Showing papers by "Anton V. Bourdine published in 2015"

Modeling and simulation of a few-mode long-haul fiber optic transmission link

Abstract: Based on coupled nonlinear Schrodinger equation (CNLSE) piecewise regular model of few-mode long-haul fiber optic transmission link with DWDM and Erbium amplifiers is considered The few-mode fiber optic transmission link model takes into account the loss, dispersion, differential mode delay, nonlinearity and non-regularity Based on mode coupling theory and Gaussian approximation modification of split-step Fourier method for the numerical simulation of the CNLSE is introduced Examples of simulation of a few-mode long-haul fiber optic transmission link by this method are presented

Research of potentiality of nonlinear effects mitigation by considerable increasing of optical fiber core diameter

Abstract: In this paper the potentiality of nonlinear effects mitigation by increasing of optical fiber core diameter was investigated. The numerical simulation of return to zero differential quadrature phase shift keying optical signals propagation taking into account nonlinear effects was performed. As result the Q-factor dependence from effective mode diameter was obtained for different signal parameters. The results of optical fiber synthesis with given parameters are represented.

Method for computing the equivalent graded refractive index profile of silica multimode optical fibers via differential mode delay diagram

Abstract: This work presents method for computing the equivalent graded refractive index profile of multimode optical fibers via differential mode delay diagram reconstructed by few-mode pulse response at the receiver end of researched fiber. Equivalent refractive index profiles for commercial multimode fibers of Cat. OM2 with central defects as peak and dip were computed. Results of proposed method approbation are represented.

Fast and Simple Method for Evaluation of Polarization Correction to Propagation Constant of Arbitrary Order Guided Modes in Optical Fibers with Arbitrary Refractive Index Profile

Abstract: This work presents fast and simple method for evaluation of polarization correction to scalar propagation constant of arbitrary order guided modes propagating over weakly guiding optical fibers. Proposed solution is based on earlier on developed modified Gaussian approximation extended for analysis of weakly guiding optical fibers with arbitrary refractive index profile in the core region bounded by single solid outer cladding. Some results are presented that illustrate the decreasing of computational error during the estimation of propagation constant when polarization corrections are taken into account. Analytical expressions for the first and second derivatives of polarization correction are derived and presented.

Direct method of determination of the equivalent refractive index profile of the multimode optical fiber by measured impulse responses due to scanning output fiber end

Abstract: This paper demonstrates the possibility of determining the equivalent, in terms of the coincidence of differential mode delay diagram, refractive index profile of the multimode optical fiber by direct method and responses to pulse action, which are measured at the output through single-mode optical fiber. As an example, by using the measured data of the refractive index profile of the sample of multimode optical fiber and based on Gaussian approximation model impulse responses at the output of a short length single mode fiber, which was jointed with multimode fiber, were calculated. Multimode and single mode fibers were jointed with axial misalignment. Responses to impulse action were calculated for several values of axial misalignment of single-mode and multimode fiber. From the responses by the direct method the equivalent refractive index profile was determined. Comparison of the results of calculations of the differential-mode delay diagram for the investigated and the equivalent refractive index profiles showed their good agreement.

Solution for circular lightguide based on Gaussian approximation with correction of mode field distributions into cladding

Abstract: This work presents modification of Gaussian approximation. Here we propose to describe mode field distribution in fiber core by Laguerre-Gaussian functions and by modified Bessel function of the second kind in the fiber cladding. Results of error estimation are presented for equivalent mode field radius calculation occurring due to mode field distribution approximation by Laguerre-Gaussian functions in the cladding region. According to obtained results the error is negligible for low-order modes. However it increases up to 1% and even more for modes with (m + l) > 4, where m is radial and l is azimuthal mode order.