An increase in the data-carrying abilities of modern communication systems is a most important scientific and technical challenge, requiring further studies of the physical effects involved. The possibility to increase in the data-carrying abilities of optical communication systems by waveguide transverse modes multiplexing by diffractive optical elements (DOEs) is considered.

The criteria method of inverse optimal filtration for additive secondary hidden channels characteristics synthesis is proposed. The additive channel is destined for telecommunication channel capacity increasing and transmits of controlling, signaling and protected information. Also the inverse method of optimal filtration is extended for multiply connected optical telecommunication system. For decreasing influence of the primary and secondary signals on each other is presented two criterions in article. The first criterion describes degree of distortions in primary channel and is define as vector inequality; the second criterion evaluates degree of renewal process in secondary channel and is presented in functional form. The example was adduced for illustration of proposal hidden spectral characteristics synthesis for optical telecommunication system.

In this paper features of broad-band Raman amplifier design and simulation was considered. Numerical and analytic approaches for Raman amplifier simulation was represented. Such effects as pump-to-pump interaction, signal-to-signal interaction, pump depletion was taking into account. Raman amplifier model take into account any pump direction and arbitrary number of pump sources. Simulation of WDM signal propagation in optical fiber line take into account dispersion, nonlinear effects, and also influence ofdistributed Raman amplification.

This document analyzes the existing techniques of acquiring high power 980 nm laser radiation, which is required for pumping erbium-doped fiber amplifier (EDFA) in developed by us method of connecting it to fiber-optic communication line (FOCL). Unlike the traditional method, this new one lies in transferring the information signal and pump radiation in common single-mode optical fiber, which provides the opportunity to remove the electrical components from the zone, where the amplifier is situated. We review the advantages and disadvantages of every technique, as well as consider the perspective technologies, wide application of which is expected in the near future. Also, suggestions on usage of alternative pump impulse sources are offered and some results of our current research are discussed.

The use of fused and mechanical splices in optical lines induces multipath interference at transmission of signal which induces because multiple reflectance from splices and connectors. The effect of multipath interference can influence general reflection parameters of optical fiber line and reduce receiving signal. In this paper simulation of multipath interference in optical line with multiple reflectances and its influence on the general reflection parameters is considered.

Nowadays there are several problems, limiting realization of the systems of automatic control based on fiber optic technical equipment. First of all it is the specific feature of signals transmitted with possible condensation (analog signals). Second is caused by the absence of components, adapting to influence condition, like vibrations, acoustic noise, temperature fluctuations. Here we compared two systems, developed for telecommunications: with signal condensation and without signal condensation. Complication is still connected and that is necessary fast (in a mode of real time) processing of a signal. The result of processing should be transferred with use of same system of telecommunications to the devices providing management by modes ofthe engine. Besides the system should be reliable and have reserve ways. In given article statement of a problem is submitted and ways of its decision are proposed.

Method for pulse distortion simulation during propagation along multimode fiber optic transmission link under guided mode excitation by the singlemode laser source is proposed. Launch conditions, the defect of real graded profile of conventional multimode fiber and fluctuations of guided mode group velocity are taken into account. Been obtained by proposed method, there are results of computation of pulse response at the mutimode fiber link output under transmission optical signal, generated by laser source of singlemode fiber optic telecommunication system STM-4. Different launch conditions (type of singlemode conjugating fiber, launch misalignments) and their influence on pulse distortion were investigated.

In letter the individual task solved within the framework of a common problem of the analysis of composite waveguide system, containing generally cascade connections of delguides with different parameters (as immediate, and through irregular ganging transitions) is considered. At solution the technique based on finite-difference approximating of second-kind equations with preliminary definition of amplitude-phase allocation of equivalent sources by methods of physical optics will be utilized effective, in sense computing time.

In the given work results of the theoretical analysis of errors of the approximated calculation methods for transfer parameters of weakly guiding single-mode optical fibres are submitted, namely a Gaussian approximation method and approach for small values of the normalized frequency. Errors were defined by testing for a modeling step refractive index profile of weakly guiding optical fibre for which a strict decision is exist. As a result of differentiation of the known characteristic equation for a step optical fibre analytical expressions for the first and second derivatives of a square waveguide parameter U² and, accordingly, derivatives of a distribution constant of a waveguide have been received. Calculations of dependences of a square waveguide parameter U² a distribution constant for a basic mode of a step fibre and their derivatives from the normalized frequency for area of small values V, great values V and area of changes V near to unit are executed. Calculations were made both on the basis ofthe strict approach, and on the basis of the approximated solutions. In result dependences of errors of the approximated solutions are received depending on the normalized frequency, allowable scopes for considered approximation are determined.

At the solution of a problem of synthesis of refractive index profile of optical fibres with the set dispersive characteristics by optimization methods it is important at formation of initial conditions with the maximal accuracy to come nearer to a global minimum. It demands preliminary research of dependences of chromatic dispersion slopes from parameters of refractive index profile ofan optical fibre. In the given job results of theoretical researches of chromatic dispersion slopes, its parameters (wavelength of zero dispersion, an inclination of the spectral characteristic) are submitted depending on core radius and profile height. For calculations of dispersion the known analytical expressions received on the basis of the modified Gaussian approximation method were used. Calculations have been executed for single-mode optical fibres with a step, triangular and parabolic refractive index profile in a working range of wavelengths of CWDM systems. The received results allow to predict tendencies of chromatic dispersion changes, give quantitative ratings of its spectral characteristics changes depending on the form and parameters ofrefractive index profile of an optical fibre.

This document describes a number of results of our research in the area of implementing pulse lasers as pump sources for erbium-doped fiber amplifiers (EDFA). The aspects considered in this document include the effects of impulse pumping signal on information signal. In addition, the desired parameters of pulse pump laser, that provide the given level of error probability, are listed. Also, the overall estimates of resource parameters are provided and other important issues are discussed. In conclusion, some areas ofour current research are discussed.

We present an extension of the modified Gaussian approximation method to analyze multimode optical fiber with arbitrary axial-symmetric refractive index profile. Unlike to known Gaussian approximation, optical fiber with an arbitrary index profile is considered as multi-cladding optical waveguide, and core region profile is represented as the set of N layers in which the refractive index can be taken as a constant. Numerical values of the core mode parameter and propagation constant were obtained and compared with exact solutions. In all cases, good accuracy was noticed.

Last decade the big notice ofthe technicians engaged in creation and probing ofnew materials, physicists, mechanics has caused nanostructural materials. These materials have unique structure and properties, many of which have direct practical interest. In nanostructural materials are often changed fundamental, usually structural-tolerant characteristics, such as elastic modules, temperatures of Kury and Debay, magnetization of saturation, etc. It allows to improve existing and creation of essentially new constructional and functional materials, which are possible to design of all-optical network componets. Nanostructural materials belong crystal materials with the average size of grains or other structural units, less than I 00 nanometers. There are various kinds of such materials. By geometrical attributes it is possible to divide them on nuclear clusters and particles, one and two-dimensional multilayers, coverings and laminar structures, three-dimensional volumetric nanocrystalic and nanophase materials. Here we proposed an application of nanostructural materials for design of all-optical network components. Results of Kury temperature variation, Pockels effect and Kerr effect and other properties are presented.

Optically transparent nanostructural materials show to themselves a heightened interest owing to display in them the new physic mechanical properties. Variation of structure of the materials received by methods of intensive plastic deformation, results in variation of many fundamental parameters. Among them special interest was caused with variations of fundamental magnetic characteristics. One of them is the magnetization of saturation, which is usually structurally tolerant, but reflects changes in an atomic-crystal structure of solids. Even in the first probing of the transparent nanostructures, received by intensive deformation by torsion of samples, was found that the magnetization of saturation was revealed at room temperature in comparison with coarse-grained samples. High-power measuring devices are based on Faraday effect, representing itself rotation of a plane of polarization of linearly polarized light in optical active substances under action of a magnetic field. Application of nanostructural materials in the optical insulator, which is the main part of the measuring device, allows improving the measuring characteristics of instruments qualitatively. Brought losses in Faraday cell make 0,35 -0,89 dB instead of 0,7 - I,2 dB, and value of the backward losses makes not less than 62 dB instead of 55 dB. Undoubtedly, improvement of the given parameters allows making the measuring operations with the greater accuracy, reducing both absolute, and relative errors.

The present paper is devoted to probing of a possibility of application of the transparent nanostructure quartz at build-up of components of all-optical networks. Nanostructure photos are obtained and diagrams of allocation of grains on the reference sizes built. Measurements of stimulated Mandelshtam-Brillouin (SSMB) scattering in such samples are carried out. It is established, that there is build-down SSMB on 7...10%. The analysis of distortions of a digital signal is theoretically carried theoretically out by action of nonlinear and dispersion optical effects on the part of managing radiation. The theoretical estimation of importance of transmission rate and reflectivity of mirrors of the interference device of management in which limits dispersion distortions will stay in the frames installed by the specifications and tecimical documentation is carried out.

Usage of diffractive optical elements (DOEs) in fiber sensors is rather promising. This work is dedicated to the investigation of dependence of transverse mode spectrum in fibers with the step-like refractive profile on the micro bending value by means of the diffractive optical elements. Description of an experimental setup is provided here as well as methods of the experimental data processing allowing to have accurate measurements of the mode power. Dependence ofthe LP mode power on the fiber micro bending value is received. The received results allow expecting to design fiber sensors with advanced characteristics-dynamic range and accuracy.

Results of numerical simulation of automatic tracking algorithms for the free space optic (FSO) laser bundle spreading in a turbulent atmosphere from the transmitter of one subscriber to the transducer of other subscriber are presented. A model of the system and a simulation program are created and different adaptive correction algorithms are analyzed. It is shown that the character of an algorithm and its parameters significantly affect the system behavior. The results of numerical study have been obtained for a 1-beam laser.

Hybrid optoelectronic landmark navigation is proposed as backup navigation for Low Earth Orbit satellite. Optoelectronic navigation can use earth observation camera, originally not assigned for navigation purposes. The concept of the landmark navigation system is based on the onboard optical correlator application for real time matching of the earth images and pre-recorded images of landmarks with known coordinates. The software model of image processing by optical correlator has been developed to test the system operation in simulated experiments and to estimate the expected performance. The hardware model of the joint transform optical correlator has been manufactured and tested. The model uses commercially available optoelectronic components and works with PC, which performs all digital processing and data flow control. As a result ofthe model testing, the feasibility ofthe system concept and the adequacy ofthe software model have been proved. The image processing system which calculates satellite attitude and position on the base of correlation peaks measurements has been used for simulation of optoelectronic satellite landmark navigation. In the series of simulated experiments the navigation accuracy was estimated in presence of image distortions and noise for earth observation mission.

Practical realization of any computerized Optical Multichannel Spectra Analyzer (OMA) implies that rather sophisticated software must be developed to process the data obtained from AD converter, connected to the optical detector (usually based on linear CCD or an array of photo diodes). Neural network (NN) may be regarded as a modern and beneficial alternative to that common approach, because NN is traditionally considered as a good instrument to solve the problems of Pattern Recognition and Signal Analysis. Unfortunately all the necessary parameters for neural network setup could not be easily calculated in a formal way. Besides, most of the OMA-type units are supplied with the detectors containing many hundreds of diode cells to gain high spectral (or spatial) resolution. It means that a NN under consideration must be able to process a great deal of inputs. The problem ofNN design is additionally complicated by the necessity to keep its functionality under condition of various time dependent discrepancies, drifts, noise etc. Some approaches to the practical realization ofNN-based OMA and results achieved are presented.

Quantitative estimation of a level of interference distortions was carried out through the replacement of real trapezoidal signals by the model harmonious signal. Analytical expressions for amplitudes of the first and the maximum harmonics were obtained. Influence of a skew of mirrors on resulting signal in Fabry-Perot interferometer (FPI) was investigated. Distortions were represented by the pulse form variation and increasing of bit-error probability. The spectral analysis ofreceived signal has allowed to estimate the relation between the signal level and distortion level. It is well known, the skew of interferometer mirrors is the most influence factor. Transfer interferometer characteristics was obtained, and its properties were investigated.

The paper represents approbation of the education manual structure, based on wide experience of open and built-in reflectometric systems development and creation on Department of Radio-Electronic and Quantum Devices and in the Research Center of Applied Electrodynamics of the Tupolev Kazan State Technical University with active assistance of the Ministry of Communications of Republic Tatarstan, State Unitary Enterprise FSPC <> and the Kazan branch of the International Telecommunication Academy.

The paper defines current importance of scientific and technical problem of metrological characteristics improvement and functionalities expansion of optical fiber structure (OFS) monitoring systems on the base of two frequency probing. Analysis and synthesis problems which should be solved by development of the theory and technical equipment of optical reflectometers for OFS monitoring in two frequency domain (OTFDR) are considered. Questions of OTFDR application efficiency for OFS monitoring on the examples of OTDR with two frequencies filling of probing pulse, non coherent OTFDR with LFM modulated components, and two frequencies heterodyne for SCF-OFDR are examined.

Hard electro-magnetic (EM) impulse influence over optical cables is considered. This problem is typical for optical cables with metallic constructive elements. In such cables there can be electrodynamic destruction factors. EM influence sources, means and mechanisms are considered. The necessity of optical cable (OC) EM safety technical inspection on fiber-optic transmission line (FOTL) linear-cable construction is shown. The choice of analytical methods of EM conditions and complex appraisal ofconnection objects EM compatibility is done.

It has been shown that fiber-optic transmission line (FOTL) quality and reliability are mostly determined with the firmness of optic cable (OC) with metallic elements against outward electro-magnetic (EM) influence. The most important questions are quality control ofprojection and construction ofFOTL linear-cable structure, and also realization of prophylactic work at FOTL exploitation stage. The questions of OC external covers characteristics control and condition control ofFOTL linear-cable construction system ofprotection from lightning and EM influence are shown.

Efficiency of concept category application in research methodology of radio-electronic and telecommunication systems was experimentally explored. it was experimentally proved that procedure of concept category determination by the algorithm for revealing of the general attributes of objects examined can ensure the high efficiency of explorations both in science disciplines corresponding to professional sphere of investigator and disciplines which are considerably distant from this sphere. Considered methodology contribution into the final results of researches can reach the value up to 100%. Concept category application makes it possible to transfer the results evaluation from the sphere of new disciplines into the sphere of initial science discipline, in the congruent axiology system. Concept category application facilitates both development of various disciplines and changes their boundaries resulting in mutual penetration of these disciplines, too. Based on fulfilled explorations the dictionaries of fundamentally new type, more specifically, phonetic bilingual dictionaries for radio engineering and telecommunication terms were developed. The area of current patent laws was corrected. As a result a new class of industrial property objects (dictionaries) was revealed and minor patents on the dictionary of foreign language were first received. Representation of the radio and telecommunication signals as industrial property objects was founded.