SATNAC 2007 Conference Papers

Optical, Transport & Core Networks

Title:                   Investigation of the Fixed Analyzer Technique for Polarization Mode Dispersion Measurements on Optical Fibres

Authors:              Romeo Gamatham (Nelson Mandela Metropolitan University),
Tim Gibbon (Nelson Mandela Metropolitan University), Lorinda Wu (Nelson Mandela Metropolitan University), Andrew Leitch (Nelson Mandela Metropolitan University)

Abstract:             In this paper the fixed analyzer technique is employed to measure the polarization mode dispersion (PMD) of several different types of optical fibre. The data was analyzed using the extrema counting and mean-level crossing methods. Comparative PMD measurements were done using the Jones matrix eigenanalysis (JME) and interferometric PMD measurement techniques. The fixed analyzer PMD measurement results compared well with the PMD determined by the JME and interferometric techniques. It was however shown from error plots that the extrema counting analysis method has some limitations regarding its accuracy. A comparison between the extrema counting and mean-level crossing analysis methods are shown to agree well with one another. The bias in fixed analyzer measurements due to incorrect sampling is also briefly investigated and shown to be important in obtaining accurate results.

 

Title:                   PMD Measurements on Undeployed and Deployed Aerial Optical Fibre Cables using the Interferometric Technique

Authors:              Azwitamisi Mudau (Nelson Mandela Metropolitan University),
Lorinda Wu (Nelson Mandela Metropolitan University), Timothy Gibbon (Nelson Mandela Metropolitan University), Andrew Leitch (Nelson Mandela Metropolitan University)

Abstract:             Polarization mode dispersion (PMD) is one of the major factors limiting high data transmission rates (10 Gb/s and above) in optical transmission systems. PMD originates from birefringence and mode coupling and is affected by the environment where the optical fibre cable is deployed. In this study, PMD was measured on undeployed and deployed aerial optical fibre cables using the interferometry based PMD analyzer. The effect of environmental conditions (temperature and wind speed) on PMD was investigated on the deployed aerial cable. We found that the PMD fluctuates more rapidly on deployed aerial cable than on undeployed cable, because of the faster changes on environmental condition. On the other hand, the PMD of the deployed aerial cable measured without polarization scrambling showed significant correlation with its environment, namely a change in the temperature and the wind speed.

 

Title:                   Impact of Cross-talk on Polarization Mode Dispersion Compensators

Authors:              David Waswa (Nelson Mandela Metropolitan University),
Tim Gibbon (Nelson Mandela Metropolitan University), Lorinda Wu (Nelson Mandela Metropolitan University), Andrew Leitch (Nelson Mandela Metropolitan University)

Abstract:             We demonstrate both experimentally and by simulation nonlinearity-induced depolarization in wavelength-division multiplexing, in which the Stokes vector of each channel rotates around a space-invariant pivot by a time varying angle. The rotation depends on the total instantaneous optical power in the fibre, the angle between the pump and probe, and the channel spacing. These are identified by simulation as the key factors that determine the nonlinear-induced performance degradation on polarization mode dispersion compensators. They are validated by experiments.

 

Title:                   Frequency Domain Chraracterization of an Experimental and Simulated Polarization Mode Dispersion Emulator Design

Authors:              Selma Younsi (Higher School of Communication of Tunis),
Vitalis Musara (Nelson Mandela Metropolitan University), Timothy Gibbon (Nelson Mandela Metropolitan University), Lorinda Wu (Nelson Mandela Metropolitan University), Mourad Zghal (Higher School of Communication of Tunis), Andrew Leitch Nelson Mandela Metropolitan University

Abstract:             Polarization mode dispersion (PMD) emulation is a vital approach in addressing and analytically investigating the deleterious statistical nature of PMD in optical network fibre links under a controlled laboratory environment. The authors propose an optimal design of an experimental PMD emulator validated through a simulation design. This investigation examines the impact of the number of birefringent sections and orientation of the mode coupling angles in an emulator, and their statistical distributions. Analyses over a large band of optical frequencies and validation of the emulator through statistical studies have been achieved. Emulator stability and repeatability of the experimental design has been examined through state of polarization monitoring.

 

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