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Dispersion measurements of optical transmissions.
Motúz, Rastislav ; Urban, František (referee) ; Filka, Miloslav (advisor)
This thesis firstly theoretically describes phenomena which appear in optical fiber transmission. The theoretical part of the thesis deals with linear and non-linear phenomena, and later on proceeds to dispersions with a more significant effect on the optical transmission quality. It puts polarization to the centre of the phenomenon called Polarization mode dispersion (PMD), which is the main object of our interest. It leads to a deep PMD description from the point of view of polarization states, limit values, compensation methods, and methods of measurement. The practical part of this thesis deals with a draft of PMD measurement via Fixed Analyzer method. For the purposes of this measurement, we used the optical spectral analyzer MS9740A. In order to compare measured values, the proposed idea then proceeds to the reference measurement by using a modular platform EXFO FTB--200 in combination with CD/PMD module EXFO FTB-5700. Results of measurements have been evaluated for the limit values defined by the standard. In the last chapter of this thesis, the reference measurements are compared to the Fixed Analyzer method. All the advantages and disadvantages of individual measurement methods are identified at the end of this chapter too.
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Standards for application of polymer optical fibres
Stiburek, Martin ; Tejkal, Vladimír (referee) ; Šporik, Jan (advisor)
The aim of thesis is description of polymer optical fiber (POF). In particular, focusing on their application and its associated standardization. After explaining the principle of signal transmission by polymer fibers, glass fibers are compared with the polymer fibers. The attention is then paid to the types of POF and their connectors. Another part is engaged in standards of polymer fibers, according to their area of application. Following chapter describes the application of polymer fibers in practice, especially in the automotive industry and sensor technology. Standalone chapter is dedicated to deploying POF fibers in LANs. It mentions comparasion with copper and wireless networks, summarizes the advantages and disadvantages. Chapter also provides an overview of the components used in POF - optical converter, switch with optical interfaces, optical network card, etc. In the practical part is created the design of home network for two-storey family house. The proposal was implemented by CableProject CAD software, first using copper cabling (UTP category 5e) and then using polymer fibers. Finally, both proposals are compared with each other. It has been made detailed financial analysis, compared performance of instalation and methods of cable instalallation. The practical part is also dedicated to measuring the parameters of POF networks, the impact of the attenuation loss, explores methods of joining glass and polymer fibers and is engaged in IPTV transmission simulation in real conditions.
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Methodology for the measurement of optical arterial network
Chleboun, Jan ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
There are methods to extend the transmission channel of optical transmission medium thanks to the development of telecommunications and informatics. Multiplex is a grouping of signals into a single transmission path and wave-division multiplexing is the best reason of use of the maximum fiber optic transmission capacity. The subject of this work is to determine whether a particular transmission path is suitable for such an extension of their capacity and how much. The answer is obtained by measuring the attenuation, the chromatic dispersion and the polarization mode dispersion, whose values are strictly limited and which determine next steps in the expansion of the transmission path, which is comprised by optical medium. Measurement methods determine the nature of the measured route and its current transmission capacities. Draft of the measurement methodology, which ensures the correct procedures during a possible transition to higher speeds is the output of this work. Thanks to the acquired characteristics of the BAPS (the Brno Academic Computer Network), the bit rate 40 Gb/s can be provided on this part of the network under the conditions of the introduction of certain countermeasures, particularly the exchange of a connectors on the measured optical lines. As for the back reflection lines in excess of the standard recommendation and pre-emptively on the lines with values with still agree with the return loss. Countermeasure for limiting of the chromatic and the polarization mode dispersion are do not need to stand in the way of a planned transition to a higher rate of the BAPS.
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Design of Graphic Interface for Calculation of Differential Group Delay
Vohralík, Jan ; Křivánek, Vítězslav (referee) ; Kyselák, Martin (advisor)
The Bachelor's thesis is aimed to the problems regarding Polarization mode dispersion in optical fibre. Polarization mode disperzion limits the bandwidth of high speed comunication system. It cases a differential group delay between different polarizatins. If the delay is too high than the bits overlap and a bit error rate is increased. The work include description of polarization in Jones space and Stokem space. For description of Polarization mode disperzion is used PMD vector. I demonstrate influence of differential group delay in optical fibre at special grafic program develop in C# language.
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Design of Multiplex Optical Fibre Link
Krejča, Libor ; Křivánek, Vítězslav (referee) ; Kyselák, Martin (advisor)
In this thesis I consider problems of optical multiplexers, optical amplifiers and designing optical networks with this components. CWDM and DWDM are the most common used multiplexers today. I describe principles of realization multiplexers from basic level to realization in WDM networks. EDFA is also common used amplifier today and I describe his internal structure and how it works. Today, we can observe many realization of optical netwoks with Raman amplifiers, especially in long haul networks. Raman amplifier is characterized in brief. In next chapter I describe the design of optical communication systems and the main designing equations are explained. Then I used the equations for example of designing optical communication system with multiplexers, EDFAs and other components, which are needed for function of the system. In last chapter I explain mathematical model of signal propagation in optical fiber called nonlinear Schrodinger equation, which includes main optical effects in fiber like chromatic dispersion or Kerr effect. The simulation model and his numeric solution was designed including PMD effect, the simulation model is programmed in MATLAB.
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The Optical Link Error-Rate Determination
Joch, Antonín ; Kapoun, Vladimír (referee) ; Kyselák, Martin (advisor)
The master thesis discusses physical causes of light polarization and problems brought by nascence of Polarization Mode Dispersion (PMD). These problems occur especially by high speed systems on optical cable traces. The thesis deals with actuation of transmitted signal by influence of Inter Symbol Interference and it also deals with methods for its measuring and compensation. As a results of measurements are in text presented data provided by EXFO Electro-Optical Engineering Inc. Company. Significant part of the thesis focuses on optical link Bit Error Rate (BER) which is connected with Signal to Noise Ratio (SNR) and signal quality (Q-factor). Further on it is possible to find in text about so called eye diagram which is display mode that shows influence of communication channel on shape of the transmitted signal. To this diagram is related another one called constellation diagram which describes modulation mode and makes it possible to map dispersion of signal points around their nominal values. In connection with so called trajectory it makes vector diagram. Practical part includes depiction of these diagrams in MATLAB development environment.
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The impact of polarization mode dispersion on error-rate of optical fibre link
Dorociak, Petr ; Křivánek, Vítězslav (referee) ; Kyselák, Martin (advisor)
Master’s thesis engages in the impact of polarization mode dispersion on optical communication system. Polarization mode dispersion is mathematically described by Stoke’s and Jone’s space and ensure the theoretic causes of the rise of polarization mode dispersion that are divided on the external and internal effects. On the basis of these effects grow up a differential group delay (DGD) which makes causes that individual polarization modes have between them a time delay and limitation of maximum bit rate. Then master´s thesis analyses the influence of the polarization mode dispersion on the pulse enlargement and on the modulation signal. In this work, there are described the most applicated optical modulation formats. Polarization mode dispersion has also influence on the bit error rate of optical fibre link and closing of eye diagram too. Eye diagram is used to view the transmission characteristics and diagnoses the channel errors. Eye diagram is connected with the definitions as a bit error rate (BER) and signal-to-noise ratio (SNR) that are explained in this work too. Following the gained experiences it was designed an useful graphic interface to display the effect of the polarization mode dispersion on the transmitted signal. Realization of the graphic interface is created in the program MATLAB. In Matlab-Simulink are created six models according to the kind of modulations with characteristic AWGN (Additive White Gaussian Noise) channel. Program was tested for a typical values. In all calculations it is counted only with the losses that are caused by the polarization mode dispersion. It is not calculated with the losses that are caused by a chromatic dispersion and attenuation. At the end of this work are evaluated all types of modulation formats depending on the polarization mode dispersion, optical fibre length, price and complexity of the realization. Atteined results of my master’s thesis are compared with two foreign articles.
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Carbon Fibre Composite Materials
Mikula, Martin ; Molliková, Eva (referee) ; Němec, Karel (advisor)
In the first part of a Bachelor's work there is a general introduction with composite materials. These materials are seperated on the basis of matrix kind. The production of composite materials is described as well. The second part is focused on the carbon fibre materials in more detail. The application of composite materials in aviation industry is in the third part of the Bachelor's work.
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Server monitoring component
Boček, Jaromír ; Heriban, Pavel (referee) ; Roupec, Jan (advisor)
This Bachelor thesis deals with the development of a universal server monitoring component for collecting data from various servers. This component meets the requirements for easy installation, setup and activation of the specified server. The monitored unit releases information that the monitored server is active and completely functioning, in particular, information on CPU utilization, state of disk utilization, and state of all logged users. The presented multiplatform concept puts emphasis on the most common platforms, such as Linux and Windows. In addition, transfer of acquired data through the Internet obstacles in the form of firewall configurations and other security technologies has been solved within this work.
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Development of Multithreaded Applications on the Java 8 platform
Souček, Dan ; Pecinovský, Rudolf (advisor) ; Pavlíčková, Jarmila (referee)
This master thesis is a programmer's guide book of a concurrent programming on the Java 8 platform. Concurrency brings additional issues that cannot occur in single-threaded ap-plications. One of the thesis' objectives is to analyze these issues and introduce several principles that, in case they are properly followed, help to create flawless and well-behaving concurrent applications. Another goal of this thesis is to describe the Java con-currency programming from the theoretical point of view. Firstly, the thesis is focused on basic thread development and synchronization issues. Later, it introduces the features and instruments that are provided by Java 5 and higher versions. The theoretical passages are enriched by practical examples that perform discussed features and help to clarify some specific issues. The thesis is written in Czech language and covers large set of concurrency topics from the very basics through the utility libraries to modern instruments present in Java 8.
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