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Fiber-optic sensor based on multi-mode interference
Hedl, Michal ; Havránek, Zdeněk (referee) ; Šedivá, Soňa (advisor)
This diploma thesis is focused on measurement of the physical quantities by fiber optic sensors based on multimode interference. The objective is to evaluate the appropriate method of signal provided by the spectrum analyzer. Firstly, a review of optics, optical phenomena and fibers is performed. The basic theory necessary for the realization of measurements and the principal of fiber optic sensors and SMS (singlemode–multimode–singlemode) structures are discussed. Finally, the automated measuring workplace for absorption spectrum measurement is created and described. Given data are finally evaluated by an artificial neural network and a sensor concept for practical utilization is designed.
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Optical fiber sensor based on Michelson interferometer
Kopáč, Ondřej ; Grenar, David (referee) ; Čučka, Milan (advisor)
This bachelor thesis deals with description and simulation of Michelson unbalance interferometer and description of fiber optic sensors. The simulation is realized by MatLab. The thesis also described basic optical phenomena, types of optical fibers and two types of interferometric detection. The thesis also deals with description of measurements and their results.
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Longitudinal index structures in optical fibers
Polreich, Štěpán ; Čučka, Milan (referee) ; Urban, František (advisor)
This thesis describes basic concepts, principles and properties of optical fibers. Considerable part is devoted to fiber gratings that are created by a change in the refractive index in the optical fiber core. In this work is described description, principle, method od production and distribution of gratings on Bragg gratings, gratings with long period and chirped gratings. In this thesis are also presented different types of lasers and their advantages over other lasers. A large part deals with the description of the femtosecond laser, with which the structures will be later made into the material. In addition, the laser modes are differentiated, this is a mode of micro-machining and modification or a change in refractive index of the material. The last part deals with change the refractive index in planar technology, the creation of a groove for fastening the fiber and attempts to write the gratings into the optical fiber. Created fiber sensor are tested for temperature and tensile changes. Finally, the practical use of sensors made by femtosecond laser and the advantages over UV laser and phase mask techniques are presented.
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Simulation of Mach Zehnder interferometer
Rozsypal, Filip ; Münster, Petr (referee) ; Čučka, Milan (advisor)
This bachelor thesis deals with the simulations of Mach-Zehnder and Michelson interferometer. These simulations are realized by VPIphotoncs and MatLab. The thesis also describes the optical and physical phenomena, the usage and the principle of operation of interferometers and results of measurements with validation of the basic work of both interferometers.
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Sol-gel synthesis of ternary ZnxTiyOz nanostructures for applications in solar cell technologies and photonics
Mrázek, Jan ; Nižňanský, Daniel (advisor) ; Pinkas, Jiří (referee) ; Pollert, Emil (referee)
The presented study deals with the sol-gel synthesis of nanocrystalline ternary phases of the general formula ZnxTiyOz, their characterization and potential application in photonics. Achieved results brings new fundamental knowledge about the processes leading to the formation of ZnxTiyOz nanocrystals from amorphous xerogels and gives novel information about structural and opto-electrical properties of prepared materials. Based on the presented results, most of all up-to-date reported ZnxTiyOz compounds with tailored nanocrystalline size and structure can be prepared as powders or thin films. Two sol-gel approaches based on the cluster process and direct heteronucleation were employed to prepare initial sol. Sols were optionally doped by Eu3+ ions to evaluate the effects of rare earth element to crystallization properties of formed compounds. In the first part of our study crystallization properties and structural evolution of thermally treated xerogels were analyzed. As a result a versatile method allowing the preparation of inverse spinel Zn2TiO4, cubic defect spinel ZnTiO3 and rhombohedral ZnTiO3 with tailored nanocrystal sizes was established. Initial composition and thermal annealing allow us to prepare selected ternary phase with tailored nanocrystal size ranging from tens of nanometers up to...
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Testing of optical networks
Šimoník, Jan ; Horváth, Tomáš (referee) ; Filka, Miloslav (advisor)
The aim of this bachelor thesis is to describe testing of optical networks physical layer by norms and recommendations (CSN, ITU and RFC). The first chapter provides a description of the individual optical fibers, their division and a brief description of each type. In the next part of this thesis, the methods and procedures for testing the various parameters of optical networks are described, according to specific standards and recommendations. The issue of testing quality of services is also described, primarily focused on triple play services, which are operated at optical access networks. The following is a description of the issue of access and transport networks, a draft of methodology for testing the physical layer of these networks is given. In conclusion, there is a chapter describing the practical measurements made on a passive optical network. In the annexes of this thesis the limit parameters of optical fibers used for the measurements and draft of the content for measuring protocol are listed.
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Simulation and measurement of dispersions in optical access networks
Kováč, Filip ; Münster, Petr (referee) ; Šifta, Radim (advisor)
Thesis deals with detailed description of the chromatic dispersion–CD and polarization mode dispersion–PMD. In theoretical part is dismantled at the beginning of words and mathematical principles of dispersion, further distribution of dispersion in terms of single-mode and multi-mode optic fibers through compensation, either fibers (chromatic dispersion) or systems (polarization mode dispersion). Theoretical part also consult the standard ITU-T specifically in term of fibers G.652, G.653, G.655, G.656, G.657, are described and compared. The penultimate section deals with major subject and by measuring both of the above dispersions. Finally, the theoretical part is devoted to optical access networks, which describes the optical access network such as its division and at the end describes the different types networks as APON/BPON, GPON, EPON, 10GEPON and XG-PON. The practical part is divided into measurement dispersions (EXFO FTB-5700) and simulation dispersions (OptSim). Both steps use the same type and length of fiber (6 km G.653, 20, 60 km G.652). According before creating the measured and simulation diagrams are obtained fibres parameters, which are finally compared.
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Spectral characteristics measurement of single fibre optical transmission
Balon, Radek ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The main object of the bachelor´s thesis is show familiarize with optical networks and measuring when the fibres are connected to operating network. The whole thesis was separated into several parts. The first part was deals with optic fiber and properties, kinds of optic fibers, methods of propagation light inside fiber and important parameters, which has undesirable effects, such as optic loss and dispesive influences. Next part was concentrated on transfer technologies, which where used for data transmission in operating networks. We talked about differences between technologies and describe the monitoring system, which was used for measuring parameters in operating network. The last part was focused on own measuring. We was measured the parameters in operating network CESNET2 and influence of the signal after connect optic monitoring probe. Measuring was implemented on optical network of Masaryk University in Brno (ÚVT MU).
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Software based optical cable documentation
Martínek, Michal ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The focus of this work is a description of search-optic cables and cables stored in the Earth's surface suitable method and the possibility of registration of the optical paths and components in the ArcGIS geographic information system. The work set out in detail the different types of optical fibers and principles listed in the wiring examples most commonly used cables. There are additional elements used in the construction of optical networks, whether the individual connectors, hubs, etc., as well as protection features most often used for distribution of optical cables. There are also examples given options stowages routes and laying cables, and most currently with the possibility to discover a practical listing and description of these search engines non-metallic elements. The work also focuses on how these elements efficiently record to go to them quickly and easily access and simplify their close location in real space, to ensure unwanted destructive interruption, or any repair, expansion, etc.
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