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Support system for administration and control of FSO transceiver
Janík, Lukáš ; Němeček, Jiří (referee) ; Wilfert, Otakar (advisor)
Tato práce se zabývá problematikou optických bezkabelových spojů (FSO). V úvodní kapitole jsou diskutovány přednosti, základní principy a dílčí komponenty FSO spojů. Druhá kapitola se zabývá atmosférou z pohledu šířícího se optického svazku, jejím složením, základními veličinami a jevy v ní nastávajícími. V následující kapitole je popsáno několik metod ke zmírnění jevů majících negativní vliv na kvalitu spoje. Druhá část práce se zabývá návrhem podpůrného systému pro FSO, založeném na softcore mikroprocesoru MicroBlaze, návrhem jednoduchého síťového přepínače a síťového rozhraní. Závěr práce pojednává o implementaci webového serveru a tvorbě webové prezentace umožňující vzdálenou správu FSO a jeho komponent.
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Optical link intended for indoor network
Hrbáčková, Petra ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
This thesis deals with the structure of the optical wireless link intended for indoor applications. Optical transmitters and optical receivers as the basic elements of optical links and their characteristics and parameters are described. The characteristics of lenses used in the transmitter and receiver are presented. The special chapter is devoted to the directional reflectance properties of surfaces. The last part of the thesis is focused on a specific proposal of the wireless optical links and its power level diagram.
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Utilization of light polarization when filtering the optical signal
Alexa, Jan ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
This master thesis deals with the possibility of separation of useful signal from noise using polarization of laser radiation. This thesis is structured into 5 thematic units. The first unit is focused on laser radiation and its properties. The second part contains a deeper focus on the polarization of radiation, its description and the possibilities of measuring the polarization states. The third part of the thesis is devoted to the design of the measuring chains and identification of used elements. Chapter four contains measurement of status of the polarization and its results. The last chapter analyzes particular measuring chains outputs according to their spectral characteristics.
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Laser transmitter with fiber
Hašek, Jaroslav ; Němeček, Jiří (referee) ; Wilfert, Otakar (advisor)
This master´s thesis deals with communication which is provided by optical devices. Optical wireless links are enforced due to high bit rate, responsibility and noise immunity. Main part of this master´s project is devoted to optical fibre, its characteristic and its usage in laser transmitter.
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Evaluation of KAP-meters in Rtg Devices
Hlavička, Jiří ; Hudcová, Lucie (referee) ; Wilfert, Otakar (advisor)
The main targets of this thesis have been to get familiarized with theoretical and practical aspects of device, used for measurement of the radiation burden of patients in the health service and to verify suitability of them for the assessment of diagnostic referential levels (quantity of the exposure of a patient) within the radiographic examination process as well. For this purpose, several types of x-ray units, equipped with surface kerma indicators, have been used, they are installed at the Trauma Hospital of Brno, at the Faculty Hospital Brno and at the Masaryk Memorial Cancer Institute in Brno.
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Measurement of the optical intensity distribution at the far field
Vitásek, Jan ; Němeček, Jiří (referee) ; Wilfert, Otakar (advisor)
The topic of this master’s thesis is energy measurement of the optical intensity distribu-tion at the far field. Properties of the optical intensity and the optical power are described. In this thesis solution of wave equation is done. The plane wave, spherical wave and Gaussian beam are described. In this thesis, optical trace of laser beam from transmitter laser diode to receiver PIN photodiode is described. One of the solved problems is diffraction on the lens socket. The basic configuration for diffraction investigation on lens socket was created. There were transmitting laser diode, stop with circular apertures and PIN photodiode used in the experiment. In the other part, thesis deals with measuring and detection of the optical beam. Sorts of photodiodes and their characteristics were analysed.
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Model of the Surface Optical Intensity Distribution in the Beam
Wintr, Aleš ; Hudcová, Lucie (referee) ; Wilfert, Otakar (advisor)
The aim of the thesis is first to describe the light beam spreading through free space and its characteristics. The theoretical part of the thesis developed programs that display models of beams. Given the parameters, theses models depict areal dispersion of optical intensity in the cross-section of beams. More specifically, I developed both a 2-dimensional and 3-dimensional model of beam depiction and a 3-dimensional model with variable angle of rotation of the beam trace. For this purpose I used the software Matlab R2007a. In the experimental part of the thesis I assembled a measurement chain and measured optical intensity of selected optical fibre. The measurement chain included laser Promax Prolite 80, optical source LED Promax Prolite 81, optic power meter Exfo 67A, collimator Thorlabs F810FC-1550 and optical fibres with various characteristics. The measured values were used to plot graphs depicting aerial dispersion of optical intensity and these graphs were compared with the theoretical computer model developed in the theoretical part of the thesis.
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FSO transceiver for link quality estimation
Novák, Marek ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
Tato diplomová práce pojednává o zmírnění bitové chybovosti bezkabelového optického spoje s užitím principu reciprocity aplikovaného na komunikační kanál, spolu s možností kódování přenášených dat. V této práci je implementováno LDPC a Reed-Solomonovo kódování pro jejich vyhovující vlastnosti. Zbytková rámcová chybovost je vypočtena a k dispozici jako výstup systému, který je implementovaný v hradlovém poli (FPGA).
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Computer modeling of laser beam
Mittner, Ondřej ; Wilfert, Otakar (referee) ; Raida, Zbyněk (advisor)
This bachelor’s thesis theoretically describes Gaussian beam, its characteristics and its passing through optical elements. The main attention is focused on creating of computer models of Gaussian beam in COMSOL Multiphysics application, detailed description of these models, presentation of achieved results and comparing these results with theoretic presumptions.
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High precision differential thermometer
Sieklik, Ivan ; Wilfert, Otakar (referee) ; Barcík, Peter (advisor)
This work describes the principles of measurements of refractive-index structural parameter. This parameter represent intensity of atmospheric turbulence which is measured by a differential temperature meter. Basic properties of atmospheric transmission environment are specified and their influence on optical wave is stated. Furthermore, this thesis also describes fundamental types of sensors dedicated to temperature measurements. The aim of this work was to create a differential temperature meter which is able to measure the refractive-index structural parameter.
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