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Luminescence Diagnostic of Photovoltaic Cells
Stojan, Radek ; Frantík, Ondřej (referee) ; Šály,, Vladimír (referee) ; Vaněk, Jiří (advisor)
Diagnostic of photovoltaic cells defects is one of the key step in production. This dissertation thesis deals about diagnosis of photovoltaic cells by radiative recombination of electron - hole pairs. This radiative recombination is known as luminescence. Diagnostic methods using this local light emission in infrared region have innovative potential. The method of electroluminescence is one of the most widely used luminescence methods whose modifications are applied across the industry, especially in semiconductors. The main area of this thesis research is focused on non-destructive analysis of radiated infrared radiation of monocrystalline and polycrystalline solar cells in various modifications of standard electroluminescence method. In this research there are used two types of CCD cameras are used as luminescent radiation detectors. Method of photon emission microscopy is used for magnification element. Local light emission inspection by microscopy should have benefit to qualitative evaluation of solar cells defects. Radiation emitted by the solar cell has a wave character. This fact brings the potential of using some of the characteristics of the waves. We are talking about the intensity and mainly about new characterization by polarization during the detection of defects in the solar cell surface. Innovation of the measuring workplace of the standard electroluminescence method to use polarization analysis is one of the goals of this dissertation thesis.
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Design of optical fiber temperature sensor for detection of defense perimeter
Zámečník, Ondřej ; Grenar, David (referee) ; Filka, Miloslav (advisor)
This diploma thesis deals with the issue of measuring the ambient temperature using a~single-mode optical fiber used as a temperature sensor. The thesis describes the basic knowledge about polarized light, its propagation in optical fiber and describes special fibers that preserve polarization. It also deals with the representation of polarization states on a Poincaré sphere and the use of Stokes and Jones vectors. In the practical part, several selected methods of optical signal supply to the temperature sensor are measured. Subsequently, the suitability of the given methods is evaluated from the measured results and the courses are compared with the records measured from real routes. This thesis aims to select a suitable connection of a temperature sensor for a long route of optical fiber and verify its functionality.
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Birefringence Influence on Polarization Changes and Frequency on Optical Fiber Sensors
Panascí, Marco ; Grenar, David (referee) ; Filka, Miloslav (advisor)
This bachelor thesis deals with birefringence influence on polarization changes and frequency on optical fiber sensors. The objective of the thesis is to design and implement a set of measurements that analyze these effects. The theoretical part deals with analyzing the polarization-maintaning fiber, the polarization of the light, and the sensory optical fibers, with some research. The practical part deals with design of the workplace, control measurement and sensor response at different temperatures. After the practical part there is a discussion over the measured values. It was found that this sensory optical fiber responds to a change in the ambient temperature of the optical fiber. The main result is that the wavelength varies with temperature.
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Optical Fiber Output Power Temperature Sensor Measuring Optimization
Koláčková, Aneta ; Grenar, David (referee) ; Filka, Miloslav (advisor)
This bachelor thesis deals with the issue of measuring optic power on the output of single mode fiber, used like temperature sensor, using birefringent. Thesis describes the basic knowledge about measuring power, standards and function of optical power meters. It also deals with polarization and representation polarization states using the Poincare sphere. In the practical portion is measured optic power on the output of the temperature sensor with a photodiod and after that is verifed by a polarimeter. The aim of this thesis is miniaturization of ending device for measuring intensity of light, that means replacing expensive and large polarimeter by cheap and small photodiod.
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Polarization properties of laser beam
Březina, Vojtěch ; Hudcová, Lucie (referee) ; Poliak, Juraj (advisor)
Bachelor thesis deals with polarization properties of optical beam and determination her polarization state by Stokes parameters. Further is studied the influence of environment on the polarization of wave. At the beginning of the thesis, fundamental terms which concern wave polarisation including description of polarisation device are defined. In conclusion of the thesis, experimental workplace for polarisation properties measurement using Poincare sphere and Stokes parameters is designed. The object of the experimental part were: measurement of the polarization wave, Mueller matrix measurement, verification function beam splitter and the creation of supportive programs in MATLAB. The results of the experimental findings were determined, allowing to improve measurement.
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Properties of the perspective ferroelectric materials
Krejčí, Josef ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
This thesis studies the properties and the applications of prospective ferroelectric materials which are used in electrical engineering and electronic industry. Further are physically explained and mathematically described the basic principles running in their structure. The practical part is aimed to build a workplace for measuring the components of the complex permittivity in the frequency and temperature area, controlled by the programmed measurement and service application using the Agilent VEE Pro 8.0 and MS Excel. The functionality of the workplace was verified on the selected material samples by measurement and evaluation of selected properties. For this issue was created electronic text, which can be used as a guide for laboratory exercises and it is an integral part of this work.
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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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Polarization in optical fiber
Bilek, Maroš ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
In the theoretical part of the the bachelor's thesis, the first part is devoted to the analysis of the spread of the light beam in the fiber, the parameters of light and various types of fibers. Subsequently, the phenomenon of polarization, its conditions, methods of depiction and writing are described in detail. Furthermore, the issue of polarization mode dispersion (PMD) is explained. Bindings, differential group delay and PMD measurement methods are described. The practical section of the thesis describes the methods and procedures for measuring polarization and polarization mode dispersion. The EXFO FTB-200 measuring platform was used to measure PMD and was equipped with a module for PMD/CD measurement. A polarimeter in combination with a polarization analyzer was used to measure polarization. As part of the long-term measurements, the EXFO FTB-200 measuring instrument was reused in the case of PMD. In the case of polarization measurements, a combination of polarimeter and balance detector was used. Finally, the results of both short- and long-term measurements are displayed. The results of short-term polarization measurements are shown in the form of both, a Poincaré sphere and a polarizing ellipse with a calculated azimuth and ellipticity. Long-term measurements are in the form of graphs that show changes in polarization rotation rate over time. From the displayed results, the dependency of polarization and therefore PMD on the environmental surroundings is concluded.
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