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The influence of air ionization on the laser beam propagation
Fučík, Milan ; Kubásek, Radek (referee) ; Drexler, Petr (advisor)
The semester project deals with the mechanisms of propagation of electromagnetic wave in ionized environment. The focus is placed on the propagation of light in ionized air. The air ionization influences its properties in the view of its material parameter – permittivity. The change of air permittivity results in the light speed reduction. The theoretical analysis of light propagation is carried out in the work in the view of impact on the light speed. The light speed reduction in ionized air is experimentally verified. The conclusions on the practical utilization of this ionization measurement method are given.
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Automated Procedures for Coherence Controlled Holographic Microscope
Dostál, Zbyněk ; Štarha, Pavel (referee) ; Jákl, Petr (referee) ; Chmelík, Radim (advisor)
Coherence-Controlled Holographic Microscope (CCHM) and a Fluorescence Holographic Microscope (FHM) were developed particularly for quantitative phase imaging and measurement of live cell dynamics, which used to be a subject of digital holographic microscopy (DHM). CCHM and FHM in low-coherence mode extend capabilities of DHM in the study of living cells. However, this advantage following from the use of low coherence is accompanied by increased sensitivity of the system to its correct alignment. Therefore, the introduction of an automatic self-correcting system is inevitable. Accordingly, in the thesis, the theory of a suitable control system is derived and the design of an automated alignment system for both microscopes is proposed and experimentally proved. The holographic signal was identified as a significant variable for guiding the alignment procedures. On this basis the original basic realignment algorithms were proposed, which encompasses the processes for initial and advanced alignment as well as for long-term maintenance of the microscope aligned state. Automated procedures were implemented in both microscopes unique set of robotic mechanisms designed and built within the frame of the thesis work. All of the procedures described in the thesis were in real experimentally proved at real microscopes in the experimental biophotonics laboratory. In addition, the control software, which contains the needed automated procedures, was developed for FHM.
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Distributed fiber optic sensors
Holík, Tomáš ; Čučka, Milan (referee) ; Münster, Petr (advisor)
The thesis deals with the possibility of using optical fiber as a sensor. The introduction of the thesis is devoted to the foundations of optics. In addition, the thesis deals with optical interferometry, polarization and dispersion in optical fiber. The main output of the thesis is the comparison of acoustic vibration measurements using interferometric and polarization methods and further measurements on the real route in Brno.
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Optical Distributed Sensor Systems
Dorazin, David ; Münster, Petr (referee) ; Čučka, Milan (advisor)
This bachelors thesis solves possibilities of utilization optical fiber as a sensor. At the beginning the thesis desribes basic principle of ligh transmition in optical fiber, optical fiber and his linear and nonlinear properties. Second part of the thesis deals with sorting of distributed optical fiber sensors and describes each type of the sorted sensor due to principle which they work on. The Michelson interferometer is described and its modification in the form of the Fiber optic Michelson interferometer, which is designed and simulated in the VPIphotonics software. At the end of the thesis is performed measuring of vibrations by the Fiber optic Mach-Zehnder interferometer.
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Workstation for optical interferometry
Blecha, Martin ; Honec, Peter (referee) ; Janáková, Ilona (advisor)
This thesis is specialized on composition of workplace for experiments flowing from optical interferometry. Here are described laboratory exercise servant for demonstration basic principles of interferometry. In more details is described method measurement of height profile objects with method white light interferometry.
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Mechanical design of measurement system for reactive ion etching system
Maňka, Tadeáš ; Antoš, Martin (referee) ; Šerý, Mojmír (advisor)
The aim of this work is to design fully working measuring system for the reactive ion etching system (RIE). The Michelson interfometer, previously developed in Ústav přístrojové techniky, v.v.i., is used in this work. The theoretical part is aimed at description of interferometric methods for precise measuring of length. In next part the etching proces with RIE is described. In practical part the testing system was constructed from the parts of Thorlabs company . The functionality was controlled with this system and the results of measuring were compared with the profilometer. In next step technical drawings were created and the whole system was made.
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Fiber-Optic Sensors
Dejdar, Petr ; Róka,, Rastislav (referee) ; Kyselák, Martin (referee) ; Münster, Petr (advisor)
Optical networks are continuously expanding and this creating space for the use of optical fibers for non-data transmissions. One of them is the use for sensing purposes, where optical fibers can be used to measure temperature, pressure, vibration, etc. In standard conditions or in conditions where the placement of conventional sensors is not suitable (increased humidity, radiation, lack of space, etc.).This paper is devoted to the comparison of technologies comparing sensing systems and describes their principle and their possible applications. Subsequently, the different systems are built and tested. Possible improvements are then proposed based on the measurements, where for the reflectometric system the advantages of using edge detection algorithms are quantified. For the polarization detectors, improvements are made using machine learning classification algorithms with classification success rates above 97 %. Detailed measurements of the sensitivity of optical fibers to acoustic vibrations in three different environments, with different path configurations, cables, vibration-damping materials, etc. are also described. These measurements proved the possibility of intercepting optical fibers using interferometric, reflectometric, and polarization systems, where the polarization system is proven to be the least sensitive and records only lower frequencies. Based on these measurements, a system for securing the physical layer of optical networks is then proposed, which is able to accurately distinguish the quiescent and cable manipulation states from the datasets we created.
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Application of Interferometry in VT UHV SPM
Šulc, Dalibor ; Klapetek, Petr (referee) ; Fejfar, Antonín (referee) ; Spousta, Jiří (advisor)
The thesis is aimed at the development of Scanning Probe Microscopes (SPM). It describes design and development of modular controll electronics to be applied eectively on more microscopes SPM. Control electronics consist of stabilized power source, high–voltage amplier and probe signal amplier. The open–source project GXSM has been introduced. It contains a logic control unit which controls scanning, acquiring data and feedback control. GXSM provides a graphical user interface based on linux operation system. Second part of the thesis is aimed at design and development of interferometric deection sensing system for SPM cantilevers and applications at SPM in general. Designed interferometer has been assembled and tested. It can clearly distinguish a signal of amplitude 2 nm. At the end of the thesis the design of interferometric system implementation is presented.
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Impact of joint implant surface structure on friction behaviour
Kučera, Ondřej ; Nečas, David (referee) ; Ranuša, Matúš (advisor)
In osteoarthritis of small joints, the use of total endoprosthesis is currently being developed to ensure physiological movement, but it provides only a limited-service life. The use of microstructures on the implant surface may improve tribological properties, but this issue is not described enough. Thus, this work addresses the impact of microstructures on friction coefficient, lubricant thickness in the contact area, wear, as well as surface topography and geometry of the structures. Furthermore, the influence of DLyte electrochemical machining on the change of microstructures geometry and tribological properties is investigated. Measurements were performed using a reciprocal tribometer, interferometry and optical profilometry. The textured samples achieved an increase in both friction coefficient and lubricant thickness in the contact area. Furthermore, a correlation between the height of the texture edges and the measured lubricant thickness was demonstrated. DLyte significantly reduces these edges, also reducing wear, however, it degrades the surface of the CoCrMo samples. Implant texturing can lead to reduced wear, prolonged life, and thus improved quality of life for many patients. Texturing of Ti6Al4V alloy in combination with DLyte shows great potential.
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