In this paper noise performance of Raman amplifiers is analyzed. Efficient model and methods for calculation of noises impact in Raman amplifier of various designs (forward, backward and bidirectional pump schemes) are presented. Developed models are taking into account features of not uniform amplifier span and cascaded amplifier spans. An analytical solution for ASE noise allows to reduce time expenses at simulations. Analytical and simplified expressions for DRB noise can be used to investigate qualitative dependence from different factors. Area of application developed models was defined as distributed Raman amplifier with standard single mode fiber.

This document describes our research in the area of resource parameters of optical fiber used in the method that we suggest for remote pumping of EDFA amplifier. Unlike the traditional method, our method 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 placed. In conclusion, some areas of our current research are discussed.

Proposed information technology for remotely sensed data processing is based on anomaly detection methods and algorithms, which are invariant to signal and background scale and structure, is advancement of existing approaches. The information technology combines the following conceptions and approaches: satellite images fractal self-similarity; multiresolution analysis of functional spaces on the base of wavelet transform (WT); using recursive fractal scanning for reduction of multidimensional spaces into one-dimensional segment; using nonparametric statistics for signal detection in noisy background. Proposed technology allows to: decrease the threshold of hidden signal detection by several times; detect the signals with unknown form; solve the problems connected to incomplete knowledge of signal, nonstationary, non-markovian and singular noises; improve the performance of subpixel signal detection and estimation in case of limited spatial and temporal resolutions of sensors. The investigation of Hausdorf dimension and index of Hoerst statistic is performed. Solution of the following problems is planned as extension of this research: conjugation between WT and recursive scannings for obtaining the powerful signal analysis mathematics, development of S/N ratio increase methods on the base of statistical image segmentation using nonparametric statistics; improvement of accuracy of subpixel signal estimation on the base of using the fractal properties of images.

The present article is devoted to research of an opportunity of optical signals switchboards creation controlled in addition by submitted optical radiation. It is supposed, that the managing radiation changes a parameter of refraction of optical environment of the device, and with it and length of a wave of information radiation. For the control by last is used multibeam interferometer. The brief estimation of technical aspects of construction of the device is carried out. The analysis has shown that the interferention switchboard essentially technically is sold. To basic its lacks it is possible to attribute presence constant making in to an interferention picture and distortion by action interference and nonlinear optical effects of a digital optical signal.

It considered using non-linear phase filters for compensation of a dispersion of optical signals on an electric level of a fiber-optic transmission lines. The questions of optimization of these filters with the check of change form of a bending around of optical impulses are discussed.

The problems concerning reliability connections of optical cables in closures are considered. Drew conclusions on necessity of completion of normative base existing today, develop technological cards of installation closures in view of features such as a cable for which it is used closure, include in techniques of certified tests closures for an optical cable the control of parameters of transfer of optical fibers in closures.

In the given work method of the approached calculation of the dispersion slopes for single-mode fibres with an arbitrary coaxial refractive index profile is described. Research of errors of the known approached calculation methods -modified Gaussian method and approximation for small values of the normalized frequency is executed. The formula for calculation waveguide parameter and its derivatives in all range of the normalized frequencies is offered. The estimation of adequacy for application of the method is carried out.

In this paper the spectral characteristics of Rayleigh scattering parameters were considered for different types of single-mode fibers. Making use of Gauss approximation mode field, I have proposed analytical equations for scattering parameters. Using these equations spectral characteristics of scattering parameters are calculated for the most used types of single-mode fibers. Results of calculations were compared and analyzed.

While designing the extended fiber-optic communication lines, designers have a serious problem consisting of large financial investments. The use of the EDFA amplifiers solves this problem but there is another one. The matter is while using the EDFA amplifiers, all necessary equipment for pumping is to be set in the zone of amplification. This equipment consists of the pumping laser working at the wave length of 980 nanometers i.e. that is for the work the place should be provided by power supply. For the decision of the given problem the use of a remote pumping way is offered. For a technical realization of the given method, the article describes the method of fibers creation with multistage index profile which can be used for supplying the informational and pumping signals in one fiber. Also the article contains the method which allows making a joint of different type fibers both in mode structure and with different geometrical sizes.

The weakly guiding approximation is the basis for the most well-known methods and their extensions for evaluation of optical waveguide parameters. However, solutions of scalar wave equations are not exact, and there are some applications requiring more high accuracy. It is obviously, polarization effects, occurred by guiding properties of the optical fibers, must be taken into account to improve the accuracy. Thus, "polarization correction" term, described by A. Snyder, must be added to scalar propagation constant. Method, based on Gaussian approximation, for calculation of polarization correction to the any order mode propagation constant in weakly guiding optical fiber with an arbitrary coaxial index profile is proposed. Results of error reducing by adding of correction to propagation constant, obtained by scalar wave analysis, are demonstrated. First and second order derivatives of the correction are obtained and represented.

The problem of the minimax recovery of a nonparametric two-dimensional signal blurred by some khown function and observed with additive noise is considered. The unknown function of two variables is assumed to belong to a hyperrectangle of L₂([0,1]²) Under some conditions, we find the exact asymptotic behavior of the quadratic minimax risk. We propose linear minimax estimator and show that its maximal risk attains asymptotically the minimax risk. In the case of non-Gaussian noise we propose other estimator that however is not asymptotically optimal.

Using Data series is of great importance when examining processes of different nature. In the article some nontraditional methods of dependence analysis, tendencies approximation and forecasting techniques based on Data normalization are represented.

For reliable teamwork of various systems of automatic telecommunication including transferring systems of optical communication networks it is necessary authentic recognition of signals for one- or two-frequency service signal system. The analysis of time parameters of an accepted signal allows increasing reliability of detection and recognition of the service signal system on a background of speech.

The paper analyses present reflectometry systems for their application in optical fiber structures monitoring. The method of optical reflectometry for OFS monitoring in two frequency domain (OTFDR) is considered. Systems on the base of two-frequency probing for studying Raman and Brillouin scattering and parameters of FBGs are proposed. Questions of OTFDR application efficiency for these applications are discussed.

Optical time domain reflectometer (OTDR), based on Rayleigh backscattering time domain method, is one of the basic measurement instrument for optical fiber link parameters determination. However, OTDR provides only an indirect measurements that allows to additional errors. Analysis and evaluation of errors, occurring during fiber optic link attenuation measurements by Rayleigh backscattering time domain method are proposed. Results of experimental investigations of the error of quasi-regular section attenuation measurement, depending on signal-to-noise ratio and section length are represented. Recommendations to OTDR operating mode selections are defined.

The analysis of traditional ways application of measurement on a direct current for search damage location of optical fiber cables of communication has shown the following. Considered ways of measurements are intended for definition of a zone of damages, for the subsequent localization of damage by line-search devices. As consequence, from them is not required high accuracy of estimations. It allows recommending the simplified methods with a margin error up to 10%. Simple bridge and bilateral methods of measurements on a direct current allow receiving estimations with a required error. Approbation of recommended methods has yielded positive results.

Polarization mode dispersion is a very important parameter controlled on a fiber optical transmitting lines. PMD researches of optical fibers on the cable lines which have been handed over in operation, have shown, that its resulting value on a reclaiming part frequently is defined be relative by a small number of lengths with raised values PMD. it is important to have means of measurements allowing to investigate propagation PMD in optic fiber and to locate parts with high values of a dispersion. This problem solve optical reflectometr for measurement PMD P-OTDR.

At increase in a link speed of the data on a fiber optic network up to 40 Gbits with and is higher, influence Polarization modal dispersion (PMD) increases. Measurements on building lengths were spent, at change of climatic conditions. The purpose was to reveal influence change ofa climate on PMD in a cable and closure. Tests on a cable with closure and separately on closures were spent. Schedules of change PMD from temperature were under construction.