Polarization mode dispersion PMD becomes the most limiting factors for achieving high-speed optical transmission. The size of the dierencial group delay between the polarization plane is influenced by many different factors and therefore accurate measurement of PMD should be done in all phases of building and operating optical path.

This diploma thesis is focused on use of polarization mode dispersion for measurement of temperature. It also deals with representation of polarization mode dispersion in Poincaré sphere and a mathematical description of polarization mode dispersion by using Stokes and Jones vectors. Here are described basic alternatives of settings, selected temperature relationships and dependence and relationship between coherency and polarization. The practical portion of the diploma thesis examines behavior of the temperature sensor at different temperatures for wavelength 1550 nm and 633 nm.

[pt] Este trabalho apresenta o estudo e a realização de experimentos a fim de investigar os efeitos da PMD (Polarization Mode Dispersion) no controle de polarização implementado em um enlace de fibra óptica monomodo. Esse estudo permitirá a otimização de controladores de polarização em sistemas de transmissão que venham a utilizar multiplexação em polarização (PolMux) combinado a técnicas de UDWDM (Ultra Dense Wavelength Division Multiplexing), possibilitando o aumento da taxa de transmissão em um canal. Para tanto, foram realizadas medidas experimentais que demonstrem o desvio angular da polarização devido à descorrelação entre canais, através da análise da evolução da polarização do sinal óptico em função da PMD, do comprimento de onda e do espaçamento espectral; foram analisadas duas propostas para se utilizar no controle de polarização; estatísticas referentes à atenuação dos canais utilizados foram realizadas e também o cálculo da correlação com intuito de analisar como esses canais se relacionam. / [en] This work presents the study and conducting experiments to investigate the PMD (Polarization Mode Dispersion) effects in polarization control implemented in a single-mode fiber optic link. This study will allow the optimization of polarization controllers in transmission systems that will use polarization multiplexing (PolMux) combined with techniques like UDWDM (Ultra Dense Wavelength Division Multiplexing), and thereby to increase the transmission rate in a channel. Therefore, we performed experimental measurements showing the angular displacement of the polarization due to decorrelation between channels by analyzing the evolution of the polarization of the optical signal as a function of PMD, wavelength and the spectral spacing, analyzed using two proposals for the control of polarization, statistics of the fading channels used and also performed the calculate the correlation with the aim to analyze how these channels are related.

This doctoral thesis deals with present trend to turn up the bit rate of the optical fibres making use of wavelenght multiplex systems. There are new theoretical and practical problems caused by the new technologies. Except the known modal dispersion there exist problems caused by chromatical and polarization mode dispersion. In the opening of the thesis the known effects, which influence the payload signal, are introduced. The polarization mode dispersion has the main attention. Within the scope of this thesis there has been programmed the statistical calculator which can analyses the measured values of differential group delay by Monte Carlo calculation. Next meaningful output is the designating application of the optical routes. It is possible to mathematicaly unambiguously define the polarization mode dispersion by Jones, Stokes and Poynting vectors. This complicated calculations are mechanized and in the simulation application make possible to simulate the signification of the PMD influence at different input parameters. The thesis includes the study of the PMD modulation format impact with the results of simulations and confrontation with other scientists results. The significant output are the final practical results examinations, which can be implemented thanks to the possibility of using the FTB-5500B measuring device.

[pt] Neste trabalho é desenvolvido um modelamento matemático para os elementos que compõem um sistema de compensação de PMD de primeira ordem, visando obter alternativas de solução para a metodologia de controle do sistema de compensação. Um algoritmo de controle utilizando uma lógica simplificada, diferente das encontradas em outros sistemas de compensação, é desenvolvido. Os resultados das simulações matemáticas, das diferentes partes do sistema de compensação e do algoritmo de controle desenvolvido, são comparados com resultados experimentais, obtendo-se uma excelente concordância. Um protótipo de um compensador de PMD de primeira ordem, utilizando diferentes topologias de compensação, é implementado e os resultados experimentais apresentados. Os resultados experimentais obtidos demonstram que a performance do protótipo desenvolvido é melhor que à obtida com outros sistemas de compensação desenvolvidos por outros grupos de pesquisa [22, 60]. / [en] In this work a mathematical model for the elements of the first order compensation system is developed to obtain alternative solutions of control methodology of the compensator. A control algorithm, using a simplified logic, different from the ones found in other compensation systems, is developed. The mathematical simulations results of the implemented model for different parts of the compensation system and of the control algorithm are compared to the experimental results showing good agreement. A first order PMD compensation prototype is implemented, using different compensation topologies. The experimental results are presented, proving a better performance when compared to the experimental results obtained by other research groups [22, 60].