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``Comparison of the Jones matrix analytical models applied to optical systems with high-order PMD''
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Comparative study among analytical and numerical models for the performance evaluation of optical systems affected by polarization mode dispersion
No full textA Simple and Useful Model for Jones Matrix to Evaluate Higher Order Polarization Mode Dispersion Effects
No full textStarting from the differential equation that relatesthe Jones matrix of a polarization-mode dipersion (PMD) fiber toits output dispersion vector, the analytical expressions of the matrixcoefficients are determined in the case of a dispersion vectorrotating on a circonference in the Stokes space. This model, thatneeds only few parameters with known statistics, is applied to evaluatethe performance of an optical system. The results obtainedwith it and with other models proposed in literature are comparedto those evaluated by numerical simulations with all-order PMDeffects, showing that our model gives an accurate representation ofreal system performances
Jones Transfer Matrix for Polarization Mode Dispersion Fibers
No full textWith the advent of long distance high bit rate optical systems, polarization mode dispersion (PMD) has become an important source of limitation for the system performance. In a first order approximation, PMD, that is described by a differential group delay (DGD) between two orthogonal states of polarization (PSPs), causes an undesired output pulse broadening; the frequency dependence of DGD and PSPs produces other distorting effects, considered as higher order PMD effects. A useful theoretical means of predicting the overall distortion of the transmitted signal is the evaluation of the Jones transfer matrix of the fiber but, unfortunately, the statistics of its coefficients are not available up to now. On the other hand, the statistical behavior of the three-dimensional dispersion vector, that characterizes the PMD of the fiber in the Stokes space and can be measured, is known up to a second order PMD approximation. Consequently, finding the analytical relationship between the PMD vector and the coefficients of the Jones matrix is mandatory. In the work, the tight methodology of calculating the Jones matrix, starting from the knowledge of the PMD vector, is shown. This new method is used to determine the output temporal pulse expression in a second order PMD approximation and it is applied to evaluate the performance of a system affected by PMD. The results obtained with the present model are compared to the performance evaluated by numerical simulations, where all order PMD effects are taken into account; our model gives a performance curve that is more accurate in the approximation of all order PMD effect
Analytical evaluation of optical system impairments caused by high-order polarization-mode dispersion effects
No full textThe differential equation that relates the Jones matrix of a polarization-mode dispersion fiber to its output dispersion vector is solved for a dispersion vector that moves on a circumference in the Stokes space, It yields a new simple model that can be usefully exploited to calculate the pulse-broadening analytical expression and to evaluate the system performance in terms of outage probability. A comparison among the results obtained with it, with other models proposed in literature, and with the numerical DRW model show its best accuracy
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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