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Fiber Birefringence Modeling for Polarization Mode Dispersion

by Huang, Weihong

Abstract (Summary)
This thesis concerns polarization mode dispersion (PMD) in optical

fiber communications. Specifically, we study fiber birefringence,

PMD stochastic properties, PMD mitigation and the interaction of

fiber birefringence and fiber nonlinearity.

Fiber birefringence is the physical origin of polarization mode

dispersion. Current models of birefringence in optical fibers assume

that the birefringence vector varies randomly either in orientation

with a fixed magnitude or simultaneously in both magnitude and

direction. These models are applicable only to certain birefringence

profiles. For a broader range of birefringence profiles, we propose

and investigate four general models in which the stochastically

varying amplitude is restricted to a limited range. In addition,

mathematical algorithms are introduced for the numerical

implementation of these models. To investigate polarization mode

dispersion, we first apply these models to single mode fibers. In

particular, two existing models and our four more general models are

employed for the evolution of optical fiber birefringence with

longitudinal distance to analyze, both theoretically and

numerically, the behavior of the polarization mode dispersion. We

find that while the probability distribution function of the

differential group delay (DGD) varies along the fiber length as in

existing models, the dependence of the mean DGD on fiber length

differs noticeably from earlier predictions.

Fiber spinning reduces polarization mode dispersion effects in

optical fibers. Since relatively few studies have been performed of

the dependence of the reduction factor on the strength of random

background birefringence fluctuations, we here apply a general

birefringence model to sinusoidal spun fibers. We find that while,

as expected, the phase matching condition is not affected by random

perturbations, the degree of PMD reduction as well as the

probability distribution function of the DGD are both influenced by

the random components of the birefringence. Together with other

researchers, I have also examined a series of experimentally

realizable procedures to compensate for PMD in optical fiber

systems. This work demonstrates that a symmetric ordering of

compensator elements combined with Taylor and Chebyshev

approximations to the transfer matrix for the light polarization in

optical fibers can significantly widen the compensation bandwidth.

In the last part of the thesis, we applied the Manakov-PMD equation

and a general model of fiber birefringence to investigate pulse

distortion induced by the interaction of fiber birefringence and

fiber nonlinearity. We find that the effect of nonlinearity on the

pulse distortion differs markedly with the birefringence profile.

Bibliographical Information:

Advisor:

School:University of Waterloo

School Location:Canada - Ontario

Source Type:Master's Thesis

Keywords:optical fibers birefringence polarization mode dispersion physics

ISBN:

Date of Publication:01/01/2007

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