|
|
Measurement of the fiber optical transport links
Ambrož, Jan ; Škorpil, Vladislav (referee) ; Reichert, Pavel (advisor)
This thesis deals with the measurement of optical transport links. In particular, the measurement of attenuation, chromatic and polarization mode dispersion. Specic me- asurement systems using a WDM and passive optical networks. Within each chapter are listed the causes and eects restrictive factors and methods of measurement. In chapter Attenuation measurements are described radiation and material loss as the main causes of depression. Methods whitch are described two lengths, insert loss and reectometri. Chromatic dispersion at dierent speeds of various wavelengths limits systems with high transfer rate. Methods of measuring the phase shift, dierential phase shift, pulse time delay and interference. Polarization mode dispersion is a random phenomenon caused double refraction, must be measured after completion of the route. Scanning wavelen- gth, traditional and general interference, reectometri and the polarimetric are methods of measurement. It described the measurement of WDM systems in three stages of its build. In brief PON networks are presented, with the specicities of the measurement over splitter. Most chapters are supplemented by the results and conclusions of practical measurements. At the end of the work are given by the two standards deal with the measurement of optical transport links.
|
|
|
Assesment of the meaning of Polarization Mode Dispersion
Červenka, Vladimír ; Rampl, Ivan (referee) ; Kyselák, Martin (advisor)
This thesis describes the most important types of distortions in fibre optics during transmission. They are divided into two main groups, linear and nonlinear. The linear phenomena consist of internal and external attenuation, different kinds of dispersions and negative effect of signal noise. The special attention is focused on polarization mode dispersion. The impact of the nonlinear phenomena on fibre optics in high date rate is discussed as well. Furthermore, the negative effects in fibre optics and their causes are deeply analyzed on results gathered from simulation of some transmission lines. There are presented many methods for counting the meaning of polarization mode dispersion, for example the theoretical model including implementation on physical layer and reducing power looses. Some examples of designing fibre optic lines are introduced along with calculation for them.
|
|
|
PMD - polarization mode dispersion and its effects on data transport
Trávníček, Pavel ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
My graduation thesis is concerned with the effect of polarization mode dispersion on transmitted signal by optical line. It describes external and internal causes of origination of polarization mode dispersion. On the basis of these effects there is a differential group delay (DGD). It is the time delay in meantime within individual modes. DGD results in a time extension of impulsion and limitation of maximum bit rate. This thesis contains localization methods of part of gossamer filament with increased value of PMD by POTDR method. This method is based on the principium of back dispersion and its modifications SOP a DOP. Very important chapter of this thesis is the measurement of the polarization mode dispersion. There are described methods of PMD measurement. It is the interferometric and polarimetric method and the method of state of polarization. The major part of this thesis is about the reduction of polarization mode dispersion effect. This part is divided into two parts. First part is about the methods of PMD effect reduction and the second one is about the PMD compensation. The discrepancy between these two parts is the reduction way of PMD effect on transmitted channel. The compensation use the compensation components inserted into the transmission path. By PMD reduction methods we can solve the problems from the view of changing of fibre or all cable. For better understanding of polarization mode dispersion effect there are simulated 4 optical lanes of various parameters. The simulation output is the eye diagram which provides the view at results of transmission lane. In the final part there is the evaluation of measured parameters of optical lanes simulated in a laboratory.
|
|
|
Use of optical fiber as a temperature sensor
Procházka, Jakub ; Škorpil, Vladislav (referee) ; Filka, Miloslav (advisor)
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.
|
|
|
The Optical Fibre Dispersion Effects on Multiplex Transmission Systems
Kyselák, Martin ; Filka, Miloslav (advisor)
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.
|
|
|
Polarization mode dispersion
Turský, Aleš ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
The work deals with dispersive effects of single mode fibers. We learn about the chromatic dispersion, the main attention is paid to the Polarization Mode Dispersion. We clarify the root cause origin of the Polarization Mode Dispersion describing parameters and its effect on transmitted data. Further on, the works dedicates to measure methods of the Polarization Mode Dispersion which is the interferometric method or the POTDR method. We explain the ways of the PMD removal at contemporary optic routes and options of PMD compensation by using compensators of various types. There is also mentioned the possibility of profiting from the soliton transmission. The last chapter deals with measuring of a real optic route. It includes measured data and its evaluation due to the ITU-T demands.
|
|
|
Polarization in optical fiber
Bilek, Maroš ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
In the theoretical part of the the bachelor's thesis, the first part is devoted to the analysis of the spread of the light beam in the fiber, the parameters of light and various types of fibers. Subsequently, the phenomenon of polarization, its conditions, methods of depiction and writing are described in detail. Furthermore, the issue of polarization mode dispersion (PMD) is explained. Bindings, differential group delay and PMD measurement methods are described. The practical section of the thesis describes the methods and procedures for measuring polarization and polarization mode dispersion. The EXFO FTB-200 measuring platform was used to measure PMD and was equipped with a module for PMD/CD measurement. A polarimeter in combination with a polarization analyzer was used to measure polarization. As part of the long-term measurements, the EXFO FTB-200 measuring instrument was reused in the case of PMD. In the case of polarization measurements, a combination of polarimeter and balance detector was used. Finally, the results of both short- and long-term measurements are displayed. The results of short-term polarization measurements are shown in the form of both, a Poincaré sphere and a polarizing ellipse with a calculated azimuth and ellipticity. Long-term measurements are in the form of graphs that show changes in polarization rotation rate over time. From the displayed results, the dependency of polarization and therefore PMD on the environmental surroundings is concluded.
|
|
|
Dispersion effects in high-speed optical networks
Filip, Tomáš ; Šporik, Jan (referee) ; Tejkal, Vladimír (advisor)
This bachelor’s thesis is focusing on optical transmission principal, its transfer mediums and furthermore also with focusing on its advantages and disadvantages. First half of this thesis focuses on adverse influences, which affect signal transmission in optical networks, on dispersion influences, especially on Polarization Mode Dispersion (PMD). Second half of this thesis deals with measuring of properties of optical fibers, largely chromatic and polarization mode dispersion, used methods and its principals. Furthermore, there are mentioned current compensation possibilities. The seventh chapter deals with optical route simulation in OptiSystem and testing chosen compensation methods for bit rate 40Gb/s. In the last chapter there are elaborated results of real optical route measurements for Masaryk University.
|
|
|
Temperature Dependence of PMD
Drábek, Jakub ; Hanák, Pavel (referee) ; Münster, Petr (advisor)
Bacherol thesis describes the problems of polarization mode dispersion-PMD. Size of the delay PMD is a random variable that varies in time. When operating at high data rate communication links is one of the major problem of the optical fiber. PMD value affects many different environmental influences as temperature, and therefore the measurement of PMD become standard in deploying high-speed optical networks.
|
|
|
Polarization mode dispersion - PMD
Ťupa, Martin ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
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.
|
guest ::
