribution and concentration for small-size plasma ejectors (engines for orientation in space and thrusters).

388-394

Authors: S.M. Borzov, A.V. Golitsyn, O.I. Potaturkin

Methods for generating a synthesized image with increased depth of field from a sequence of real-time frames received by varying-range focusing using liquid optics are investigated. An algorithm based on constructing a map of ranges by analyzing a contrast pyramid and the weighed pixel-by-pixel summation of the initial images whose coefficients are proportional to the number of same-range pixels in each local neighborhood is developed.

404-409

Authors: R.G. Khafizov, S.A. Okhotnikov, T.V. Yaranceva

Mathematical models of contours of simple- and arbitrary-shape object images affected by geometrical distortions are proposed. It is shown that the contour spectrum is supplemented with additional harmonics depending on the type of the geometrical distortion. Models of contours with a combination of different geometrical distortions are discussed.

416-421

Authors: V. V. Sergeev, R. R. Yuzkiv

A new parametric model for the autocorrelation function of space hyperspectral data has been proposed. A heuristic algorithm for estimating the model parameters has been developed. The proposed model has been demonstrated to provide a good approximation of the observed autocorrelation functions.