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Preparation and characterization of SNOM probes
Robešová, Magdaléna ; Rovenská, Katarína (referee) ; Dvořák, Petr (advisor)
This Bachelor’s thesis is about the preparation of precision probes for Scanning Nearfield Optical Microscopy (SNOM) and its characteristics. Since SNOM probes influence the near electromagnetic field, the quality of their construction and their exact description is a key element for the valuable interpretation of measured data. The goal of this thesis is to grant literature research about SNOM, SNOM probes and their preparation process. Secondly, to produce and characterize the functional SNOM probes, which could then be used to detect optical interferences of Surface Plasmon Polaritons (SPPs).
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Phase imaging below the diffraction limit
Nečesal, Daniel ; Bouchal, Zdeněk (referee) ; Dvořák, Petr (advisor)
Tato diplomová práce se zabývá konstrukcí interferenčních zařízení pro výzkum měření fáze světla na mikro-strukturách a fáze plazmonů na nano-strukturách. V první kapitole je vybudován teoretický základ pro optiku a nano-fotoniku používané v budoucích kapitolách. Následně je popsána interference vln a jejich praktické použití pro prolomení difrakčního limitu pomocí holografie plazmonů. Prvním experimentální sestavou je Machův-Zehnderův holografický mikroskop. Je popsán způsob, jak ho sestavit z běžně dostupných součástek a jak je navržen ovládací software k jeho používání. Následně jsou popsány výsledky naměřené pomocí tohoto zařízení. V poslední kapitole se zaměříme na sestavení holografického SNOM přístroje pro studování plazmonů a jejich interference. Nejdříve popíšeme základní princip a navržení softwaru pro automatizaci měření, pro zrychlení vědeckých postupů. Nakonec předložíme výsledky měření mikroskopu.
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Interaction between SNOM tip and near-field
Krpenský, Jan ; Kvapil, Michal (referee) ; Dvořák, Petr (advisor)
Interaction between a probe for scanning near-field optical microscopy (SNOM) and near electromagnetic field is a fundamental problem, with its solution being a necessary condition for the correct interpretation of experimental data. This bachelor's thesis is aiming to thoroughly describe this problem and by precise manufacturing of our own SNOM probes help to reach solution of this problem. For this purpose, the detection of near-field generated by interference of surface plasmon polaritons (SPP) on square shape nanostructures is being used. This study has proven the dependence of SNOM probe sensitivity to near-field components on the size of a SNOM aperture.
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Nanophotonics
Dvořák, Petr ; Rezek, Bohuslav (referee) ; PhD, Jakub Dostálek, (referee) ; Šikola, Tomáš (advisor)
This thesis deals with an experimental research of the surface plasmon polaritons (SPPs) using Scanning Near-field Optical Microscopy (SNOM). The first chapter provides theoretical background and a description of most of the physical phenomena and relevant dependencies studied in this work. These dependencies include the dependence of the resulting SPP image on homogeneity, polarization, wavelength and phase of the illumination, on the geometry of the interference structures and on the tilt of the sample with respect to the illumination. Further, this work presents a new experimental method which, using the numerical simulations or SNOM measurements, allows to estimate the sensitivity of SNOM probe to detect the individual electric intensity components of the near-field. At the end of the thesis, the work presents a new microscopic technique which enables a 3D quantitative imaging of phase distribution above the plasmonic metasurfaces.
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Use of a special optical fiber in an electron microscope chamber
Černek, Ondrej ; Konečný, Martin (referee) ; Pavera, Michal (advisor)
This bachelor thesis is concerned about the modification of vacuum chamber of the Scanning Electron Microscope VEGA developed by TESCAN Brno s.r.o. in order to implementation of Scanning Probe Microscope. Moreover, it is dedicated to development of apparatus for using hollow optical fiber allowing the guidance of light and various gases on the sample surface placed in the vacuum of electron microscope. By using the hollow optical fiber as a probe of Scanning Probe Microscope, it is possible to work with a tip with specific properties. A brief introduction to Scanning Electron Microscopy and Atomic Force Microscopy is presented in the theoretical part. Furthermore, there is a technique of using optical fibers in Scanning Near-field Optical Microscopy described. Also a problem of vacuum systems, gas flow through the pipe and technique of Gas Injection System is introduced. In the construction part, there are initiated steps in the development of the vacuum chamber and the apparatus allowing the guidance of hollow optical fiber into the chamber of microscope. The experimental part presents the result of measurements obtained by probe of Scanning Probe Microscope with modified optical fiber and gas transmissivity of hollow optical fiber.
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Local Isolation Of Microscale Defective Areas
In Monocrysline Silicon Solar Cells
Gajdos, Adam
This article is aimed on characterization of silicon solar cells microstructural inhomogeneities. To detect inhomogeneity or imperfection, reverse biased current voltage (I-V) measurement is used. These imperfections in some cases may cause avalanche type of breakdown, that can be visible in I-V curve. Therefore, the fact that certain imperfections emit light is used for localization needs. Raw localization is provided by electroluminescence (EL) method. Near-field scanning microscopy (SNOM) combined with photomultiplier tube is used for microscale localization. Both methods are done in reverse bias. Isolation of inhomogeneity by focused ion beam (FIB) is avoiding leakage current flow through it.
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Luminescence of semiconductors studied by scanning near-field optical microscopy
Těšík, Jan ; Klapetek, Petr (referee) ; Křápek, Vlastimil (advisor)
This work is focused on the study of luminescence of atomic thin layers of transition metal chalkogenides (eg. MoS2). In the experimental part, the work deals with the preparation of atomic thin layers of semiconducting chalcogenides and the subsequent manufacturing of plasmonic interference structures around these layers. The illumination of the interference structure will create a standing plasmonic wave that will excite the photoluminescence of the semiconductor. Photoluminescence was studied both by far-field spectroscopy and near-field optical microscopy.
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Preparation and testing of SNOM probes
Bobek, Juraj ; Pavera, Michal (referee) ; Spousta, Jiří (advisor)
The area of research that deals with surface modification and preparation of nanostructures is still very unexplored. And only a little contribution to this field is discussed in this bachelor thesis. Its goal is to manufacture and to test a probe made off hollow optical fibre that is used in Scanning Probe Microscopy. Optical fibre parameters in combination with proper and unique techniques allow the breakthrough off very interesting applications. It's worth mentioning the gas injection in the proximity of the surface of a sample (GIS) and thus its modification by use of electrons (FEBID), ions (FIBID) or laser beams.
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Field emission from the surface of highly ordered pyrolytic graphite
Knápek, Alexandr ; Pokorná, Zuzana
This paper deals with the electrical characterization of highly ordered pyrolytic graphite (HOPG) surface based on field emission of electrons. The effect of field emission, occurs only at disrupted surface, i.e. surface containing ripped and warped shreds of the uppermost layers of graphite. These deformations provide the necessary field gradients which are required for measuring tunneling current caused by field electron emission. Results of the field emission measurements are correlated with other surface\ncharacterization methods such as scanning near-field optical microscopy (SNOM) or atomic force microscopy. A simple method utilizing the field emission of electrons has been devised to characterize the sample surface. Electron and probe microscopies were used to determine the structure of both the bulk sample and the partially exfoliated shreds of the uppermost layers of graphite in locations where field emission is observed.
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