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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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Optoelectronic sensor of polarization state of transmitted light
Bajgar, Aleš ; Rampl, Ivan (referee) ; Tománek, Pavel (advisor)
The living body tissues consist of cells which dimensions are bigger than a wavelength of visible light. Therefore a Mie scattering of transmitted light occurs and different polarization states arise. The changes of polarization state due to the multiple scattering of light in the biological cellular tissues allow measure the aging of biological tissue. The transmitted polarized laser light exhibits multiple scattering on the thin slice of sample.
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Measurement of the piezoelectric charge coefficient
Stehno, David ; Uher, Miroslav (referee) ; Fialka, Jiří (advisor)
The thesis aim was to study in theory the determination of piezoelectric coefficients, in particular piezoelectric coefficient of charge and to use different measurement methods to determine this factor. Also to further study the issue of determining the uncertainties and determine the measurement uncertainty. Measurements were conducted on cylinder-shaped samples, with different dimensions of individual samples. With type material PCM51 and PCM41. Piezoelectric coefficient measurements of charge was carried out using three methods: frequency, direct and quasi-static. The results achieved by all methods are compared at the end of this study and the measurements uncertainty are calculated and discussed for each method.
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Electrical characterization of flexible nanofiber piezoelectric materials
Pokorná, Romana ; Holcman, Vladimír (referee) ; Tofel, Pavel (advisor)
This bacherol thesis is focused on piezoelectric nanofibrous materials. The first part describes the formation, use and possible aplications of nanofibers. It further analyze the principle of piezoelectric effect. It is a conversion of mechanical energy into electric energy and conversely. The second part is focused on design of experimental workplace for measurement of functional material properties. The last section of the thesis is dedicated to the electrical characterization of PVDF nanofibers and to the measurement of the piezoelectric charge constant.
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Analysis of an Electromagnetic Wave on the Boundary between Electromagnetic Materials
Kadlec, Radim ; Lazar, Josef (referee) ; Macháč, Jan (referee) ; Kroutilová, Eva (advisor)
The proposed dissertation thesis contains an analysis of conditions on the boundary between layers having varied electromagnetic properties. The research is performed using consistent theoretical derivation of analytical formulas, and the underlying problem is considered also in view of multiple boundaries including the effect of the propagation of electromagnetic waves having different instantaneous speed. The author presents a survey and formulation of the basic characteristics of methods used for electromagnetic wave propagation analysis; in this respect, special emphasis is placed on radial models. The processing of the topic involved the designing and verification (using a set of different, layered planar materials) of algorithms to analyze the electromagnetic field components. The algorithm was assembled to enable simple evaluation of all components of the electromagnetic field in relation to the speed of the wave propagation in a heterogeneous environment. The proposed algorithms are compared by means of different numerical methods for the modelling of electromagnetic waves on the boundary between materials; moreover, electromagnetic field components in common points of the model were also subject to comparison. When in conjunction with tools facilitating the analysis of material response to the source of a continuous signal, the algorithms constitute a supplementary instrument for the design of a layered material. Such design enables the realization of, for example, recoilless plane, recoilless transition between different types of environment, and filters for both optical and radio frequencies.
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Properties of liquids based on organic esters
Toulová, Jana ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This master's thesis deals with the electrical insulation fluids used in electronics industry. The analysis of the current state of research and innovations in modern, biodegradable fluids in terms of their use as diagnostics. It is described by the physical nature of polarization and conductivity mechanisms, which are applied in liquids. It was compiled automated workstation for monitoring components of the complex permittivity over a wide temperature range. In the experimental part we analyzed the behavior of liquids selected alternative based on natural esters when exposed to an alternating electric field at various temperatures. Evaluated results are compared with values for conventional mineral oil.
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Optical fiber polarization sensor optimalization for detection of fast and small temperature changes in military objects
Sergeev, Roman ; Grenar, David (referee) ; Filka, Miloslav (advisor)
This bachelor thesis deals with the design of an optical fiber thermal (temperature) sensor suitable for application in a military building. The thermal sensor detects even slight temperature changes based on the change in the polarization state of the light. The thesis describes the basic theory, which serves as a source for understanding the principle of operation of the fiber optic sensor. In the practical part, the basic quantities describing the polarization state of light were measured. The measured values were plotted in graphs to illustrate the dependence. This thesis aims to measure the designed variants of the sensor connection and select the most suitable for temperature measurement.
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Utilization and Suppression of Birefringence Phenomena in Optical Fiber Sensory Applications
Motúz, Rastislav ; Hudcová, Lucie (referee) ; Vlček, Čestmír (referee) ; Drexler, Petr (advisor)
The thesis deals with integral and distributed optical fiber sensors of electric current. In the area of integral sensors the analysis is performed by Jones matrix calculus and the simultaneous influence of induced circular and undesired linear birefringence using an ortho-conjugation retroreflector. Furthermore, the proposed conjugation loop variant using half-wave phase retarders is analyzed. The theoretical conclusions are confirmed by simulation and experimental measurement. In the field of distributed fiber optic sensors, analysis and simulation for the detection of plasma currents in thermonuclear fusion reactors, based on the POTDR technique, is performed. An improvement procedure is proposed for circular-shaped vacuum vessel reactors. Plasma current detection procedure in divertor-type reactors have been newly designed and simulated to investigate the effect of the OTDR detector noise on plasma current detection accuracy.
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Application of nanofiller in electroinsulating materials
Mohyla, Petr ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This project deals with calculation parts of complex permittivity varnish samples which is filled by nanoparticles of metal oxides. Opening of this project deals with theory of dielectric and effects in dielectric, theory of compounds and expressions in composite systems. Following topic is theory of nanoparticles and nanotechnologies and summarize adjusted results about this branch of knowledge. In practical part of work is include method which was use to make varnish samples filled by nanoparticles, prepare to measurement methods and whole results of measurement. In the end of work is analysis influence of filler particles each filler types to dielectric material and results verified mixture mathematical expressions.
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