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Utilization of Nanofibres in the Traditional Ceramics Body
Sedláček, Daniel ; Stančík,, Hynek (referee) ; Sokolář, Radomír (advisor)
This thesis summarizes the current knowledge about ceramic composites with nanofibers. So far, most research focused on the reinforcement of hi-tech ceramics, such as carbides and nitrides, however, this traditional ceramics left behind. Due to the improving the efficiency of production of nanofibers and thus a drop in prices, companies consider their use even in a cheaper ceramic materials. Reinforcement of traditional ceramic shard could theoretically improve many characteristics, but there are absolute minimum of practical researches.
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Optical fibre factors that limit thetransmission capaity of optical lines
Rouča, Tomáš ; Tejkal, Vladimír (referee) ; Reichert, Pavel (advisor)
Bachelor´s thesis more closely specifies effects of attenuation and dispersion of optical fibers in connection with influencing transmitted signal bandwidth and data transfer capacity. It also examines the influences acting on the optical signal passes through an optical fiber and the mechanism that lead to the attenuation or complete suppression of the signal. The first chapter describes in detail the transmission environment in terms of optical fiber attenuation characteristics of the signal loss caused by rough handling of the optical fiber, manufacturing and material specifications, resulting in scattering or absorption of the transmitted signal. Also, whether the description of fiber dispersion, resulting in the shrinking spectrum of transmitted signal and thus the amount of data at a certain point in time transfer to a defined distance. The second chapter analyzes the effects of attenuation and dispersion in fiber optic transmission capacity currently used in presently optic cables, mechanical couplings, connectors and active components. By mentioning a few examples of real transmission lines with regard to the spectral transmission characteristics that these systems require. This study also includes protocols used to transfer information using xWDM systems. The third chapter deals with modern methods to establish a number of optical signals into a single transmission fiber. Particular attention is devoted to describing the principle of association of the channels in the optical frequencies xWDM, since this method does not currently have a standard solution of information transmission optical fiber for its use significantly more bandwidth, longer distances while maintaining vaulted speed transmission and the possibility of flexible extension without laying new cables and reduce the cost of building transmission lines. The last chapter focuses on describing the implementation of a mathematical model to the spectral characteristics of optical fibers.
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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.
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Fiber optical transmission system
Horský, Tomáš ; Münster, Petr (referee) ; Dejdar, Petr (advisor)
Bachelor thesis deals with the program processing for the simulation of dispersion on the optical transmission. Parameters of optical fiber, such as attenuation, diffusion, dispersion, and bandwidth are described in the theoretical part. The main focus is on dispersion while being the key parameter of this work. In the practical part, the measurement characteristics of the eye diagram and its analysis are discussed. Simulator of dispersion can serve both for simulation as well as a measuring device for real transmission routes.
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Design and realisation of a program for measuring equipment EXFO FTB-5700
Stříteský, Radek ; Jurčík, Michal (referee) ; Münster, Petr (advisor)
Main goal of my Bachelor’s thesis is to realize the program for the automatic measurement of optical networks. First part of this project describes the optical fiber, dispersion and types of measurement. There are described chromatic (CD) and polarization mode (PMD) of dispersion. There is described the programming for Windows by using Windows 32 API. Main part are description of creating window of application, work of keyboard and mouse in Windows, sending messages to window procedure and controlling parts in Windows. There is a description of the program and more detailed description of the most important functions in the last part. We can also find here the graphs CD and PMD from the testing automatic measurements.
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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.
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Photonic crystal fibers
Dočkal, Martin ; Tejkal, Vladimír (referee) ; Šporik, Jan (advisor)
This graduation thesis deals with use of unconventional optical fiber with the intention of photonic crystal fiber. There are described types of photonic crystal fiber, their physical, optical and transfer characteristics. There is explained what are the photonic crystals, principle of their function and possible types of crystals. There are also detailed types of photonic fiber commonly used in the optical fiber branch. There is also explained photonic crystal fiber its structure a hierarchy of its types. In this thesis are described and demonstrated different kinds of photonic optical fiber and their use. There is demonstrated principle of one-dimensional periodical structure of Bragg fiber using simulation software. There can be seen graphical comparison of the simulated optical fiber core to commonly obtainable fiber. Outcome of this graduation thesis should be explanation of function of photonic crystal fiber and possibility of finding new type of fiber with optimal dispersion characteristics for use in fiber optics.
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Spectral characteristics in fiber optics
Chleboun, Jiří ; Tejkal, Vladimír (referee) ; Šporik, Jan (advisor)
This bachelor’s thesis is focused on the influence of attenuation and dispersion glass and plastic optical fibers in optical transmission system. Theory of optical transmission is discussed in the theoretical part, it is defined term like spectral attenution characteristic and its division into transmission bands. Sources and detectors are itemized further, which are used for optical transmissions in fiber optics. The thesis describes the most occured effects, which influenced transmission parameters of optical fiber, like optical attenution, dispersion and aspectual polarization dispersion. Theory of plastic optical fibers is processed at the end of theoretical part of thesis. It is also processed advantages, disadvantages and useage of plastic optical fibers and they are consequently compare with glass fibers. Comparison is focused mainly on attenuation, transmission properties and useage on these types of fibers in telecommunication. Representation of spectral attenution characteristics in programme MATLAB is practical output of the bachelor´s thesis. Created programme approximates points which are got from measure optical attenuation by the Lagrange interpolation polynomial.
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Verification of parameters of passive optical components on short wavelengths
Látal, Michal ; Filka, Miloslav (referee) ; Vojtěch, Josef (advisor)
Semestral thesis deals with the basic theoretical knowledge in the field of optics, light propagation and optical fibers. It describes in detail the optical transmission system and its associated issues, such as the attenuation of optical fibers or differently caused dispersion. The main part of this work is a description of each passive optical elements, their production technologies and applications in optical communications. Within the optical connection its radiation sources and detectors of optical radiation are explained. The last practical part is focused on the measurement of insertion loss provided by passive optical components.
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