This PDF file contains the front matter associated with SPIE Proceedings Volume 10774, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing

The fiber optic communication systems are the basis for ensuring global communication of the modern society. High bandwidth and low noise are the main advantages of the indicated class of communication systems. Nevertheless, fiber optic communication systems have a series of confounding factors arising because of the temporary operation, and due to the used fiber optic cable. To compensate for such manifestations it is necessary to use modern error-correcting codes and their decoding methods. In the work proposed to use polar codes and the lexicographic method of decoding.

The main advantages of polar codes are the ability to achieve bandwidth, binary symmetric channel of communication, high adaptation to the end-user and acceptable level of correcting capabilities. In the based lexicographic approach is the method of clustering of the space of allowed codewords. Technology of division clusters or lexicographic ordering of the space of allowed codewords of error-correcting binary block codes implements non-algebraic approach to the processing of code vectors of the receiver, allowing to reduce the computation cost and to provide energy gain.

The article is devoted to the development of an automatic system for switching fiber-optic communication lines to a reserve in the event of emergency situations using switches controlled by a decision device. In the development section, a description of the optical communication line with automatic redundancy is provided by the operation of the decision device using a transfector based on logic elements made on a GaInAs crystal. In the practical part, a simulation of the optical communication line and the decision device with the matched parameters in the OptiSystem program was made. Waveforms and signal patterns of the signal on the main and backup lines are presented.

The expression for electron count optimal threshold value has been obtained in the article, the expression for evaluation of potentially achievable average error probability value during binary signals differentiation by an optical receiver with consideration of synchronization error has been refined. It has been shown that a time interval error switches the receiver into a mode that does not provide minimal average error probability. This explains a significant increase in error probability, which is mostly caused by errors during transmissions of “zeros” due to a lowered count threshold value. The obtained results enable us to determine synchronization error exchange conditions on optical signal power with a predetermined average error probability value, and to substantiate synchronization precision tolerances.

The problems of statistical analysis of a typical receive optical module (TROM) in the detection of a random optical signal and the synthesis of an optimal algorithm for discrimination of the optical signals in a binary communication system are solved in a paper. The envelope of optical field intensity is described by the Nakagami distribution density. Conditional Poisson distribution of the photoelectron counts and its asymptotic approximation, during limitation of the detection process by thermal noise is obtained. Statistical model of the signal and noise mixture at the TROM output consider the dynamic range of optical signal. The synthesis of the Bayesian algorithm for signals discrimination is performed taking into account the restrictions imposed by the preset TROM structure. The average error probability of signals discrimination is estimated. Conditions for feasibility of the synthesized algorithm are discussed.

To meet the ever-growing demand for the throughput of the wireless communication technologies, one way is to use light beams multiplexed by the orbital angular momentum (OAM). However, the intensity structure is often ignored, although it can carry additional information and thus lead to increase of the throughput. Some distortions of the vortex phase also can lead to modified intensity. Here, we analyze an elliptic optical vortex embedded into an elliptic Gaussian beam. Explicit closed form expressions for the normalized orbital angular momentum (OAM) of such a beam and for its complex amplitude after propagation in a paraxial ABCD-system are derived. The resulting elliptic Gaussian vortex (EGV) is shown to have a fractional OAM, whose maximal value equals to the topological charge n of a conventional Gauss vortex is attained for a zero ellipticity vortex. As the beam propagates, the major axis of the intensity ellipse in the beam cross-section rotates, making the angle of 90° between the initial plane and the focal plane of a spherical lens. On the major axis of the intensity ellipse, there are n intensity nulls of the EGV, with the distance between them varying with propagation distance and varying ellipticity. The distance between the intensity nulls is found to be maximal in the focal plane for a given ellipticity. This distance between the nulls can be used to decoding the data encoded by the vortex ellipticity.

The paper considers the study of chirped optical signal application methods in perspective optical networks: RoF, PON and MAN categories. The principle of obtaining chirped optical pulses due to Mach-Zehnder chirping modulator control modes selection is proposed. A mathematical model is developed. It is shown that iterative selection of corrective chirp function is possible. The experimental approbation of the proposed principle is performed. It is also shown that the chirp function can be used to design all-optical network control devices.

This work presents method for computing dispersion parameters of guided modes propagating in commercially available telecommunication silica optical fibers with large core diameter. These real optical fibers differ from model ideal representation by non-symmetric geometry of transversal cross-section in both radial coordinates and refractive index profile form. We propose solution for detailed reconstruction of researched optical fiber 3D-structure by limited data from the protocols of refractive index profile measurement by conventional lab kits of optical fiber analyzers over conditional transversal cross-sections “X” and “Y”. It is based on irregular mesh with nodes laying on cross-section semi-axes corresponding to refractive index profile extremums that provides following implementation of triangularization procedure to form the adaptive mesh for researched fiber representation during its analysis by rigorous numerical methods. We performed computing of guided mode staff transmission parameters for commercially available sample of multimode optical fiber 50/125 of Cat. OM2 with great core asymmetry and strong refractive index profile distortions by recently developed modification of mixed finite element method adapted for analysis of optical fibers with large core diameter. Computation results were compared with data of analysis proceed by the same approach for model ideally symmetric multimode optical fiber with structure repaired also from the same sample measurement data but considered only from the one semi-axis.

Vortex laser beams possessing an integer orbital angular momentum are promising for compaction of communication channels in the transmission of information by means of free-space optics. We consider vortex beams representing a superposition of the Laguerre-Gaussian modes with different indices, so they have a fractional orbital angular momentum. Such beams enhance the capabilities and improve the security of information transfer. We consider the propagation of vortex laser beams in a random medium based on the extended Huygens-Fresnel principle. To determine the modal composition of the considered beams under the conditions of random distortions we propose to use multichannel diffractive optical elements (DOE) matched with optical vortices.

We present alternative method for implementation of secure data transmission channel protected over physical layer for the "first/last mile" segment of intra-corporate network by specialized fiber optic link. Proposed solution is based on application of operating in a few-mode laser-based regime multimode optical fibers with special refractive index profile providing optical pulse strong uniquely distortions due to differential mode delay effect that allows to consider those optical fibers as "encryptor". Therefore, transmitted traffic is strongly distorted and it is unable to be processed without corresponding "decryptor" which might be either also another one optical fiber with "inversed" refractive index profile in relation to the "encryptor"-fiber or electronic dispersion compensator device modified for such application. This work is concerned with configurations of proposed "crypto" fiber optic link as well as brief description of math apparatus for design it. Some results of preliminary simulations are also represented.

In this paper, the example of simplex low-rate acousto-optical fiber link is considered. The method of data transmission by acousto-optical fiber link is examined. The model of data transmission based on this method is deacribed and the simulation results of data transmission on acousto-optical fiber link are presented. The estimations of bit errors obtained from the simulation have demonstrated the potential possibilities for data transmission based on the considered method of design of acousto-optical fiber link.

This paper presents the results of a theoretical study of a photonic block with an electro-optical modulator and photodiode. On the basis of this line, frequency converters of microwave signals are performed. The results of experimental and theoretical studies of a broadband radio-photon microwave frequency doubler are given.

The influence of regular longitudinally inhomogeneous sections of the waveguides on the level of modal noise, and its dependence on the degree of both spatial and temporal coherence of the radiation source are investigated using the mode approach. The way to reduce modal noise at the joints of waveguides with matching sections between the waveguides is proposed. It is shown that under the matching condition the complete suppression of modal noise due to the joint is possible. A way to reduce modal noise by using random microlens arrays and holographic diffusers is also proposed.

The paper describes the results of experimental investigation of the bench, which represents UWB RoF communication system. This bench performs the first prototype of such system and allows it to study from different sides and on different scales. The whole scheme of the bench as well as the detailed description of its elements and characteristics are presented, also the specific issues regarding the connection of the elements are observed. The specific feature of this scheme is application of the phased antenna array as the radiating element of the radio part, which revealed the uncommon questions of matching RoF signal, being transformed from optical into radio domain. The experiment methods are explained in detail. The obtained results are presented and thoroughly analyzed, which revealed that the bench characteristics satisfy the thresholds, set before. Also the experiments on data transmission proved the possibility of successful high-speed data transmission in IR-UWB frequency range on the basis of Radio-over-Fiber technology.

We describe mathematical tools that enable the reflection of light at a diffraction grating applied on a freeform surface to be modeled. To address the problem, we use an analog of the Kirchhoff's method. By way of illustration, reflection at a diffraction grating applied on a spherical surface is analyzed. To enable the modeling of such systems, the software was developed and numerical study was conducted. The feasibility to generalize the results onto freeform diffractive optical elements is studied.

Beam combiners and splitters based on the frustrated total internal reflection, diffraction and refraction effects of light beams are considered. New high efficiency prismatic beam combiner consisting of uniform material is proposed.

Glassless multi-view projection display system that combines the modules of capturing three-dimensional objects, image processing (creation of 3D files) and display screen with a holographic diffuser is presented. Optical simulations of lenticular and two-dimensional microlens arrays are performed with the aim to determine optimal lenticular sheets, view angle, view number, depth, etc. Effects of crosstalk and ghost-imaging are studied both numerically and experimentally. Multi-projector system is designed and 3D images on 30-inch screen are demonstrated.

Propagation of strongly focused light beams in graded-index planar waveguide and cylindrical fiber is investigated using exact analytical solutions of the wave equation. It is shown that high efficiency transfer of a strongly focused subwavelength spot through optical waveguide over large distances takes place with a period of revival (regeneration). Intensity distributions of a focused light beam and focusing efficiency are simulated. Super-oscillatory hot-spots with the sizes which are beyond the conventional Abbe diffraction limit can be observed at large distances from the source. This can provide the possibility to detect optical super-resolution information in the far-field without any evanescent waves. Far-field super-resolution imaging capabilities of a graded-index waveguide are also analyzed. It is shown that the vector-vortex Laguerre-Gauss modes with polarization-orbital angular momentum (OAM) entanglement are the vector solutions of the Maxwell equations in a graded-index cylindrical waveguide. The wave shape variation with distance taking into account the spin-orbit interaction and nonparaxial effects is analyzed. Effect of long-term periodical revival of wave packets due to mode interference in a graded-index cylindrical optical waveguide is also demonstrated.

The diffraction patterns of vortex damped fields formed in the near zone of an optical fiber tapper and a subwavelength diffraction axicon with a numerical aperture more than 1 were obtained numerically using the finite difference time domain (FDTD) method and the finite element method (FEM).

This work presents some results of attempt to apply earlier on developed extended modified Gaussian approximation utilization for computing dispersion parameters of arbitrary order guided modes propagating in weakly guiding nonsymmetrical multimode optical fibers with arbitrary complicated graded refractive index profile. Fundamental mode as well as some higher-order guided mode parameter were estimated and matched with results of computation performed by rigorous mixed finite element method. Here 3D-structire of analyzed optical fiber was set by reports of refractive index profile measurements produced for sample of multimode optical fiber 50/125 of ISO/TIA Cat. OM2 carried out by commercially available equipment lab kit. Spectral curves of normalized propagation constants and mode delays computed over “O”-band by mentioned above rigorous and approximate methods expanded for analysis of non-symmetrical optical fibers with large core diameter and complicated refracted index profile are compared.

In this paper is described an approximate analytical solution for the fundamental mode of the step-index optical fiber with taking into account the Kerr nonlinearity. The solution is obtained by a known method of Gauss approximation. Based on the obtained analytical solution there were calculated the spectral dependencies of time delay and first and second order chromatic dispersion the parameters for mode LP₀₁ of the sample of the step-index optical fiber.

The preliminary data of studying optical gain properties of active media using the open aperture z-scan technique without an additional probe beam are demonstrated. The prospects of evaluating pump induced photodynamic processes parameters in UV solid-state active media on the pumping and lasing wavelengths: excited-state absorption and photoionization cross-sections of active ions, effective absorption and ionization cross-sections of color centers and recombination rates are discussed.

In this paper is described the approximate solution for the LP11 mode of the step-index optical fiber with taking into account the Kerr nonlinearity. The solution is obtained by a known method of Gauss approximation. The special case of only one LP11 mode propagation in lightguide is considered. The calculation of spectral dependencies of equivalent mode spot radius, time delay, chromatic dispersion of first and second order was evaluated. Results of calculation are presented in this paper.

I analyze physical approximations and mathematical tools used when modeling diffractive optics elements and devices. Examples of the numerical simulation of focusing optical elements and a space-based Offner hyperspectral imaging spectrometer (hyperspectrometer) are presented. The design of the hyperspectrometer features the use of a diffractive optical element on curved surfaces. The modeling results show that the hyperspectrometer under study offers optical characteristics superior to those of a similar device based on spectral filters.

In this work, an influential approach has been presented for the fabrication of an interference filter. The construction of such filters turns the layer stack assembly on its one side which makes it possible to use air as a low index material. All the layers of a particular material (high index) are deposited at the same time which transforms the layer thickness into line thickness and is obtained by patterning the filters using photolithography. This results in the formation of a complex filter design with high volume and low production cost.

Regularities of laser beam power redistribution with a change of the spatial position of the diffractive optical element (DOE) was determined, as well as changes the focal distance and the length of the focal line segment at the change of spatial position of the DOE. The performed theoretical and experimental researches allow realizing the laser beam generation with purposefully changing spatial power distribution. Measurement of the spatial intensity distribution in the laser spot was conducted with using a СО₂ laser Hebar-1A. The use of DOE as components of optical systems allows changing the shape of the laser beam and the beam intensity distribution over time.

The task of the antenna array radiation pattern optical control for ultra-wideband radio emission is considered in the paper. A fiber-optic phasing scheme is proposed, which is part of a complex fiber-optic device. The control device layout and the radio-photon segment layout photos are presented. An analytical model of the optical phasing process is developed that provides the frequency bands number calculation. The number of bands, on which a wide frequency range should be divided, depends on the permissible level of the array radiation pattern distortion. The results of experimental approbation of the radio lobe phasing control in the frequency band of 200 MHz, divided into 3 subbands of 70 MHz, are presented.

In this paper, we discuss simulation of statistical characteristics of electromagnetic field exciting the aperture random antenna in the most general and close to reality case, with application of the method of statistical simulation and computer version of Monte Carlo methods. A triad elementary radiator model instead of Huygens radiator is proposed as basic element of a random antenna. A relation between virtual currents exciting an aperture random antenna and orthogonal components of a real electromagnetic field vectors is obtained and proved. The histograms of excitation currents distribution of triad elementary radiator are obtained. The possibility of applying single-mode probabilistic laws to simulate virtual excitation currents of a triad radiator is proved. The validity of using random errors generation according to the uniform distribution law during statistical simulation is proved.

The comparative modeling of focusing of femtosecond Gaussian and Poissonian pulses was presented in this paper. Poissonian spectral shape pulses, as opposed to the Gaussian-shaped ones, allow to avoid negative frequency components. The spectral properties of pulses for various durations are investigated. Calculations showed that a significant difference between the Gauss and Poisson pulses begins only for very short durations (less than 3 fs). A comparative simulation of the focusing of short pulses, as well as the passage of focused pulses through a binary phase plate, is performed. The calculation was carried out on the basis of solutions of the Maxwell equations by the method of finite differences in the time domain.

We present results of numerical analysis of the diffraction of a plane monochromatic TE-wave on an ideal homogeneous dielectric cylinder with several resonant wavelength scale radii. Two subsequent near-surface maxima of intensity (two focuses) generated at the cylinder output were found on the optical axis. The first subwavelength focus is formed by one of the whispering gallery mode lobes. Its intensity is 50 times the incident light intensity and its full width at the half maximum of the intensity is equal to 0.155 of the incident wavelength. The second focus is two times less in intensity. Its focal spot known as a photonic nanojet is stretched toward the optical axis. The second focus is formed at a distance about the wavelength from the cylinder surface. Its width is equal to 0.44 of the wavelength and its length is two wavelengths. The influence of material absorption on the light focusing is also examined by numerical simulation.

A method is proposed for detecting birefringence of mechanically free parabolic gradient-index lenses based on the astigmatic transformation of the zero-order Bessel beam. The degree of astigmatism can be determined from the intensity distribution of the distorted beam. Similar patterns are also obtained in an experimental study of the passage of a Bessel beam through a quarter-pitch gradient-index lens, which indicates the presence of birefringence of the lens material. Comparison of experimental data and numerical simulation shows the possibility of measuring the optical path difference of no worse than 0.05λ₀ between ordinary and extraordinary beams.

The results of the development of a 6-channel microwave photonic beamforming system (BFS) for phased array antenna in receiving mode are presented. BFS incorporate DWDM technology based components of analogue fiber-optic transmission links with external modulation in RF range 0.1-18 GHz and specially manufactured chirped fiber Bragg grating. A number of BFS transmitters have six optical carriers separated with 100 GHz step (ITU grid, DWDM standard in C-band). The beamforming is realized by introducing inter-channel time delays when microwave modulated optical carriers interact with chirped fiber Bragg grating (СFBG) in reflection mode, throughout the total operating spectral range of 6-channel BFS (6x100 GHz). The used СFBG has 2 cm length. The results of measuring the S-parameters of BFS 6 channels are given, which enable to synthesize the far-field pattern of the phased array antenna with photonic BFS under investigation. Far-field patterns of four channel linear phased antenna array integrated with photonic beamformer model have been measured and compared with calculated patterns taking into account amplitude and phase errors arising in beamformer channels.

An investigation of behavior of different types of vortical laser beams in parabolic media widens a set of optical signals used for the telecommunication. Generally, Laguerre-Gauss modes and Bessel ones are regarded as vortical. However, lately researchers examine other types of laser modes which primordially not have the vortical phase singularity (for example, Hermite-Gauss modes or Airy beams) but the singularity is embedded into these beams additionally. The embedding of the vortical phase into an arbitrary laser field may be realized by means of diffractive optic tools.

In this paper the transformation of Hermite-Gauss (HG) beams with embedded vortex phase by lens system is investigated theoretically and numerically. A particular attention is attended to the formation of vortex phase singularities in focal area. It is shown, that under appointed relations between HG mode indices and the number of embedded optical vortex, the vortex phase singularity in a focal plane centre may be disappeared. The modeling of the vortical HG beams propagation through a waveguide with a parabolic dependence of the refractive index is implemented on base of the fractional Fourier transformation (FrFT).

This article describes the design principles of optoelectronic system for instantaneous frequency measurement of microwave signals based on the use of amplitude-phase modulation conversion of single optical carrier into symmetrical dual-frequency ones for additional frequency separation according its wavelength, its modulation by unknown frequency and subsequent “frequency-amplitude” measurement conversion in fiber Bragg grating with Gaussian reflection profile along with the variations of schemes for realization of this method with the corresponding spectrums. Such approach increases the signal-to-noise ratio and allows measuring of several unknown frequencies simultaneously. Distinction and measurement of the instantaneous frequencies made depending on the amplitudes and modulation indexes of the signals received at the photodetector.

In this work, we numerically investigated focusing of a quasi-cylindrical optical vortex with azimuthal polarization and a wavelength of 532 nm. It was shown that the focal spot produced by a beam with four sectors focused with a Fresnel zone plate with a numerical aperture of NA = 0.95 does not differ from the ideally azimuthally polarized optical vortex; the difference in the focal spot diameter does not exceed 0.03λ. The four-sector binary subwavelength grating polarizer was fabricated in a golden film. It was experimentally demonstrated that a linearly polarized 532-nm Gaussian beam reflected at the polarizer was converted to an azimuthally polarized beam. Putting a spiral phase plate (SPP) with the topological charge n = 1 into the azimuthally polarized beam from the micropolarizer was experimentally shown to enable the conversion of the annular intensity pattern into a central intensity peak.

In this paper is presented the simple analytical formula for calculating the coupling coefficient on an ideally matched optical fiber joint between modes with arbitrary radial and azimuthal orders. The solution is obtained by a known method of Gauss approximation. As an example, the present work shows the calculations results of dependencies of mode coupling coefficients from ratio of radii of mode spot for some low order modes.

A hyperspectrometer based on the Offner scheme was investigated. Spectral characteristics were studied and calibrated using a standard spectrometer. As a result of estimating the deviations of the spectra of the imaging hyperspectrometer and the reference spectrometer, calibration coefficients were obtained. The reflectance spectra of beets, onions and potatoes under natural solar illumination were experimentally obtained. Based on the analysis of hyperspectral imaging data, an analysis of the distribution of vegetative indices and, in particular, moisture content, was carried out. Analysis of histograms of moisture content index distribution was carried out.

The analytical expression for probability distribution density of transmission coefficient for passive linear channel of fiber-optic systems functioning under the influence of mechanical load has been obtained in the research. It has been shown that probability distribution density is sensitive to the amount of fiber microcracks and the amount of fading on each of them, and also includes the parameters that are determined by the optical fiber drawing technology.

Based on the use of axial computer-generated holograms system and coherent behavior of laser radiation sources, it is proposed to control location and alignment processes of segments of the multiple mirrors used in hyper high-aperture and superlarge optical telescopes. The possibilities of identifying the inaccuracy sign and magnitude from the given position of each of the 24 identical panels from one out of four tiers, as well as the inaccuracy sign and magnitude of neighboring tier panels interposition at the places of their “coupling/attaching” were considered, based on the example of solving a problem of controlling the location and alignment processes of the carbon panels of the multiple primary mirror in “Millimetron” space observatory.

One of the promising methods for generating continuous sub-terahertz radiation is the method of photomixing, when the photoconductive material is excited by the emission of two optical continuous lasers with frequencies separated by terahertz frequencies. It should be noted that for effective photomixing the polarization, frequencies and phases of the optical beams introduced into the mixer must be constant, otherwise it is necessary to additionally use a complex system of phase synchronization. In connection with the complexity of such an implementation, variants based on the conversion of single-frequency and broadband laser radiation into two-frequency ones were investigated. The first of these is modulation and consists in the external modulation of single-frequency laser radiation in the electro-optical Mach-Zehnder modulator. The second one is broadband with the allocation of two wavelengths using two rectangular fiber Bragg gratings with a small difference in width. The studies were carried out to create a terahertz photoconductor, the distinguishing feature of which is the use of heterostructures grown on a GaAs substrate in the low-temperature regime as a photoconductive material in the form of a thick gradient layer In(x)Al(1-x)As (x = 0 → 1) with artificially created local deformations and with photoconductive composite InGaAs / InAs / InGaAs quantum wells.

The paper presents the findings of the research into the effects of material dispersion in an optical fiber link. The general framework of normal and anomalous dispersion of the second and third orders were formulated by means of a principle of equivalence. The approach to the problem is based on a method of transforming a frequency response of an equivalent liner system into its impulse response with the use of a dispersion characteristic. This approach was used to thoroughly consider the effects of chirping, soliton (stable) propagation and collapse of solitons.

This work is concerned with development of simple method for making of alternative fiber optic Raman probe components containing silica optical fibers with formed precision micro-lens under desired configuration and geometry parameters at the fiber end face by commercially available field fusion splicer kit and its modified software settings. We present methods for writing both hemispherical lenses and ball lenses as well as tapered cones, results of their experimental approbation and results of following carried out experimental research of fusion splicer software settings impact on microlensed optical fiber geometry parameters – radius and length.

In this article the new approach of contours detection in the images using energy characteristics of wavelet transform is proposed. This approach of contours detection with added procedure of contours intensification in the binary image, their connection and description can be considered as the base of different information systems connected with image processing and analysis. Also this approach based on image representation using energy models has its own independent meaning and can be used not only for contours detection, but for salient points detection and texture features extraction.

This article was described some features of processing multidimensional optical video surveillance signals for triangulation scanner linearization algorithm. So, exactly: the obtainment source data, measurement point’s coordinate by physical location of target object, measurement coordinate of their points at photosensitive matrix coordinate system, the rating the operator transform from photosensitive matrix coordinate system to physical coordinate system. The result of linearization quality by the root mean square value was showed at conclusion. RMS value was calculated by real and measuring point’s coordinate of some part of scanner measuring filed.

The article is devoted to the development of a processing method of digital maps and satellite images using the terrain characteristic points for solving problems of emergencies. Solving one of the emergency tasks the authors analyzed the problem of constructing flooding zones in the flood period, based on the use of satellite images and digital topographic maps. As one of the problems of using digital maps and satellite images solving this task, the authors revealed the influence of image deformations and poor quantity of points for control and alignment of the satellite radar image with a digital topographic map. To solve the problem the authors have developed a processing method of digital maps and satellite images to build the actual flooding zones when the river floods, allowing to eliminate the influence of image deformations and poor quantity of control points. The analysis of the effectiveness of the proposed method showed the increase of accuracy of alignment the actual flooding zones with the digital topographic map is 40%.

This article considers the problem of deterioration in the quality of video image transmitted over coaxial cable with a length of over 260 m. The causes of the transmitted signal form distortion are described, and a method for their compensation based on the correction of the signal on the transmitting side is proposed. The results of a research of the video signal distortions compensation obtained experimentally using a hardware prototype of a pre-corrector are presented.

An algorithm is considered for searching and selecting images of licence plate of vehicles from video sequences. The specialty of the algorithm is that the object of interest investigated not as connected closed area of the foreground, but the chain of adjacent objects with symbols. At the first stage, the applicant areas for symbols of the licence plate are found. At the second stage, a mask is formed to select the image of the licence plate.

In this paper the MIMO communication system based on redundant spatial encoding, performed by cyclic enumeration of transmission channels, is presented. For this system it is proposed to represent a mathematical model of onedimensional MIMO channel in the form of a multidimensional SIMO channel. The conditions of blind channel identifiability for this model are formulated. For the blind identification of the multidimensional SIMO channel, the cross-relations method in polynomial interpretation is proposed.

Nowadays the multilayer computed tomography shots with contrast dye used for detection of small pathological growth are widespread in medical clinics. Although, tomography study with contrast dye use has contraindications and is much more expensive for patients than study without use of dye. This article proposes data processing method based on segmentation of multilayer computed tomography shots without use of dye. The method allows to automatically identify pathological growths and to detect studying object areas. The software, developed according to this method, evaluates parameters of small objects and sinuses, which occupy only small part of initial computed tomography layers, with high accuracy.

This paper describes objectives on inner pipeline fault detection device modeling designated to monitor pipeline in real time. Due to high demands to high-speed and miniature measurements of such devices it is suggested to use implementations on the basis of fiber optic and radio-photonic mode of operation. A functional equipment design containing fiber optic generation and complex optic impulses transformation transmitted into radio trunk circuits are developed. Physical implementation of the suggested model is estimated as well as an analytical model for propagation of pilot signal on the basis of the Maxwell system of equations for partially conductive and simultaneously scattering medium.

It is necessary to take into account that in the process of technical exploitation of transport multichannel communications (TMС) laid on the roadside, the components included in this system are subjected to mechanical, thermal and geophysical influences.

In this case, damage to the TMC and the pinned optical cable is possible, the TMC leakage failure leads to the filling of the pipelines with water, mud, siltation in significant areas, which deprives the FOL of all advantages in the form of the possibility of additional laying or replacement of the FOL.

Timely detection and elimination of leakage of TMС avoids adverse consequences and reduces the costs of the technical operation of the FOL.

In practice, however, maintenance of TMC is often not carried out, and the condition of the pipelines is identified when performing work with the optical cables, which significantly reduces the reliability of the FOL operation.

To improve the reliability of the optical cables, laid in the TMC, a method for monitoring the leakage of pipelines is proposed.

This article deals with problem of carbon brush`s length measurements. There are many applications where regular inspection is not feasible because of a number of factors including, for example, time, labor, cost and disruptions due to down time. Thus, there is a need for a system that can monitor the brush`s length to calculate it`s wear rate, while the component is in operation or without removing of the component from its operational position. We propose a novel method for characterization of carbon brush`s length. This method based on the usage of advantages of the multiplicative response of FBGs and FBG arrays: spectral parameters depend on several aspects, such as grating`s period, refractive index, it`s physical length and so on. We are the first, in our point of view, who proposed to use third parameter for sensing application and prospectively all three parameters for complex measurement: the change of FBG`s length is used to measure length of the brush and it`s wear rate, grating`s central wavelength shift for temperature (due to refractive index change) and mechanical stress (due to grating`s period variations) measurements. The results of modelling and experiments are presented.

This work is concerned with research of Haar wavelet threshold sensitivity for detection of non-reflective events corresponding to optical fiber fusion splices on fragments of fiber optic link traces measured by optical time domain reflectometer (OTDR). We performed test series contained 40 step-by-step repeatable splicing of the same couple of standard singlemode fibers of ITU-T Rec. G.652 spools with length 2.2 km and 4.2 km and outer termination by conventional singlemode FC/UPC pigtails for OTDR connection and following bidirectional trace measurement. Results of insertion loss estimation and accomplished by OTDR software automated detection of non-reflective event corresponding to fusion splice of described optical fibers as well as ability of its visual manual localization on trace were recorded. The first 30 splices were realized by fusion splicer conventional program for jointing standard singlemode optical fibers of ITU-T Rec. ITU-T G.652, while the next 10 splices were done under “attenuator” mode with preset increased insertion loss. Described link traces were measured by OTDR operating in a standard mode with high spatial resolution under pulse width 20 ns and appropriate dynamic range with far-end OSNR 6.5 dB at wavelength 1550 nm. As a result 80 traces were analyzed in both automated and manual modes with fusion splice insertion loss varied from 0.002 dB to 0.554 dB. At the next stage we applied continues Haar wavelet transform for detection non-reflective event on measured traces of lab fiber optic link containing described one fusion splice with total length about 6.4 km. According to results, wavelet transform of described link trace provides detection of extremely low loss non-reflective events with OTDR reading down to own error corresponding to 0.020…0.030 dB range under improved scaling over normalized spatial diagram of wavelet coefficients.

This work presents research results of fiber optic connector ferrule end contamination impact on degradation of key parameters – insertion loss and reflection. We tested four sets of couples of fiber optic connections performed for FC/PC connectors of the same type optical fibers – singlemode (SMF-SMF) and multimode (MMF-MMF) – as well as for differing optical fiber types – SMF-MMF and MMF-SMF. Contamination assessment degree over the connector ferrule end face was estimated by using video probe kit containing video microscope and software which provides ferrule end face quality inspection "PASS/FAIL" according to ratified standard IEC 61300-3-35. The IEC 61300-3-35 standard is a global common set of quality requirements for the surface of ferrule fiber optic connectors. This standard defines 3 zones of ferrule end face: "A" – core zone; "B" – cladding zone; "C" – ferrule zone. Results of direct research of fiber optic connector ferrule end face contamination impact on the insertion loss and reflection are represented.

In this article, the advantages of the unity of sensory and telecommunication approaches will be shown, using examples of monitoring systems for second-generation telecommunication passive optical networks (PON). In comparison with the TDM network architecture, its combination with the WDM architecture is much more efficient, both in terms of the number of channels per fiber, and in terms of the number of channels per laser. This architecture showed a high coverage of monitoring objects by sensors in optically efficient network organization with their small number. Theoretically, the number of sensors in the fiber optical sensor system (FOSS) can be expanded to 256 sensors using two fibers. Note that in the fiber optical telecommunication system (FOTS) the maintenance of 256 PON TDM-WDM terminals is a typical requirement. Thus, monitoring tasks for FOTS and FOSS PON are based on unified approaches. In general, when designing a FOTS, it is necessary to take into account the close relationship that exists between all the factors that determine the characteristics of the network elements, with the existing economic conditions, which will create an optimal network.

Communication cables in general and combined in particular, applied on objects of technological communication of gas, oil, processing industry and also on objects of other industries should have high reliability and resistance to mechanical loadings. This work the resistance of optical fibers and copper conductors of the combined cable to influence of the tensile and crushing loadings and also stiffness of a cable which arise at their installation is considered.

One of the main goals of creating Future Networks is to reduce the energy for their operation through the use of various energy-saving technologies. The most important components of existing and future networks are Passive Optical Networks (PON), which are widely used for building broadband access networks. The methodology for measuring the power consumption of passive optical network equipment with time division multiplexing TDM-PON is discussed in the article. It is based on the materials of ITU-T Recommendations Y.3021 and Y.3022. Estimations of possible energy savings in the GPON network based on OLT and ONU equipment of the Russian company Eltex are obtained with the use of the doze mode and cyclic sleep mode.

In work results of the survey conducted among professional fiber optic technicians and engineers concerned with skills in fiber optic link testing and measurement are presented. Head count was provided on the basis of the Samara Regional Telecommunication Training Centre (SRTTC) of the Povolzhskiy State University of Telecommunications and Informatics (PSUTI) during the period from February to April, 2017. The developed survey included a set of the questions allowing to estimate an work length and qualification of the engineer, his practical skills, the main activity field, typical work volume on measurements and results processing and, respectively, obligatory and optional actions for grouping, marking, structuring and hosting of the database on this or that trace of the elementary cable section of fiber optic transmission links. More than 40 employees of communication industry, business units of the big companies and also the separate enterprises of medium and small business carry on installation and maintenance of fiber optic transmission links have participated in survey. At the same time part of them have been defective, proceeding from the revealed unacceptably low skill level and/or short work length. The analysis of the received survey results have allowed to establish the corresponding subsections of course programs in the "Measurements on Fiber Optic Transmission Links" demanding, at least, enhanced studying, and in some cases – modifications and carrying out an additional lecture practical training.

The article examines modern psychological and pedagogical technologies as a method of development of motivation in training specialists in the field of optical and fiber-optic communication systems. The results of the study of the level of aspiration, socio-psychological attitudes and motivational factors in students are presented, the influence of these components upon the success of solving professional tasks is examined using the method of correlation analysis. The need to develop and implement interactive technologies in the educational process has been studied. The innovative psychological and pedagogical technology of creating motivation of future specialists based on the socio-dramatic plays, trainings is offered.

We present results of experimental research and comparison of differential mode delay (DMD) maps measured for silica graded index multimode optical fibers (MMFs) with strong and weak diameter variation. Preliminary for two synthesized by MCVD fiber preforms were selected by criterion of expected strong DMD due to great profile dip in the core center. Then two lengths of MFMs were drawn. The first one was manufactured according typical operations with automatic control of technological processes, while the second one was drawn under manual maintenance. Therefore two samples of MMFs of ISO/IEC Cat. OM2 with length about 1 km were manufactured with diameter variation ± 0.3 μm and ± 1.2 μm respectively. At the next stage we performed DMD map measurement of described two MMF 50/125 samples by DMD analyzer lab kit R2D2 according to ratified standards TIA-455-220-A/FOTP-220 and IEC 60793-2-10 to research and analyze influence of fiber diameter variation on mode coupling in the form of additional DMD distortions during laser-excited optical pulse propagation over MMF under a few-mode regime.

In this paper, the signal propagation is described by a generalized nonlinear Schrodinger equation take into account linear and nonlinear mode coupling. A modified solution based on split-step Fourier method is considered. The method for simulation of mode coupling coefficients based on statistical characteristics is proposed. Results of bit error rate estimations for space division multiplexing signal propagation in few mode fiber communication line for weak and strong coupling regime are represented.

The technology of frequency coding in channels of quantum key distribution allows to determine the ground state of photons through the value of the amplitude of its carrier, frequency modulated in phase (PM) or amplitude (AM) by a radio-frequency signal, and the resulting side components. Over the past twenty years, it has been substantially modified and improved. At the same time, in recent works, an expanded understanding of the frequency coding principle is used, in which each photon state is associated not with the phase of the modulating signal at a certain frequency, but with one or more sideband frequencies or the carrier frequency of the photon itself. In this paper, we present the results of constructing a frequency coding system of quantum key distribution (QKD) based on the serial electro-optical photon amplitude modulation and phase commutation. The possibility of reducing the probability of achieving a positive result in PNS attacks by Eva is shown by eliminating the carrier of the signal transmitted via the quantum channel from the structure of the key distribution. It was early noted, that the smallest value of QBER is achieved in schemes with a passive definition of one or two basic states of a photon, i.e. without the use of remodulation processes, that is realized in considering. Additionally it is not necessary to form a notch filter system, which is usually carried out using fiber Bragg gratings (FBG) or arrayed waveguide gratings (AWG) for discrimination the photon carrier and its sideband components.

This article is dedicated to interface devices for all-optical synchronization of optical backbone and subscriber line network segments. It is obvious that this type of devices must be all-optical. Due to the importance of phaselock loop (PLL) circuits essential for each telecommunication device an all-optical circuit has been suggested which fundamental principle of operability is in phase cross-modulation effect between tuned and strobe optical signals. Physical parameters of the circuit and time of PLL execution have been calculated. It is shown that this response time is suitable for highspeed devices.

In this article the basic information about the whispering gallery modes (WGM) concerning questions of mathematical description, properties of whispering gallery resonators (WGR), methods of radiation coupling into resonators, resonators manufacture methods, and possible applications in the field of optical communication systems is considered. A brief history of WGM discovery is presented, and the main properties and characteristics of such resonators and modes are discussed. The main goal of this work is to survey the field of WG modes that is becoming more and more attractive due to their interesting and exciting properties with accordance to possible applications in passive optical components development as well as in design of active components such as lasers and modulators.

In this paper we introduce a novel approach for analysis of the information transmission process in mode-divisionmultiplexed (MDM) optical fiber communications. This approach is based on the representation of Maxwell’s equations in the form of quantum-mechanical Schrödinger and Dirac equations. This representation allows application of the welldeveloped quantum electrodynamics formalism for the case of classical EM fields and reveals key properties of the optical fiber mode distribution in MDM systems following from the total angular momentum conservation law. We demonstrate the need of using coupled mode compositions instead of separate eigenmodes for realization of MDM communications based on angular momentum transfer. Such coupled modal compositions obey the law of total angular momentum conservation within spatial transformation and allow information transmission. Spinor propagation equation of EM fields carrying angular orbital momentum in dispersive media is also given.

In this paper we consider nonlinear impairments of mode division multiplexed signals with QAM modulation in optical fibers with linear mode coupling of spatial modes. We simulate simultaneous propagation of fundamental mode and two first-order vortex modes in standard single mode fiber at 850 nm and propagation of fundamental mode and first- and second-order vortices in step-index fiber with enlarged core at 1550 nm. Simulation results shows that in strong coupling regime linear coupling lead to sufficient increasing of nonlinear impairments, but QAM-modulated signal is more robust to this effect than OOK modulated signal.

In this paper, we propose a scheme of a long-lived broadband superefficient multiresonator quantum memory in which a common resonator is connected with an external waveguide and with a system of high-quality miniresonators containing long-lived resonant electron spin ensembles. The scheme with 4 miniresonators has been analyzed in details and it was shown that it is possible to store an input broadband signal field to the electron spin ensembles with quantum efficiency 99.99%. The considered multiresonator system opens the way to elaboration of efficient multiqubit quantum memory devices for superconducting quantum computer.