|
|
Design of an imaging spectrophotometer for the spectral range 200-700 nm. Verification of the design in a laboratory set-up of the instrument
Doležal, Matěj ; Bouchal, Petr (referee) ; Ohlídal, Miloslav (advisor)
The bachelor thesis is devoted to the design and realization of laboratory setup of an imaging spectrophotometer for the spectral range 200–700 nm. In the introductory part of the thesis, an analysis of physical phenomena and quantities describing them is carried out which are important the given task solution. Research is made for imaging spectrophotometers that were implemented at the Institute of Physical Engineering BUT in the past. Attention was paid to the function and assembly of these devices. A substantial part of the work concerns the design of an imaging spectrophotometer with an angle of incidence of the light beam on the sample close to 90°, which would enable measurement in reflection and transmission mode. An analysis of the phenomena that influence the function of the given spectrophotometer is carried out. Based on this analysis, the design of the test set of the device is carried out. Subsequently, its implementation is described in detail, including the assembly procedure of the given spectrophotometer. Furthermore, the device is adjusted and, simultaneously, possibilities for improving the display quality are formulated. Then a test measurement of the thin layer prepared by plasma jet technology is performed. In the conclusion, the achieved results are summarized and ways to possible improvement of the functional imaging spectrophotometer are indicated.
|
|
|
Use of finite element method for stress evaluation in layers for optical applications
Tesařová, Anežka ; Ohlídal, Miloslav (referee) ; Burša, Jiří (advisor)
This thesis is concerned with the mechanical stress generated in thin layers applied on a substrate. The application takes place at high temperatures and due to different coefficients of thermal expansion of materials, the sample is deformed, and thereby the stress is generated. The first part of the thesis includes the derivation of the Stoney formula for uniaxial and biaxial stress in a layer. Besides, analytical calculations of the normal stress in the layer for the simplified link model, and shear stress on the layer interface were evaluated. The main part of the work consists of solving the problem using FEM modeling. Because the actual temperature behavior during the application was not known, a fictitious temperature load was used as an input. For the samples, the coefficients of thermal expansion of the layer were then searched so that the thermal load resulting deflection corresponds to the experimental data. Three types of models were created, namely the link body model, the axisymmetric model, and the solid model. The axisymmetric model was used for the calculation of samples forming circular isolines during deformation and a volume model for samples forming elliptical isolines. The result of the FEM calculations was the normal stress in the applied layers, for which corresponding relationships were created using regression analysis.
|
|
|
Modification of construction of the device for measuring laser light scattering from rough surfaces
Jaworková, Magdalena ; Klapetek, Petr (referee) ; Ohlídal, Miloslav (advisor)
This diploma thesis deals with a design modification of detection part of the laboratory instrument for measuring the topography of rough surfaces – laser goniometric scatterometer (SM II). Design modification is based on replacement of so far used detector instead for the detector of higher quality with better measurement parameters. The first part of the diploma thesis contains theoretical basics, which are necessary to understand the relationship between scalar diffraction theory and scattering measurements of monochromatic light. The emphasis is on the importance of choosing appropriate detection coordinates, which are affecting the aberrations of detected diffracted light. The practical part is dedicated to improving the sensitivity of the detection part of the scatterometer SM II that is used in The laboratory of coherence optics at IFE FME BUT. This part justifies the choice of the detector which predetermines both the use of optical elements and the overall design of the detection part as the goniometer.
|
|
|
The Official Website of Music Group
Štěpaník, Zdeněk ; Ohlídal, Miloš (referee) ; Jaroš, Jiří (advisor)
This bachelor thesis deals with an implementation of the official website of music group Marshal. The website has been created using programming language PHP and is based on MySQL database. It includes fans registration, photogallery that supports rating and commenting photos, discussions with an option to reply on a particular thread, articles, news, enquiries, etc. The key component for administration is CMS system which was developed to manage contents of the website as a part of this thesis.
|
|
|
Numerical simulation of the laser light scattering from rough surfaces
Šulc, Václav ; Klapetek, Petr (referee) ; Ohlídal, Miloslav (advisor)
A Matlab numerical model for scattering simulation was proposed based on the solution derived from the Beckmann-Kirchhoff scalar theory of scattering of electromagnetic waves from rough surfaces. A series of various synthetic surface samples were obtained using the open source software Gwyddion on which numerical simulations of scattering were carried out. The validity of this numerical model was tested and compared with experimental results.
|
|
|
Design and Realization of the Second Generation Imaging Reflectometer and its Application in Optical Analysis of Thin Films
Vodák, Jiří ; Držík,, Milan (referee) ; Klapetek, Petr (referee) ; Ohlídal, Miloslav (advisor)
The work deals with a technique of imaging spectroscopic reflectometry developed at The Institute of Physical Engineering, Brno University of Technology. The technique is well suited for characterization of samples non–uniform along their surfaces. The technique is primarily used for optical characterization of thin films. First part of the work is focused on basic physical principles of the technique and on ways in which measurement data are obtained. It contains a basic description of evaluating methods and a basic concept of an imaging spectroscopic reflectometer with a description of main parts of such a device. The main part of the work is focused on a description of two devices which were built at The Institute of Physical Engineering together with a description of some of upgrades which were implemented to these devices during their development. A description of measurements done with the two devices is also included. Last part of the work is then focused on further development of the technique. Intention of possible evolution of the technique to imaging spectroscopic ellipsometry is proposed.
|
|
|
Design and set up of a laboratory sample of a laser deflectometer for measurement of mechanical stress within thin films
Šustek, Štěpán ; Klapetek,, Petr (referee) ; Ohlídal, Miloslav (advisor)
This diploma thesis describes the design of a device for measuring stress in thin films – laser deflectometer, realization of its design and its experimental testing. The thesis is divided into five chapters. The first chapter deals with the stress in thin films and its influence on substrate – thin film system. The second chapter provides an overview of devices widely used for measuring stress in thin films and describes some their advantages and disadvantages. In the third chapter some design possibilities of the device are presented. The final solution of device called deflectometr is introduced in the fourth chapter. The last chapter includes the functional testing the device.
|
|
| |
|
|
The Shortest Graph's Pahts Finding
Jágr, Petr ; Ohlídal, Miloš (referee) ; Jaroš, Jiří (advisor)
The aim of this thesis is finding, comparing and implementation of algorithms for finding the shortest paths between each of pairs of nodes in a graph. For this task I use modifications of existing algorithms to achive the lowest time consumption of the computation. Modifications are established on Dijkstra's and Floyd-Warshall's algorithm. We also familiarize with Bellman-Ford algorithm.
|
|
|
The Official Website of Research Group
Blaheta, David ; Jaroš, Jiří (referee) ; Ohlídal, Miloš (advisor)
The contents of this bachelor's thesis consists in a development of a research group website according to the specified requirements of the proposer. The created web pages are constructed dynamically and provide the user a lot of amenities not only in the field of information acquisition but also in the field of the administrator's work. The thesis describes information technologies which was utilized for realization, PHP, MySQL, XHTML, CSS and JavaScript. Moreover, it describes functions implemented in the portal and the way of their implementation. Namely, these functions are the following: diary of events, administration of publications, creation of animations, sending news on an e-mail address, joint work with Mathcad etc. A part of the thesis contains user's and administrator's manuals with pictures from the programmed application. As an enclosure, an electronic medium is provided with the source codes of the entire application.
|
guest ::
