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Interferometric Measurement Of Optical Signal In Turbulence
Kovaľová, Soňa
This project deals with the measuring of the impact of atmospheric turbulence on laser beam used in wireless optical communication. The method is based on interferometry with using of Michelson interferometer. Mathematical apparatus comes from Kolmogorov’s cascade theory and statistical analysis.
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Coupling Of Laser Beam Into Optical Fibers
Růžičková, Barbora
Our project deals with examination of coupling of laser beam into optical fibers. In the first part of our project theoretical knowledge essential to the practical part was gathered. Subsequently the effectiveness of 4 different manual coupling methods was measured. In addition, measurements to the numerical aperture in both single- and multi-mode fibers were completed. Finally, the obtained data were made into comparison of the efficiency and suitability of individual fibers and methods for manual coupling.
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Position sensing detector
Ha, Tuan ; Wilfert, Otakar (referee) ; Barcík, Peter (advisor)
This thesis deals with design of a laser position detector. Different types of sensor are mentioned and compared at the beginning. Special attention is paid to quadrant sensor. Its pros and cons are discussed with designing methods. The sensor is simulated in Matlab to test its output response. Then the laboratory tests follow to meassure real response of the chip. Then follows the design of the detector based on measured and simulated data. In the conclusion of this thesis parameters of created device are evaluated.
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Interferometric measurement of optical signal in turbulence
Kovaľová, Soňa ; Křivák,, Petr (referee) ; Hudcová, Lucie (advisor)
The aim of this thesis is to quantify the impact of atmospheric turbulence on optical signal used in free space optic communication systems. The first part is associated with atmosphere as transmission medium. Following part deals with interferometry and components of interferometers. Various methods of analysis of trasmission environment for optical beam are introduced theoretically and experimentally. Mathematical apparatus based on Kolmogorov’s cascade theory, Rytov’s variance was used to find value of structural parameter of refraction as a main measure of turbulence intensity. Experimentally obtained data were subjected to statistical analysis. The visualization of interference pattern fluctuations under turbulent conditions is shown in the last section. Interferometric method was realized with Michelson interferometer.
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Design of motorized optical system used for focusing of a laser beam
Zobač, Evžen ; Novotný, Karel (referee) ; Novotný, Jan (advisor)
This diploma thesis deals with the structural and optomechanical design of automatization of focusing laser beam for a remote laser spectroscopy device. The chosen solution uses an active rangefinder and a rotary unit to control the change of the focus plane of the device's optic system. The dependence of the focus plane’s change on the shift of lens in the focus plane was practically measured. For proper control of the rotary unit, this dependency is needed. Structural parts were made based on the created drawing documentation. The structural parts were mounted in the existing assembly of the device together with the purchased components. The proposed solution enables a change of the optical system, for example, in order to obtain a more appropriate range of focal planes.
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Rotary flash hardening with help of electron beam and laser radiation
Klusáček, Martin ; Jan, Vít (referee) ; Kouřil, Miloslav (advisor)
This master thesis deals with surface hardening of steels, especially with rotary flash hardening of 42CrMo4 steel (WNr 1.3563, ČSN 15142). In this method homogenous heating of whole surface occurs during a very fast rotation of the component. In the theoretical part of this thesis the most common methods of surface hardening are described, with focus on laser and electron beam technologies. In the experimental part special device for this application was constructed. Rotary flash hardening was done using different radiation source and experimantal device parameters. The hardened surface layer of maximal thickness of 0,7 mm and width of 5,6 mm was achieved using laser beam. Results with electron beam were way better, because this technology allows to control the distribution of power along the beam width in order to improve the width/thickness ratio of hardened layer. Using this method maximal layer thickness of 1,4 mm and width of 13,4 mm was achieved.
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Comparison of laser welding and electron beam welding technology
Trost, Daniel ; Búda, Jaroslav (referee) ; Mrňa, Libor (advisor)
Thesis presents a comparison of technical evaluation of two welding technologies – dismountable connection of two materials, in this case superalloy Inconel 718. On the basis of the technological park of Honeywell Aerospace Olomouc s.r.o. coming into consideration still used the electron beam welding method which is compared in this work with the laser welding due to speed up the welding and a little heat input during the process of the welding.
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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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Evaluation of Surface Quality When Using AWJ And WJM Cutting Methods
Pecháček, Martin ; Dvořák, Jaromír (referee) ; Slaný, Martin (advisor)
This study deals with technology of abrasive water jet material cutting and influence of cutting head feed rate on surface topography of cut walls with regards to roughness. Eight parameters were chosen based on the CSN EN ISO 4288 standard representing quality of surface after AWJ cutting. When AWJ cutting the chosen material – commercially pure ASTM B265 grade 2 titanium – feed rate was being changed and in order to obtain information about each parameter´s distribution in various depths of the cut, surface composition was evaluated. It was found out that feed rate has significant influence on surface and that the profile elements´ width grows when increasing the feed rate and cut depth. Furthermore, two selected feed rate results were compared to laser beam technology and conclusion for the selected material was made that AWJ cutting is more preferable due to final roughness and no heat affect on the material.
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Unstability cut of laser beam at dividing limiting gauge thickness
Kadlec, Zdeněk ; Kalivoda, Milan (referee) ; Osička, Karel (advisor)
This thesis deals with the possibilities of cutting strong steel metal sheets by means of laser and problems rising from the incision, their technological investigation. The basic philosophy consists on the research of the interaction between laser bunch and material, depending on the position of focal poin and sequential results in spec. heat. It determines the main parametres of the incision (from the total quantities and matematical description) which have the biggest effect on the occurence of wide cut and perhaps even on the quality of products and consequential optimalization of these quantities.
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