This PDF file contains the front matter associated with SPIE Proceedings Volume 11516, including the Title Page, Copyright information, and Table of Contents.

Modern optical transport network is a highly complex object and introduces a challenge to managing and exchanging of management information in an accurate and recognize manner. Different optical technologies and service delivering rules increase the complexity of the network management activities. This paper analyzes machine-learning techniques of the optical network management with taking into account the knowledge representation based on the object-oriented ontology. Object-oriented ontology can be defined in general as a formal specification of a machine-readable vocabulary which is result of experts analyze. Object-oriented ontology is formulated in the terms of classes or entities and associations between them, to describe knowledge about the contents of the optical transport network management and another related object as quality of transmission, wavelength routing, flexible grid. Object-oriented ontology can be mapped for a machine learning models in the context of general management networks areas as fault management, performance management, configuration management, security management, business process management. Some machine-learning techniques for the optical network test and management are examined. Main entities of optical transport network management and their relations are discussed.

An interference polarizer for forming a radially-polarized zero-order vortex Bessel beam with the wavelength of 1530 nm has been developed. The polarizer contains 33 layers of SiO₂ / Nb₂O₅ evaporated on a glass substrate using the vacuum electron beam method. The measurement of polarizer characteristics showed the ratio of transmittance of radially- and azimuthally-polarized beams to be 80:1 – 90:1 with the angle of incidence equal to 24.5 – 25°. The transmittance of radially-polarized light was not less than 75%. A radially-polarized zero-order vortex Bessel beam of high optical quality was formed with the help of the developed polarizer and a diffractive axicon.

The holographic coding method improves the reliability of storing digital information in memory systems that are subject to external influences that introduce a large number of errors. The method is based on writing to memory instead of the initial data of a digital hologram created in the virtual space by a wave from an input source. The property of the hologram divisibility is used, allowing to recover the recorded data block by its fragment. The achieved level of noise immunity is determined by the size of the hologram. For an 8-bit data block, a 256-bit hologram recording provides recovery of information when 75% of the recorded hologram is lost. The developed decoder corrects the packet of dependent (grouped) errors that distort all bits of the hologram. The number of random independent errors that the decoder corrects can be up to 40% of the recorded information.

This paper describes Optical Virtual Private Network (OVPN). The features and benefits of optical VPN are considered. Consider the OVPN model with a limited network resource on each section of the optical network. The optical network is described using the undirected graph with the set of nodes (correspond to the core optical nodes) and the set of edges (correspond to the link of the optical network connecting adjacent core nodes. Accepting the request for the implementation of OVPN, the service provider must, using the appropriate analysis algorithm, check whether the implementation of the corresponding virtual network is possible. To do this, the algorithm, firstly, selects a path between each pair of OVPN endpoints and, secondly, distributes the available bandwidth on each link in the selected path. If there is not enough bandwidth on the link, the received request for OVPN implementation will be rejected. Various algorithms for implementing the OVPN model: provider channels, individual flows and all flows OVPN are considered. This article discusses a possible approach to solving the problem of the distribution of optical network resources across several OVPN.

Based on the analysis and the urgent tasks of communication systems designed to serve the Industrial Internet through RoF technology, the article explores the significance of a chirped signal on the principles of building segments of RoF systems, and then the principles of generation and conversion of this category of signals.

Following article presents a simple scheme of an acousto-optic channel and an example of the results of modeling lowspeed data transmission in such channel. Previously obtained experimental data on the amplitude-frequency response of the channel were used in the simulation. The simulation results demonstrate the advantage of using a phase receiver for the considered fiber acousto-optic channels compared to direct detection.

The telecommunication systems development based on single-mode and multimode optical fibers is aimed at the rapidly increasing demand for bandwidth not only transport networks, but also intra-site data centers networks, cloud computing, and web servers. The solution to this problem is provided by the signal processing technologies complexity. In this case, the requirements for the receiver complexity can be reduced by using technologies to combat signal distortion due to equalizers together with FEC. There was known that the use of FEC based on permutation decoding in relation to the RS codes provides a significant gain in the data processing speed by the receiver due to the use of a cognitive procedure for searching the generating matrix of the equivalent code. The paper shows that the use of this technology can be successful in solving another important task related to minimizing the timing attacks consequences on the protection confidential information system. This is due to the active development of quantum computers and the problems of post-quantum cryptography that arose on this basis. The essence of leveling the timing attacks risks is to equalize the time spent on processing vectors of redundant BCH or RS codes. The use of permutation decoding fully matches these requirements by replacing the algebraic system of detection and errors correction in the data on the procedure of lexicographic search for the desired result. It is shown that the data processing time when using permutation decoding in conjunction with the cognitive search for the decoding result varies slightly.

In this paper, we present the experimental impulse-radio transmission based on spectral modulation technique aimed at improving the energy efficiency, noise immunity and interception security of high-speed Radio-over-Fiber communication systems. The proposed modulation method is based on frequency-shift keying of three wideband solitonshape pulses with central frequency hopping in the desired frequency range. Mathematical and simulation models for the modulation and symbol coding techniques are provided. The system performance was evaluated through experimental BER measurement on the basis of the ultra-wideband laboratory test bench under the strict regulations of the SCRF spectral emission mask for ultra-wideband systems in Russia. A comparison of the obtained results with the current record of impulse-radio transmission under the SCRF spectral mask showed that the proposed spectral modulation method provides less achievable wireless transmission distance, however gaining into interception security of the link. Nevertheless, the employment of the improved decoding technique can fix this disadvantage. The achieved results demonstrate the application viability of the proposed method in high-speed Radio-over-Fiber communication systems.

We present a novel type of diffractive optical elements - a nonlinear spiral phase plate whose transmission function is described as exp(iφmⁿ). The light field generated by the element has a spiral-shaped intensity and phase distribution, a non-uniform orbital angular momentum (OAM) distribution and spiral-shaped energy flow. Because of the non-linear azimuthal phase variation, the nonlinear spiral phase plates demonstrate angle-dependent distortion resistance properties. We believe that the proposed nonlinear spiral phase plates will be useful for the realization of OAM-Mode Division Multiplexing in optical communication systems as well as in the area of laser manipulation and laser-matter interaction for fabrication of unique chiral metasurfaces that can be used in optical communication systems too.

We performed theoretical and numerical analysis of the focusing properties of a harmonic diffractive lens taking into account the dispersion of the refractive index. It was shown that the harmonic lens is characterized not only by the appearance of additional local foci, but also by a shift of the main foci even for multiple wavelengths, which is associated with the chromatic dispersion of the lens material.

The configurations of rays passing through the axicon are considered, which take into account the presence of both reflected and refracted rays at the boundary of the media. This is important for such values of the angle at the apex of the axicon, when the Fresnel coefficient for the reflected beam is greater than for the refracted one. The passage of rays through the semi-axicon is also considered. An example of quantitative calculation is given, showing that this effect allows forming two divergent conical beams having comparable amplitude at once.

In this paper, several methods of forming a spiral intensity distribution are mentioned and it is noted that they mainly form a spiral in the far diffraction zone. To form a spiral intensity distribution in the near zone, the authors propose to illuminate a helical diffractive microaxicon. The results of numerical simulation within the limits of strict electromagnetic theory visually confirm that a spiral structure is formed. In this case, the formation is more qualitative and more reliable compared to the illumination of the binary spiral axicon.

We investigated subwavelength diffraction optical elements based on ring gratings. We conduct numerical simulation of creation and focusing of the second order radially polarized beam and pulsed radiation passed through the subwavelength diffraction grating. The formation of a shadow focal spot in the immediate vicinity of an optical element, amplification of the longitudinal component of the electric field and the inverse energy flow can arise near the optical axis of the element were shown.

We investigate the generation of closed-packed light rings with a minimum possible diameter using a combination of a light ring distribution generator and a diffractive beam splitter. As a light ring distribution generator, we use the wellknown S-waveplate and generate three different types of ring-shaped laser beams: an azimuthally polarized Gaussian beam, a first-order circularly polarized optical vortex beam, and a first-order linearly polarized optical vortex beam. Our modeling and experimental results show that the azimuthally polarized Gaussian beam is the best solution for splitting in comparison with the other types of beams. These results can be used in applications of high-throughput laser micro- and nanopatterning materials for the fabrication of microlasers by direct laser ablation of a thin film on glass that have great potential in optical communications and sensing applications.

In this paper, we presented a metal-insulator-metal (MIM) waveguide resonator design for filtering white light into individual colours. Six square micro-ring cavities of different sizes are side coupled to MIM bus waveguide. By careful selection of cavity size and distance between bus waveguide and micro-ring cavities, the resonator can selectively couple to intensity maxima of different photonic modes and, as a result, preferentially select any of the primary colours. The spectral characteristics of the resonator are studied by varying the geometric parameters using the finite element method (FEM).

The use of diffractive optical elements (DOEs) opens up new possibilities for controlling the beam shape and the beam intensity distribution for optical telecommunication systems. To increase the beam intensity at peripheries of the laser spot, it is necessary to redistribute the energy portion from the center of the optical element to those areas that are designed to operate under conditions of an exponentially low intensity. This is achieved by using laser beam with a ring distribution of flow intensity. For this case, regularities of the power redistribution of formed laser beams into a line segment, as well as changes in the focus distance and focal length when changing the spatial position of the diffractive optical element are established. The spatial distribution of intensity in the laser spot was measured with the application of CO₂ laser. Results of experimental studies correlate well with the calculated data.

In this paper the polarization state analyzer/generator based on the three-stage polarization controller is developed. The method for determination of input state of polarization based on Muller matrix formalism is proposed. The operation algorithm for regime of generation an arbitrary state of polarization is proposed.

Spherical functions are the angular part of the family of orthogonal solutions of the Laplace equation written in spherical coordinates. They are widely used to study physical phenomena in spatial domains bounded by spherical surfaces and in solving physical problems with spherical symmetry. In this paper, we simulate the formation and propagation of periodical three-dimensional optical fields based on a superposition of spherical functions with specific indices that provide periodic properties of the generated fields. The results showed the dependence of the structure and shape of simple superpositions of optical three-dimensional fields on their indices, in particular on their parity. We show that a superposition of spherical harmonics with indices of equal parity provides explicit periodic properties of the fields along the z axis.

The paper considers photo-induced microrelief formation using Gaussian paraxial vortex laser beams with different polarizations and their characteristics, such as the Poynting vector, gradient force and force density, which are important for assessing the effect of radiation on matter. It is shown that the characteristics, which depend only on the intensity gradient, do not allow to correctly describe dependence of the distribution of optical forces and the formed relief. A model taking into account non-gradient forces is presented. Theoretical and experimental results are compared.

The article presents the research results of the modern radar complexes modernization possibility due to the use of methods and elements of microwave photonics in the devices of signals formation for heterodynes and transmitters of radar stations. Application of high potential active phased antenna array with multichannel spatial processing of received signals, based on the use of microwave photonics technology, will significantly improve the basic tactical and technical characteristics of the radar: range resolution, information value, detection range, noise immunity and power consumption. Realization of the listed advantages is reached by introduction of elements, functional knots and components of active phased antenna array subsystems because of electro-optical modulators and demodulators, sources and receivers of optical radiation, optical signal amplifiers, optical delay lines, fiber-optic, and optical passive elements.

Theoretical analysis of light diffraction on a periodic structure by using exact analytical solutions of the equations and numerical computer calculations has been conducted. The influence of different apodization functions on diffraction curves of reflection and transmission is studied and their comparative analysis is performed. Complete elimination of oscillating sidelobes and a significant suppression of the “tails” of a diffraction reflection curve are achieved for the specific functions of spatial apodization. The maximum values of the reflectivity of the medium with periodic dielectric permittivity are determined. The effects of light absorption in the crystal and moving gratings on the spectral resolution are evaluated. The Fabry-Perot resonator formed by two spatially-distributed “mirrors” is also studied. A significant increase in spectral resolution of filter due to the spatial variation of the refractive index of the medium is shown. It is shown that the high purity crystals are needed to observe the considered effects. Current technologies allow to obtain the glasses with the absorption coefficient α=10^-7 cm^-1 at which the spectral resolution Δλ ≈10^-2 pm could be reached. This is three orders of magnitude narrower than the resolution of existing acoustooptic AO filters with the same crystal thickness. The considered system (a Fabry-Perot spectral filter combining a Bragg grating mirrors with apodization) can significantly increase the resolution of optical diffraction filters. Complete elimination of sidelobes and a significant suppression of the “tails” of a diffraction reflection curve are demonstrated. These results open perspectives to significantly enhance the resolution of the spectrometers, improve the parameters of mobile devices and communication channels. The results are of practical interest and can be used in the development of new diffraction acousto-optic modulators, AO filters and spectrometers.

We introduce solution for polarization correction for propagation constant of a linearly polarized guided modes in a curved optical fiber. We considered a linearly polarized guided modes weakly guiding optical fiber with an arbitrary refractive index profile and constant curvature. Proposed solution is based on well known Gaussian approximation method and stratification method.

In this paper, we considered a model described the propagation of a powerful femtosecond pulse in an optical fiber with maintaining polarization and presented as an example the simulation results for the data of a known experiment and several values of the length of the optical fiber.

An approximate analytical solution for an arbitrary mode of a curved circle weakly guided fiber lightguide with an arbitrary refractive index profile is presented. It is takes into account the influence of the optical fiber coating on the mode parameters. The calculation results are presented for a typical refractive index profile of a multimode optical fiber with core and cladding diameters of 50/125. It has been shown that the presumption of the significant influence of the coating on the mode parameters of the weakly curved optical fiber has not been confirmed.

The work presents an approximate solution for the mode coupling of a curved optical fiber. Formulas for calculating the mode coupling coefficients are obtained from the Gauss approximation method. As an example, the results of the calculation of the mode coupling coefficients of a curved optical fiber with a limited parabolic refractive index profile for the proposed formulas are given. Calculations have shown that even relatively small bends of an optical fiber result in a mode coupling between modes of different azimuthal order. At the same time, mode coupling of different azimuthal order increases with reduction of bend radius and mode coupling of the same azimuthal order practically does not depend on it.

The article first proposed a method for controlling the radio emission of phased array - using chirped signals. A significant element is the “Chirp To Amplitude” (CTA) converter, which is currently (in explicit form) not represented either in the telecommunications market or in the literature.

The main drawback of the modern microwave photonic sensor systems is the absence of addressable fiber optic sensors, as a rule, based on fiber Bragg gratings, which leads to the need to build complex sensing systems and interrogators that are tuned to different wavelengths or combined into groups according to the common central wavelength. We proposed addressed fiber Bragg gratings, which structures can be realized in two variants: with two symmetrical phase π-shifts in one grating (2π-AFBG) or two serial gratings with different Bragg wavelengths (2λ-AFBG). Their common feature is difference frequency between two phase shifts or two gratings, which is lying in microwave range and defining its address, wherein addressed gratings have the same Bragg or central wavelength. So, their interrogation can be realized in microwave range by evaluation of envelope characteristics of beating signal on addressed frequency components. Despite many advantages and a wide range of applications, address gratings have one drawback – the high probability of coincidence of address frequencies and false frequencies that occur when sensors work in an array and almost arbitrary shift of the central wavelengths of some gratings relative to others. In order to eliminate this drawback, we converted twocomponent gratings into three-component ones. Thus, the gratings began to possess not one, but three addresses at the same time, and the probability of collision decreased three times. If an erroneous measurement at one address frequency is, it can be corrected according to data at two other address frequencies. A new microwave photonic sensor systems class is called “MicroWave Photonic Sensor Systems based on Three-Component Addressed Fiber Bragg Gratings”. The concept of new class sensor systems is presented. The sets of analysis and synthesis problems, measuring level design for point, few sensor and multi-sensor variants, and principle of joint field of multiplexed sensors construction for system are considered. When implemented, the interrogation speed can be increased to hundreds of MHz, the resolution is up to units of Hz, which is determined by the parameters of microwave (not optical) processing, cost of system, its exploitation and design complexity are drastically decreased.

The work presents a concept of microwave-photonic sensor system (MWPSS) for real-time distributed acoustic sensing (dynamic mode) and temperature (quazi-static mode) measurements in underground cable power transmission lines with embedded fiber optic sensor cable. The proposed MWPSS is based on the addressed fiber Bragg structures (AFBSs), consisting from two symmetrical ultra-narrow fiber Bragg gratings (2λ-FBG) each, written in this sensor cable. AFBSs have common middle wavelength, and its ultra-narrow FBGs have equal bandwidths and unique address frequency spacing between them, thus realizing the microwave-photonic interrogation method by means of beating signal detection on address frequencies. Continuous broadband laser radiation from a laser source, passing through a pass band frequency filter, generates laser radiation with a width equivalent to the measurement range. The radiation goes to AFBSs array and reflected from it passes through an inclined filter – trapezoidal optical filter. Then we got only reflected address components of AFBS and their beating at the output of photodetectors. Therefore, as we know addressed frequencies, we can realize multiplicative optical response analysis allows to define the middle Bragg wavelengths shift of each AFBSs in array and to correlate it with the value of the influencing physical fields (acoustic vibration and temperature). These values, got by interrogator, are output parameters from MWPSS. This analysis are realized in radiofrequency range, so the accuracy as for quazi-static and dynamic modes of measurements is better than for systems with optical interrogators.

The reflection and transmission of TE and TM polarized extremely narrow wave beams which are oblique incident on the dielectric interface are analyzed. Disappearance of the Brewster angle and total internal reflection effects for the strongly focused beams is predicted. The change in beam profile after reflection and transmission for different polarizations, incident beam spots and incidence angles is analyzed. Experiments using NSOM (near-field scanning optical probe) fiber probe with an aperture diameter 50 nm are conducted. It is demonstrated that substantial output light intensity increase occurs at the probe end/glass plate interface.

The spectrum of modes of cylindrical optical fiber is determined analytically by solving the three-component field Maxwell’s equations using the perturbation analysis. The frequency shift of modes in a graded-index fiber due to nonparaxiality and polarization effects is demonstrated. The degeneracy lifting of modes with distinct orbital angular momentum (OAM) and polarization (spin) but the same total angular momentum due to the spin-orbit (vector) and tensor forces is shown. Generalized Stokes vectors consisting of nine real parameters in terms of irreducible spherical and Cartesian tensor operators are considered to describe the 3D electromagnetic field. Vector and tensor polarization degrees are proposed to characterize the polarized beam.

Evolution of the polarization vector in an isotropic multi-mode graded-index optical fiber is investigated theoretically. It is shown that the rotation of the polarization vector increases with increasing axial displacement and the angle of inclination of the incident beam to the waveguide axis according to the quadratic law. The influence of polarization of light beam on its geometrical characteristics at propagation in a two-dimensional isotropic graded-index medium using the methods of coherent states is investigated. In a paraxial approximation taking into account the second order terms in a vector wave equation the expressions for the trajectory and width of linear- and circularly- polarized radiation are obtained. It is shown that the circular polarization leads to the rotation of the propagation plane of the meridional rays and additional rotation of sagittal rays, depending on the axial shift of the incident beam.

In this article we present the brief review of different scenarios of using the photonic integrated circuits (PIC) in the swept-source optical coherence tomography (SS-OCT) with different degree of integration and propose implementation of PICs on the Si/Ge manufacturing technology with integrated analogous balanced photodetectors. The first PIC implementation contains two arms for processing backscattered light and light reflected in “off-axis” mode on the same chip. We present results of simulation of such PIC that demonstrate its functionality. The second PIC implementation provides functionality for the optical processing of the backscattered signals and includes integrated narrow-band filter based on the adjustable unbalanced Mach-Zehnder interferometer for reseting the digital signal processor in the beginning of the every period of the frequency sweep. Implementing the SS-OCT functionality on the PIC will make possible to reduce the cost of the final device, as well as significantly reduce its geometric size, which is an important factor that provides portable use.

The results of theoretical and experimental study of the vibration sensor based on the few-mode optical fiber are represented in paper. The mode composition of telecommunication single mode fiber working in few-mode regime was obtained by theoretical calculation and experimentally approved. The detection of acoustic influence on few-mode optical fiber was demonstrated and impact of relative mode excitation and state of polarization was registered.

We present design of photonic integrated orbital angular momentum (OAM) emitters consisting of access waveguides and ring resonator with top grating made from holes. Access waveguides are coupled to the resonator using “pulleycoupler” scheme. The device is designed for silicon-on-insulator (SOI) manufacturing platform. We simulated singlemode resonator with one access waveguide and shown that it emits two OAM modes in out-of-plane regime. Than we simulated multimode resonator with two access waveguides and shown that it emits up to four OAM modes. The implementation of OAM emitter based on the ring resonator has specific resonance spectrum therefore such devices are WDM compatible. Compactness of such device allows using it in photonic integrated circuits.

In this paper we propose design of the mode converter for implementing in photonic integrated circuits. Mode converter consists of single-mode ring resonator, single-mode access waveguide and multimode access waveguide, and we propose using of vertical coupling, i.e. locating waveguides under the ring with little gap. Using finite difference time domain simulation we showed high efficiency of proposed device design. We showed dependence of the device performance on the shape of multimode waveguide coupler: straight waveguide provide low level of mode crosstalk, “pulley coupling” scheme with small arc angle (about 13 degrees) provide strong wavelength selectivity. Devices with proposed design is suitable for SDM-WDM systems.

We report the experimental studies on the thermal deposition of CdTe films. The deposition of thin CdTe films is performed onto the substrate of varying temperature. The characteristics of the deposited CdTe films are studied using Raman spectroscopy, scanning profilometry, and scanning electron microscopy. According to the measurements, thin CdTe films deposited on substrates with temperatures of 300 °C and 450 °C demonstrate the best stoichiometry. The processes of changing the stoichiometric composition of CdTe films were studied by exposing the films to plasma at a high-voltage gas discharge. The optimal regimes were obtained to achieve 5 % excess and 12% deficiency of Te in the fabricated CdTe films. The optical properties of CdTe films in the visible and infrared ranges were studied. We experimentally demonstrate the resonances in spectra of CdTe-based metal-dielectric structures including layers of water, isopropanol, and ethanol, which can be used to determine the concentration of these solvents.

In this paper, a two-element sensor of relative humidity of a parallel structure is proposed for consideration, which differs from the existing ones by using address fiber Bragg gratings made in SMF-28 fiber. One of the grids has a quartz shell replaced by polyimide, synthesized using a fiber coating with a full multiplicative response to temperature and deformation caused by humidity. The second grating recorded in a standard fiber and responds to temperature. It is possible to include an additional third grating with a partially etched cladding, which can be used for refract metric measurements of the amount of condensed moisture on the elements of a complete switchgear. All gratings are identical, have the same Bragg wavelength, after manipulating their claddings, but differ in a unique address, which is formed by recording two transparency windows in each of the gratings with different difference frequency space. The transparency windows correspond to phase π-shifts symmetrically located at the same distance from the center of each of the gratings. The structure obtained makes it possible to record information of the measurement conversion at the indicated difference frequencies in the radio range, which significantly increases the speed of measurements of relative humidity and their accuracy by an order of magnitude. In addition to what has been said, it is possible to note the possibility of building a network of these sensors in consecutively arranged switchgear devices, with a different radiofrequency address group being used in each of them.

The paper presents the concept of a microwave photonic measuring system based on addressed fiber Bragg structures with a polarization multiplexed response. Mathematical models of response of such structures have been developed and verified by computer and physical modeling. The possibility of constructing transverse load sensors that do not require the introduction of additional sensors for temperature compensation of the Bragg grating wavelength shift is shown. A device for interrogating such sensors is proposed and verified.

The paper discusses mathematical modeling of the optical spectrum of the addressed fiber Bragg structure. The approach uses Lorentz function to describe the spectrum of the transparency window of the addressed structure with two symmetrical π-phase shifts. The approach allowed to define the influence of the width of transparency window on the amplitude and the full width at half maximum of the address frequency spectral component. The obtained relations can be used to estimate the bandwidth of the electric bandpass filters necessary for signal detection, as well as the desired level of optical power of the light source.

The article discusses a possibility of modeling responses of addressed fiber Bragg structures (AFBS) using the normal Gauss distribution function. The presented study is motivated by the fact that for the reliable operation of the microwave photonic measurement system based on the use of address structures with two identical narrow-band bandwidth responses (2λ-FBG), it is necessary to ensure that a bandwidth of an inclined filter covers the operating range of the AFBS. Since this filter is necessary for estimating a shift of a central wavelength of the AFBS by determining a change in amplitudes of oscillations at a photodetector, which allows measurements of various physical fields without the use of expensive interrogators.

The paper considers a new approach to image edges detecting. It is based on the weight image model application. In this model, image pixels are evaluated in terms of their importance for perception. For this we use energy signs, the calculation of which is based on the wavelet transform. The proposed approach allows you to create an effective edge detector for use in various computer vision systems, for example, in aviation systems, traffic control systems, road surface monitoring systems, biometric identification systems, etc.

The paper discusses approaches to the numerical integration of the second-kind Manakov equation system. Emphasis is placed on the transition from writing equations in dimensional quantities to equations in dimensionless units. A combined explicit-implicit finite-difference integration scheme based on the implicit Crank- Nicolson finite-difference scheme is proposed and substantiated, which allows integrating a non-linear system of equations with a choice of non-linear term at the previous integration step. An algorithm for leveling the disadvantage associated with the definition of the nonlinear term from the previous integration step is proposed. The approach of automatic selection of the integration step, which reduces the total number of integration steps while maintaining the required accuracy of the approximate solution, is substantiated. Examples of the calculation results for some values of the disturbance propagation are given. The limitations imposed by the scheme on the length of the integrable fiber section are described, and approaches are proposed that eliminate these limitations without the need to increase the dimensions of the finite-difference scheme arrays. Requirements for initial boundary conditions were discussed.

The paper presents results of statistical simulation (SS) of a distributed random antenna (DRA) using the triad-cluster method (TCM) with a basic element in the form of a triad elementary radiator (TER) and the spatial analogue of the Huygens-Kirchhoff principle. Ways of solving internal and external problems, including the formulation of the initial conditions and the principles of studying characteristics of the electric and magnetic field strength vectors for TCMmodels of DRA are considered. The presented results of DRA study demonstrate the statistical characteristics (histograms of levels) of the E-field and the H-field strengths, which make the decision maker (DM) possible to understand and reproduce the physical processes that accompany formation of the EMF-channel of confidential information leakage via DRA.

To analyze the ability of certain beams to maintain information stability under the influence of random fluctuations of the optical medium, numerical calculations based on turbulence simulators such as diffusers, scattering screens and turbulence cells are used. These turbulence simulators can be generated via the Karhunen-Loeve expansion, which is a basis of the eigenfunctions of the correlation operator. In this paper, we consider an analytical calculation of the Karhunen-Loeve functions for a two-dimensional correlation function defined in the form of a Gaussian function, as well as numerical calculation for various four-dimensional correlation functions.

The paper proposes using a two-zone different level Fresnel lens to increase the depth of field. On the one hand, such a diffractive optical element can reduce the weight of the device compared to, for example, cubic phase and binary axicon apodization. On the other hand, such an element has a simpler structure compared to a harmonic lens or free-form DOE. A neural network is used to restore the image. Optimization of the surface relief of the proposed two-zone lens is performed.

We suggest a method for visualizing minor changes in a medical image. Human vision has natural resolution limitations. Monitoring and analysis of minor changes in the medical image off-limits to human vision allows to draw the doctor's attention to possible problems and helps in disease diagnostics. To monitor the changes in the medical image, we used its transformation based on the solution of a special case of the knapsack problem. Transformation of the medical image allows to capture changes in a digital image with an accuracy of one pixel. The transformed medical image is adapted for the perception of human vision. One-pixel changes in the image are well captured by an untrained operator. Testing the method of the transformed medical image on X-ray images of the temporomandibular joint showed the following: the transformed images of fragments of healthy bone tissue on different parts of the jaw have similar shape and approximately the same color scheme. The shape of the transformed image of bone tissue after treatment is similar to the transformed image of healthy bone tissue. The shape and color scheme of the transformed image of diseased bone tissue do not match the shape and color of the transformed image of healthy bone tissue and the transformed image of bone tissue after treatment. Therewith, relatively small transformed image files can be used for preliminary remote diagnostics. The full files shall be transferred only if the doctor detects particular deviations from the norm on the transformed images. The proposed method of the medical image transformation can be used for remote detection of diseases and in other areas of medicine.

Panoramic television images are used in a wide range of applications, including scientific and applied television, video surveillance systems, vision systems used in transport and robotics. The construction of panoramic images can be performed by assembling from several frames obtained using one rotary television camera or several stationary television cameras. However, such methods cannot be used for working with moving images, as well as in systems of mobile robots, where strict requirements are placed on the reliability and dimensions of the equipment. In these cases, the preferred method is the formation of a panoramic image using a TV camera with a high-resolution photosensitive sensor in combination with an ultra-wide angle lens such as fisheye. The article discusses one of the methods of forming a panoramic image in real time with field of view (FOV) corresponding to the hemisphere of 360 x 180 degrees.

Multidimensional optical signals from triangulation sensors are described the highest level of information. In particular, it allows defining the object counter. The counter is allowed measuring solid deforming. The original superposition method was shown at this article. It includes the defining reference points at a counter of object etalon and calculates the line equations as approximation points of measured counter in area of reference points. Superposition by reference points and line equations allow solving the problem preliminary decomposition measured counter to fragments.

The triangulation optical sensors are widespread at industry. In particular, they are used at development of railway diagnostic system. The output signal of this sensor is multidimensional point sequences. At every single moment the signal defines the counter of target object. In the case it is rail counter. The one of important problem is method‘s development for recognition railway objects is the railway switch. The recognition method was shown at article. It is based on measurement side point of rail. At the area of switch triangulation optical sensors recognition at the same time two rails. The processing of railway parts allows recognition this situation.

This article was described the task offset and rotate measurement for video signal superposition. The developed algorithm is generalization of Lucas-Kanade model. Another name of this model is optical flow algorithm. The original algorithm allows to rate offsets parameters, but developed algorithm also allows to rate rotate angle. The concept of superposition has based on Taylor series of signal and sinus and cosines replacement on approximate function.

The method of recognition rail fishplate was shown at this article. The method was developed for track geometry car. The automation the process of measuring is the one important thing, which improves the railway safety. The check of recognition object takes much less time than the viewing of all track video data. So the information about railway condition is quickly given to railway expert. The article is interested for developer of video data processing.

Different methods for creation of 3D image files, including integral imaging, 2D + z files and 2D images captured at different view angles, are considered. It is found that the disadvantage of the integral imaging method for capturing is the small depth of the 3D image. It is demonstrated that the capturing an object from different angles using a rotating platform and a conventional camera makes it possible to obtain a higher depth. Large 3D images using Full HD multiprojectors and Ultra HD 4K projector are created. 3D displays based on mobile devices are also developed.

Current trends in increasing the intelligence level of software systems for analyzing data flows under the constraints of processing time require the study of new technologies that take advantage of a distributed computing environment. In this paper, we implement a technology for distributed streaming processing of multidimensional optical signals based on the Apache Flink framework. The technology is studied on the task of transport video surveillance tracking unique objects captured by a system of geographically dispersed video cameras. We study the ability of proposed solution scale the processing depending on the amount of resources in the cloud, the quantity and quality of optical signals. The characteristics of processing processes of a set of frames of varying complexity on a computing cluster are investigated. NVIDIA AI City Challenge is used as test data sets.

This article is devoted to the problems of radar sensing. Herein, we have considered the tasks of modeling and recognizing radar images. The modeling technology was based on the independent creation of terrain models and objects, which were then integrated into a three-dimensional (3D) scene. This approach enabled the operative creation of a number of image variants of different classes. Recognition methods and algorithms were based on the use of the so-called conjugacy index as a measure of proximity. At the same time, support subspaces of the minimum dimension were formed by vectors, components of which were samples of the radar image. Problems of higher accuracy of recognition due to a division of classes into subclasses and a combination of the support subspace method with the neural convolutional networks were considered.

In this paper, we study the possibility of forming beams with a scalable wavefront. To multiply the wavefront with a scale factor, it is proposed to use a combination of the wavefront distribution generator and a diffractive grating with binarization operation. It is shown numerically and experimentally using spatial light modulator that such beams as the Zernike basis functions and Airy beams are suitable for testing optical systems.

The paper presents a model for predicting the service life of an optical cable on an operated cable line. The results of calculations for two cables samples removed from the cable line after several years of operation are provided. The proposed approach allows us to take into account the piecewise regular distribution of loads on the optical fiber in the cable both in the past and in the future. The model allows you to calculate predicted estimates of the cable service life, provided that the load on the optical fiber in the cable in the future and the history of the load on the optical fiber in the past are known. This, in turn, requires knowledge of the statistical characteristics of technological processes for cable production, construction and technical operation of the cable line.

In this paper, we propose a Prony’s decomposition-based data processing algorithm for measuring the distribution of excess fiber length in an optical cable by a known method, which based on measurements of the polarizing backscattering characteristics of an optical fiber at a positive and low temperature below zero. The results of processing experimental data are presented and error estimates are given.

This paper presents a simple method for localization of events on traces of group of optical fibers from the same fiber optic link segment (FOLS) of a fiber-optic transmission line (FOTL). This method is primarily focused on determining the location of the most "problematic" for the automated search events "without reflection," which fit to optic fiber fusion splices with insertion loss significantly less than the standard values and simultaneously related values of backscattering coefficients of fused optical fibers. Proposed solution is based on comparison of tables of events for measured traces with test of condition of check sum of distances to the same event in backward directions relative to optical length of fiber optic link segment and condition of belonging of pair of events on traces of different optical fibers of the same direction to one event. As a result, it is possible to make a conclusion about the presence of this event on all other traces of the group. Further, corresponding corrections are made in tables of traces with missing events.

This work presents fast and simple method for estimation of the insertion loss at the connection of two singlemode optical fibers with contaminated fiber optic connector ferrule end faces. Proposed solution is based on the fundamental mode coupling coefficient (or e.g. transmission coefficient) evaluation via discretized mode field overlap integral. It is represented in the form of nested sums on radial mode field distributions, which are described well by Gaussian function under weakly guiding approximation or may be taken from the mode field distribution matrix, computed by rigorous numerical methods during analysis of real optical fiber samples with nonsymmetrical geometry. Proposed approach provides ability of taking into account the mode field distortions, occurring due to end face contaminations, by directly overlapping of connector ferrule end face image over discretized mode field radial distribution. We present some results of developed method approbation on really measured fiber optic connections between standard singlemode optical fibers with various order contaminated ferrules.

In this paper the method for interrogation of Brillouin scattering signal from sensing fiber is proposed. The essence of the method consists in the application of the single pump source to generate reference signal due stimulated Brillouin scattering in thermally stabilized reference fiber spool and for probing the sensor fiber. As result of heterodynes in receiver the signal at beat frequencies is analyzed. The requirements for pump power and reference fiber parameters are defined theoretically and experimentally. The results of experimental estimation of beat signal are represented.

The article considers a new type of equipment for unmanned aerial vehicles based on the use of diffractive optical elements for imaging and deep learning for the subsequent real-time image quality improvement.

This paper describes the operation of the prototype of the Radio-over-Fiber telecommunication system with the generation of OAM signals in the W-band. A method for generation both a radio and an optical OAM signal in RoF is proposed, a method for useful information transmission using OFDM technology in the considered system is described, an approach to converting optical vortexes into the radio domain is proposed, and a feedback channel simulation in RoF systems using OAM signals is carried out.

In this paper, an alternative fiber-optic method for forming vortex modes based on a chiral (twisted) microstructured fiber is proposed. This fiber can be considered as a ring-core fiber with ring core formed by capillaries. Besides, optical fibers design for transmitting optical vortexes over long distances. i.e. a vortex-maintaining fiber is also proposed. This fiber is a multimode fiber with an extremely large core. A comparison of the different types of vortex generation and vortex-maintaining fibers is also given. Both proposed fibers can be used in Radio over Fiber systems applying vortex beams.

We propose and fabricate pilot lengths of two type microstructured optical fibers with chirality, induced during the drawing process under 10 and 66 revolutions per meter. The first one is microstructured fiber with geometry providing quasi-ring radial mode field distribution. So it imitates ring-core optical fiber properties by special formation of designed 2D-periodic structure. The second is fiber with hexagonal geometry and shifted core in relation to central axe. The work presents results of numerical analysis of fabricated samples, performed by rigorous numerical method. Here initial data were set via manufactured optical fiber end face images. We also reports some results of far field laser beam profile images, measured at the output of described fiber samples under laser source excitation at wavelength 1550 nm.

The propagation of vortex beams of wavelength 1530 nm through an aerosol and turbulent atmosphere was experimentally investigated. The stability of a vortex phase under the beam wandering caused by a flow of warm air was experimentally showed. The results obtained can be used for optical atmospheric communication.

Sets out the principles and categorized the modern methods of adaptation of photosensor arrays and digital images encoding when changing multivariate statistics subjects. A functional diagram of a system for automatically controlling discrete states of a photodetector based on the results of evaluating one of the statistics is presented. A brief description of the main methods of adaptation of video information systems is presented. The block diagram of a multi-circuit adaptive video information system is given. The work of the adaptive system is illustrated by a time diagram on the example of the work of the spacecraft rendezvous control system.

In this paper, we propose the option of constructing a multi-channel system of quantum key distribution with frequency coding based on the AMPM-PMAM electro-optical scheme, using a Comb generator, multiplexer and demultiplexer to form a set of parallel quantum subchannels. The AMPM-PMAM work of the QKD system is based on the modulation conversion of the photon carrier based on the Ilyin-Morozov method and its one- and two-modulator implementations. The application of this scheme will significantly increase the transmission speed of the quantum key, allow the use of several levels of cryptographic protection, reduce the likelihood of achieving a positive result in PNS attacks of Eve (illegal subscriber) by eliminating the carrier from the structure of the signal transmitted through the quantum key distribution channel, and splitting information about key to different independent quantum channels.

The meaning of project management, soft skills concepts is analyzed. Various theoretical and methodological approaches to the soft skills topics are presented. The psychological and pedagogical study findings made from 2016 to the present are analyzed, indicating the adjustment methods and programs for soft skills and hard skills development levels. The indicators of emotional intelligence and critical thinking as important components in the structure of the soft skills set have been reviewed. A blueprint of soft skills development through result-oriented project management program for students studying optical communication systems is proposed.

Approaches to building cross-functional competences are analyzed taking into account educational standards' and employers' requirements. Project-based approach as a way of building cross-functional competences is reviewed. It is a proprietary project, which gives an insight into the future professional activity, and important professional competences of an expert in infocommunication technologies and communication systems.