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Characterization of Secondary Created Structures in PN Junctions of Silicon Solar Cells
Šicner, Jiří ; Číp, Ondřej (referee) ; Navrátil, Vladislav (referee) ; Koktavý, Pavel (advisor)
This thesis describes the study and characterization of secondary created structures in PN junction of silicon solar cells. Secondary created structure is the term which means the structures created for the purpose of suppressing the negative influence of local defects and edges of the solar cell. This means in particular laser notches used to isolate the edges. Furthermore, the secondary created structure means modification defective area using focused ion beam milling. Theoretical part of this work deals with short introduction to the topic of solar cells. There are mentioned the physical nature of the solar cell and the technology associated with the issue of solar cells. Experimental section begins with a description of the experimental methods. For diagnostic methods were used both electrical (UI characteristics, noise characteristics) and optical methods (measuring local radiation - CCD camera, thermal imager, lock-in thermography). Furthermore, there was also used a scanning electron microscope (SEM) equipped with technology using Focused Ion Beam (FIB). Sequentially there are presented individual results of characterization of created structures by laser. These partial results are incorporated into a comprehensive methodology developed for characterizing laser-created structures. The experimental part is finished by a presentation of the results of the research use of focused ion beam technology for sputtering defective areas of solar cells.
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Monitoring of environmental parameters in buldings
Slovák, Martin ; Číp, Ondřej (referee) ; Václavík, Vlastimil (advisor)
Aim of work is project system for monitoring environmental parameters in buildings. Theoretical part of work deals with parameters, which will be monitoring, why we measure those parameters in buildings. And what devices can we choose to do it. Measurement channel describes from change of physical value to electric value, after that there is a correction to processing by microcontroller. And those values are sending by microcontroller to other processing. The best solution to distant transmission is probably ZigBee technology. Practice part of work is in keeping with theoretical part. There are some practical sensor connections, where is difference in output of sensor. It’s necessary to project connections of sensor and do their software services. There is a simple tool to programming microcontrollers, which is called CodeWarrior. In last part is solution of algorithm, which make net by ZigBee technology.
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The Three-Dimensional Digital Imaging Methods for X-ray Computed Tomography and Digital Holographic Microscopy
Kvasnica, Lukáš ; Číp, Ondřej (referee) ; Štarha, Pavel (referee) ; Chmelík, Radim (advisor)
This dissertation thesis deals with the methods for processing image data in X-ray microtomography and digital holographic microscopy. The work aims to achieve significant acceleration of algorithms for tomographic reconstruction and image reconstruction in holographic microscopy by means of optimization and the use of massively parallel GPU. In the field of microtomography, the new GPU (graphic processing unit) accelerated implementations of filtered back projection and back projection filtration of derived data are presented. Another presented algorithm is the orientation normalization technique and evaluation of 3D tomographic data. In the part related to holographic microscopy, the individual steps of the complete image processing procedure are described. This part introduces the new orignal technique of phase unwrapping and correction of image phase damaged by the occurrence of optical vortices in the wrapped image phase. The implementation of the methods for the compensation of the phase deformation and for tracking of cells is then described. In conclusion, there is briefly introduced the Q-PHASE software, which is the complete bundle of all the algorithms necessary for the holographic microscope control, and holographic image processing.
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Calculation of potentials and simulation of the behavior of calcium ions in Paul's electrical trap
Vadlejch, Daniel ; Oral,, Martin (referee) ; Číp, Ondřej (advisor)
This thesis deals with comparison of motional properties of calcium ion confined in Paul’s radiofrequency linear quadrupole trap between symetrical and asymetrical driving modes of the trap by numerical simulation. It compares these two modes especially with respect to minimization of ion’s micromotion. It also provides detailed analysis of trapped ion’s secular motion. Together with ion’s motional properties it shows obtained shapes of potential in ion trap in detail. Agreement of real behavior of trapped Calcium ion with numerical model is verified via experimental measurement of trapped ion’s secular frequencies. Thesis also summarizes and uses theoretical description of general features of radiofrequency quadrupole ion traps.
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Determination Accuracy of Measurement in Nanometrology
Šrámek, Jan ; Číp, Ondřej (referee) ; Tykal, Miroslav (referee) ; Jankových, Róbert (advisor)
The presented doctoral thesis deals with measurements of extremely small sizes in nanometrology using a touch probe, which constitutes a part of a three-coordinate measuring system. It addresses a newly developed method of exact measurements in nanometrology by touch probes. The aim of this work was to expand the measurement options of this device and design a methodology proposal for the measurement of small parts, including the determination of accuracy of measurement of this device when used in nanometrology. The work includes the new methodology for the calculation of uncertainty of measurement, which constitutes a keystone in determining the accuracy of measurement of a accuracy three coordinate measuring system (hereinafter only nano-CMM). The first part of the doctoral thesis analyzes the present situation in the area of evaluation of accuracy of measurement in very accurate length measurements. It defines and describes individual methods implemented in the determination of accuracy of measurement on the instrument nano-CMM. A great emphasis is placed on the methodology of the measurement uncertainty, which draws from the author’s experience as a metrologist working in the laboratories of the Department of Primary nanometrology and technical length, Czech Metrology Institute Brno (hereinafter only CMI Brno). The second part of the doctoral thesis focuses on the determination of accuracy of length measurement in nanometrology, using a large set of measurements that were carried out under the reproducibility and repeatability conditions. There is also described and tested a model procedure utilizing the Monte Carlo method to simulate the measuring system nano-CMM in order to extent the newly created methodology of the measurement of uncertainty using a touch probe on the instrument nano-CMM. A substantial part of this doctoral thesis provides a detailed evaluation of results obtained from experiments that were executed under the repeatability and reproducibility conditions, especially for the purposes of the determination of the uncertainty of measurement. In this doctoral thesis, the uncertainty of measurement is chosen to quantify the accuracy of measurement of the instrument nano-CMM. The final part of this thesis summarizes the knowledge obtained during the scientific research and provides its evaluation. For the methodology used to determine the accuracy of measurement in nanometrology, it also outlines the future development in the area of scientific research, including the practical use in metrological traceability and extremely accurate measurements for customers. Furthermore, it deals with the possible use of other scanning systems compatible with the instrument nano-CMM.
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Control of an interference-microscope optical stage based on the image phase
Kvasnica, Lukáš ; Číp, Ondřej (referee) ; Chmelík, Radim (advisor)
Digital holographic microscopy is an interferometric imaging technique, the principle of which is the off-axis image plane holography. The principle of this technique enables to reconstruct both the image intensity and the image phase from the output interferencesignal. The reconstruction can be carried out on the basis of a single image plane hologram. This leads to the possibility of a realtime image reconstruction. The speed of the reconstruction depends on the detection and the computing process. The aim of this diploma thesis is to develop user software for the control of the detection camera and for the image plane hologram reconstruction. The effort was to achieve the highest number of image reconstructions per time unit, with the maximum utilization of the data transfer between the camera and the computer.The next aim of this thesis is the stabilization of the optical table position. The method of stabilization is based on the image phase information, which is used for the control loop feedback between reconstructed image phase and the piezoelectric actuator placed inside of the optical table. Experimental results, which prove the functionality of the stabilization, are presented.
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Characterization and elimination of thermomechanical effects in interferometric length measurement
Řeřucha, Šimon ; Holá, Miroslava ; Lazar, Josef ; Mikel, Břetislav ; Číp, Ondřej
Continuous efforts to develop dimensional measurements at both the nano- and macro-scale continue to present challenges in extending high-precision measurement procedures from the well-controlled experimental environment of a typically single measurement cycle to a constant-load production environment. In the field of laser interferometry, which is both a cornerstone of length metrology in general and an essential part of nanometrology, we have focused on long-term measurement stability (so-called zero-drift) in measurement scenarios and applications based on (mostly laser) interferometry. A well-characterized and compensated measurement zero-drift in such applications becomes more important both with applications in less controlled environments and with increasing measurement timeframes, such as long scans in microscopic nanometrology, long exposures in electron lithography, or interferometric reference calibrations with a larger number of calibration points or repetitions. The goal of the current research effort is to comprehensively investigate error effects and contributions to measurement uncertainty related to zero-drift in laser interferometry-based applications, with a particular focus on temperature effects (as these typically appear to be the dominant contribution) and approaches to suppress them. This effort involves several complementary directions.
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Design of a modular miniaturized apparatus for ion trapping
Jedlička, Petr ; Pham, Minh Tuan ; Grim, Jakub ; Čížek, Martin ; Čepil, Adam ; Slodička, L. ; Číp, Ondřej
We are developing a new experimental apparatus for laser cooling of trapped ions, focusing on high electric field homogeneity, modularity and small size. The apparatus allows measurements with Coulomb crystals and easy modification for different experiments. The high homogeneity trap is created by electrospinning, while the modularity allows for the exchange of key parts. By miniaturizing the dimensions, we achieve a larger numerical aperture of the lens and a reduction in the size of the magnetic shielding. This portable apparatus offers new possibilities for ion studies and is promising for applications in satellite systems and reconnaissance satellites.
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Frequency references and dissemination
Hrabina, Jan ; Pravdová, Lenka ; Šarbort, Martin ; Čížek, Martin ; Holá, Miroslava ; Oulehla, Jindřich ; Pokorný, Pavel ; Lazar, Josef ; Číp, Ondřej
The work deals with an overview of research topics of the “Frequency references and dissemination” group, Department of Coherence Optics, Institute of Scientific Instruments, Czech Academy of Sciences. These topics include frequency locking of lasers by laser spectroscopy and high-finnese optical cavities, digital holography and optical frequency tranfers through fiber and free-space optical links.
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