This PDF file contains the front matter associated with SPIE Proceedings Volume 9156, including the Title Page, Copyright Information, Table of Contents, and the Conference Committee listing.

In the article the algorithm of electronic dispersion compensation of signals transmitted by fiber-optical transmission line (FOL) are reviewed, in the presence of nonlinear effects. The algorithm is based on the use of multi-tier nonlinear phase filters (NPF). In for the solution of the problem is used of unitary characteristics of NPF. Results of modeling and the efficiency analysis of this algorithm by a comparison with the known value of the error rate.

This work presents results of simulation of few-mode optical signal propagation over piece-wise regular multimode fiber link under mode-field matched center-launching (MFMCL) technique. We compared the effectiveness of MFMCL both for the fiber links with conventional OM2/OM3 fibers jointed to fibers for differential mode delay (DMD) compensation and links with low-DMD fibers. According to simulation results, collaborative application of MFMCL and DMD compensation/ reduction techniques will provide bandwidth increasing at least 2.5 times up to several orders in comparison with values of ratified standards.

In this paper we introduce a novel method for mode-coupling compensation in MDM systems based on the adaptive optics. This approach is intended to minimize significantly the computational complexity required for digital signal processing, because only computation of diffraction optical element transmission function is performed and no real time signal processing is required to compensate for intermodal interference. Therefore, existing challenges of MIMO MDM systems, such as DSP performance limits and increasing power consumption, might be overcome.

This paper presents results of investigation on interaction of PMD and Kerr-nonlinearities in long-haul fiber links. It is shown that PMD may significantly reduce impairments caused by nonlinear effects. There are shown dependences on the input polarization, peak pulse power, PMD coefficient and used line codes.

The article explores multiplexers (MUX) and demultiplexers (DEMUX) based on the angular dispersion effect. The article presents calculation of the reflective prism based on MUX-DEMUX CWDM built under the Littrow scheme, as well as the requirements to its optical elements.

Universal method for analyzing optical waveguides with arbitrary non-uniform cross-section is proposed.

We conduct a theoretical and experimental study of the distribution of the electric field components in the focal plane when rotating a zone plate with a π- phase jump placed in the focused beam. By comparison of the theoretical and experimental results, the analysis of the polarization sensitivity of different types of metal-coated aperture probes is conducted. It is demonstrated that with increasing diameter of the non-metal-coated tip part there occurs an essential redistribution of sensitivity in favor of the transverse electric field components and the increase of the probe’s energy throughput. We obtain that the probe response is similar to the transverse component of electric field in the case of Gaussian beam focusing however in the case of Hermite-Gaussian beam focusing the probe response is similar to gradient of electric longitudinal component.

Sharp focusing of homogeneously polarized fiber modes using the binary micro-relief at the output end of the optical fiber is numerically investigated by the FDTD method. The features of the application of sharp focusing for the input of laser modes in the fiber with a smaller diameter are defined.

We study the parameters of micro-relief on the end of the fiber for focusing a linearly polarized Gaussian mode. Such micro -reliefs as refractive lens, diffractive lens, axicon and fractional axicon were considered. It is shown, that diffraction analogy of refractive relief is preferable in some cases for the coupling of waveguides with different diameters.

For any parachute system, it is important to predict the opening forces it will experience in order to make a safe and economic choice of materials to be used. Developed fiber optic sensors on two twisted fibers with the locked ends and variable twisting step have been used for creation of intellectual knots of perspective vehicles, in particular, parachute canopies and slings. We decided to change our measuring procedure from measuring of transmitted power or its Raleigh scattering in different ends of twisted fibers onto Brillouin scattering characterization. For this situation we offered the kind of method of frequency variation to get the information about the frequency shift and Q-factor of the Brillouin scattering in each sensor.

We present model of splice of long optical fibers with precision radial misalignment. It is based on well known overlap integral method and modified Gaussian approximation been generalized on weakly guiding optical fibers with an arbitrary refractive index profile. Power redistribution between mode components of signal during its propagation over optical fiber due to irregularities is simulated by piece-wise regular representation. Results of experimental approbation of proposed model both for singlemode and multimode fibers are presented. A close matching with measured insertion loss dependence on offset is noticed.

In the article it is shown that the birefringence effect is well visualized at the expense of special structure of a laser beam with using Bessel laser beams. On the base of diffraction image variances of Bessel beams on birefringence surface determination of various parameters of a crystal with unknown characteristics is possible.

We introduce solution for linearly polarized guided modes propagating over weakly guiding optical fiber with an arbitrary refractive index profile and constant curvature. Proposed solution is based on well known Gaussian approximation and stratification method.

In this article mathematical models for estimation calculation of birefringence components for step-index optical fiber with a microcrack on the waveguide cladding are considered. Dependences of geometrical and mechanical birefringence components and beat length on the geometrical microcrack size are received. Results of calculation indicate potential possibility of detection of local defects on the waveguide cladding.

The paper deals with the method of a calculation of a dispersion coefficient of an optical fiber, using results of measuring of the refractive index profile of an optical fiber preform. The problem of the parametric synthesis of an optical fiber, using a dispersion characteristic is concerned here.

The approach to selecting modes in complex systems variable multimode models based on expansion of occurring processes in generalized Fourier series on sequentially following time intervals is considered in that paper. It is showing that concerned approach gives opportunity to stabilize parameters and characteristics of radio-electronics and quantum devices with dynamic chaos by complex adaptive influences.

This article is proposed to develop a method of the synthesis of the prediction filter based on the multidimensional linear extrapolation to improve the accuracy of the pixel value prediction, as well as to assess the effectiveness of the proposed predictive filters depending on the prediction step and the dimension of training vectors to minimize the prediction error and the entropy of the differential signal. The article contain a solution of the special cases for a number of elements of the vector prediction, statistical dependence of the vector dimension and prediction filter order from the mean square error and the entropy of the differential signal are determined. Optimal prediction step is founded based on the experimental data and all the results are being analyzed.

Prolate angular spheroidal functions of zero order and their properties has been considered. The calculation of spheroidal functions has been produced for different parameters. One- and two-dimensional Gaussian beam decomposition into spheroidal functions provided in the paper allowed to evaluate the distortion of the optical signal passing through the lens system. We demonstrate the possibility of the formation of the optical signal transmitted through a lens system without distortion as a superposition of spheroidal functions consistent with the parameters of the optical system.

This paper presents novel methods for multiple frequency characterization of stimulated Mandelstam-Brillouin gain spectrum (SMBGS) in single-mode optical fiber. This method is based on the usage of multiple frequencies probing radiation. For conversion of the complex SMBGS from optical to the electrical field single-sideband modulation, direct or heterodyne detection are used. Determining of a multiple frequencies positions over the gain spectrum occurs through the amplitude modulation index of the envelope or the phase difference between envelopes of probing and passing components.

Potentialities of the computational experiment when studying focusing elements for laser light are analyzed. We substantiate the need for the computational experiment when choosing a method for solving ill-posed inverse problems of the diffraction theory and analyzing new types of elements to focus laser light, the feasibility and efficiency of the optical elements under predetermined physical parameters of an optical system.

We have proposed and demonstrated in recent years an unique technique to synthesize the two-frequency radiation by manipulating the amplitude and the phase of initial one-frequency lightwave. The output frequencies are symmetrical relatively to suppressed initial one and have strongly equal amplitudes and alternative phases. In this paper the principle of two-frequency radiation synthesis is summarized. The information structure of two-frequency radiation is examined and key aspects of its application are discussed concerning to the theory of precision spectral characterization of resonant structures and theory of quasi-harmonic oscillations and potential noise immunity.

This paper presents a new two-frequency method for the instantaneous frequency and amplitude measurement of unknown microwave signal. Using the specific interaction of two-frequency radiation with fiber Bragg grating (FBG) in first version and FBG with phase π-shift in second allowed us to obtain measuring characteristics, that are independent of the energy fluctuations of the optical carrier and the microwave signal. Frequency measurement occurs in two ranges: 3-30 GHz in FBG reflection band, and in second version 0,3-3 GHz in the FBG pass band. Additional circuit for spectral characteristics monitoring of the used elements are organized to reduce measurement inaccuracy caused by their temperature instability.

In this article the new method of determination of optical cable stiffness at low temperatures is offered. The method is allows to simplify process of measurements. Thus presence of technicians at climatic chamber in the course of measurements is not required.

The method for measuring of excess fiber length distribution along the cable based on backscattering characteristics measurements by OTDR during climatic tests at both normal and low temperatures is proposed. The results of the method testing are shown in this paper.

This paper presents the algorithm for predictive control implementation on fiber-optic transmission lines. In order to improve the maintenance of fiber optic communication lines, the algorithm prediction uptime optic communication cables have been worked out. It considers the results of scheduled preventive maintenance and database of various works on the track cable line during maintenance.

All modern optical time-domain reflectometers (OTDR) are digital. A peculiarity of a backscatter signal in fiber-optic networks is a wide dynamic range that leads to high demands of a number of digit ADC. Moreover, ADC should be of high speed and low nonlinearity. In this paper we discuss specificity of working ADC in OTDR and the effect of ADC parameters on OTDR features.

This article is presented materials from two tutorials: “Optical two-frequency domain reflectometry^{1, 2}” and “Microwave technologies in industry, living systems and telecommunications³”. These materials were prepared for master training courses and listed in the “SPIE Optical Education Directory” for 2013/2014. The main its theme is microwave photonics. Microwave photonics has been defined as the study of photonic devices operating at microwave frequencies and their application to microwave and optical systems. Its initial rationale was to use the advantages of photonic technologies to provide functions in microwave systems that are very complex or even impossible to carry out directly in the radiofrequency domain. But microwave photonics is also succeeding in incorporating a variety of techniques used in microwave engineering to improve the performance of photonic communication networks and systems. Three parts of this chapter are devoted to applications and construction principles of systems forming microwave photonic filters, measuring instantaneous frequency of microwave heterodyne signals and characterizing stimulated Mandelstam- Brillouin scattering spectrum in ROF systems. The main emphasis is on the use of the two-frequency symmetric radiation, generated by the Il’in-Morozov’s method⁴, in given systems. It is forming radiation for the synthesis of optical filters coefficients, it’s application and processing determine the increase in the signal-to-noise ratio during heterodyne frequencies monitoring and characterization of nonlinear effects spectrum.