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Measurement of Level by Fiber Optic Sensors
Bednář, Tomáš ; Havránek, Zdeněk (referee) ; Šedivá, Soňa (advisor)
The subject of this master‘s thesis is the issue of design of fiber optic sensor for min/max and continuous measurement of liquid level, which could be used for laboratory measurement of optoelectronics. The thesis is divided into the three parts, the first part deals with methods of retrieval level measurement using fiber optic sensors. The second part is made of plant design of optical fiber sensors, it is shown the implementation of measuring devices for liquid level measurement and measured transfer characteristics of the sensors developed. The last part is proposed for laboratory typing tasks using established preparation for teaching in the subject Optoelectronic sensors.
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Fast simulation of ToF spectrometers
Oral, Martin
A fast simulation method was developed for analysis of time-of-flight spectrometers and it has been successfully used to optimize parameters of a real instrument. In the general case, the function of a time-of-flight spectrometer is best modeled using the Monte Carlo method, That involves calculation of a high number of ion trajectories, which is time consuming. We have found a way to reduce the calculation time greatly by introducing a simplification and using pre-computed data independent on the ion mass and charge. The procedure makes it computationally feasible to run iterative optimizations. By comparing the results with those of a realistic simulation on a selected case, we have verified that there is no noticeable influence on the results.
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Effect of surface of semiconductor nanocrystals on their properties: investigation by laser spectroscopy
Preclíková, Jana ; Malý, Petr (advisor) ; Franc, Jan (referee)
The topic of the diploma thesis is chemical treatment of the surfaces of semiconductor nanocrystals CdS and CdSe in the form of thin nanocrystalline films prepared by chemical bath deposition. The evolution of photoluminescence and absorption spectra was investigated under treatment by water, toluene, butylamine, pyridine and hydrogen peroxide. The strongest changes were observed by samples soaked in water, pyridine and aqueous solution of pyridine. The observed effects were explained by partly dissolving of nanocrystals by water and affecting behaviour of photoexcited holes in the presence of the strong hole acceptor pyridine. The second part of this diploma thesis deals with photochromic properties of silver nanoparticles in a titanium oxide matrix. The photochromic behaviour of the samples was examined in detail. A phenomenological model of photochromic changes was suggested in analogy with the hole burning spectroscopy. In order to better understand the microscopic processes in this composite material other experiments were realized - e.g. samples were UV irradiated, or laser illuminated under lowered air pressure, pump & probe experiment. Under laser irradiation optical extinction of some nanoparticles was decreased. Simultaneously, changes of plasmon resonances of the rest of nanoparticels were...
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Development of solar diffuser.
Pintr, Pavel
Theoretically attainable productions of photovoltaic plants depend on the quality of solar sensors. We can determine an effeciency and reliability of photovoltaic plants with them. We introduce optical simulation of the original solution of solar sensor in software Optic Studio 15.5 Zemax. We propose new diffuser shape of solar sensor according to our analyse. We\ndescribe a development of first prototypes and their testing in the real conditions.
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Proceedings of multidisciplinary conference LASER56
Růžička, Bohdan
Conference LASER56 is a multidisciplinary and intersectoral event where different kind of specialist can meet each other. They come from various environments (private company, university, public research organization etc.). Their common denominators are laser, optics and its applications.\n\n
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Optical fibres and their polarization effect
Klesnil, Ondřej ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This project describes the fundamental concepts and basic theory of polarization mode dispersion (PMD) in optical fibers. There are described basic the relation between Jones vectors and Stokes vectors, rotation matrices, the definition and representation of PMD vectors, the laws of infinitesimal rotation. After the introduction the first conception with bases of polarization mode dispersion (PMD) in optical fibers, they have become an important body of knowledge basic for the design of high-capacity optical communication systems. PMD effects are linear electromagnetic propagation phenomena occurring in so-called “single-mode“fibers. Despite their name, these fibers support two modes of propagation distinguished by their polarization. Because of optical birefringence in the fiber, the two modes travel with different group velocities, and the random change of this birefringence along the fiber length results in random coupling between the modes. With current practical transmission technology the resulting PMD phenomena lead to pulse distortion and system impairments that limit the transmission capacity of the fiber. I describe different ways of measuring PMD in optical fibre, PMD compensation techniques and analyse PMD results in optical fibres.
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