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Wavefront sensor
Škaroupka, David ; Jákl, Petr (referee) ; Dostál, Zbyněk (advisor)
When the light passes through optical elements it can cause deformation of wavefront light due to the damage of materials and optical aberrations. The deformation leads to unprecise imaging and deformation of an image. The diploma work mentions wavefront sensing techniques which are important for determination inappropriate errors of optical elements and the specification of their properties. The purpose of the master's thesis is to suggest and investigate wavefront sensing methods after the light passes through the optical element while using the digital micromirror device. The work deals with the topic of wavefront aberrations and geometric optical defects of optical elements. Different kinds of commercial products determined for wavefront sensing are described too.
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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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Microscope for alignment of the optical fibers
Hekrlová, Kateřina ; Jákl, Petr (referee) ; Dostál, Zbyněk (advisor)
The demountable splicing of optical fibres uses different types of connectors which ensures accurate position of connected fibres. If the optical fibres are aligned in free space, a view from two perpendicular viewing directions is necessary for a maximum aligning accuracy. The method of direct monitoring of optical fibres provides this possibility however, it is necessary to use two imaging systems. This problem can be solved by a special microscope, which is designed in this thesis. The microscope can visualize the alignment of optical fibres from two mutually perpendicular directions by moving the objective lens and inclined mirror. The diploma thesis also describes the procedure of designing an optical simulation of the connection of optical fibres. Based on it, the microscope is designed, adjusted and tested with various optical fibres.
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Optical tweezers for coherence-controlled holographic microscope
Straka, Branislav ; Jákl, Petr (referee) ; Dostál, Zbyněk (advisor)
In the master's thesis, there has been described and explained the principle of operation of the second generation coherence controlled holographic microscope (CCHM2) designed at the Brno University of Technology. There has also been listed theoretical description of the operation of the optical trap, together with the calculation of the forces acting on it, ways of measuring the stiffness of the optical trap and the principle of~creating a time-shared optical traps. The optical tweezers forming a separate module connectable to CCHM2 was designed. Simulation and optimization of parameters of the optical system, mechanical design, manufacturing documentation, current source to power the laser diode which allows to control the diode output power by the controller card connected to the PC was designed. The galvano-optics mirror angle is controlled by the PC card too. The optical tweezer has been designed, manufactured and tested in conjunction with the CCHM2.
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New Generation of a Coherence-Controlled Holographic Microscope
Slabý, Tomáš ; Novák,, Jiří (referee) ; Jákl, Petr (referee) ; Chmelík, Radim (advisor)
This doctoral thesis deals with design of a new generation of coherence-controlled holographic microscope (CCHM). The microscope is based on off-axis holographic configuration using diffraction grating and allows the use of temporally and spatially incoherent illumination. In the theoretical section a new optical configuration of the microscope is proposed and conditions for different parameters of the microscope and its optical components are derived. The influence of different sources of noise on phase detection sensitivity is studied. In the next section design of experimental setup is described and automatable adjustment procedure is proposed. Last section describes experimental verification of the most important optical parameters of the experimental setup. When compared to previous generation of CCHM, the newly proposed configuration uses infinity-corrected objectives and common microscope condensers, allows more space for the specimens, eliminates the limitation of spectral transmittance and significantly simplifies the adjustment procedure so that automation of this procedure is possible.
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Possibilities of three-dimensional imaging in transmitted-light holographic microscope
Sládková, Lucia ; Jákl, Petr (referee) ; Kolman, Pavel (advisor)
Digital holographic microscopy (DHM) is noninvasive method for obtaining images even from samples with low contrast. Nowadays DHM design makes it possible to illuminate sample by broad light source, halogene lamp. Broad light source is displayed in the front focal plane of condensor in such way, that Köhler illumination is achieved. Each point of the source corresponds to a plane wave in image field of objective, which illuminates the whole field of view, but from different direction. Position of the point determines the direction of illumination. In this reason, the microscope enables so reconstruct not only intensity, but also phase of object wave. New designed and constructed interchangeable pinhole aperture modify broad light illumination by rotation around the optical axis. Aperture is placed eccentrically considering the optical axis of microscope. Incidence of light beam on a sample would be under defined angle. After the reconstruction of taken phase images from individual angles of illumination should be possible to obtain three-dimensional structure of the sample.
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3D printed opto-mechanical devices
Šremrová, Vendula ; Dostál, Zbyněk (referee) ; Jákl, Petr (advisor)
Optomechanical components are widely used in many optical experiments. This diploma thesis deals with design and manufacturing optomechanical components using 3D print technology. These are cheaper alternatives of commercial devices. In addition to 3D printed parts, minimum number of other components are used to assemble functional devices. Using simple experimental setups, the manufactured components are evaluated and compared with commercially available ones. The results show that they can be used in applications where high accuracy is not required. The second part is devoted to the design and manufacturing of a polarimeter as a mechanism combining electrical and mechanical components with 3D printed parts. The polarimeter is used to measure some properties of polarized light.
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Preparation and analysis of fibre probes for holographic microendoscopy
Černá, Eliška ; Průša, Stanislav (referee) ; Jákl, Petr (advisor)
This theses deals with the preparation and analysis of fibre probes for a holographic microendoscope. The fibres are specifically sanded and a reflective layer of aluminium or silver is applied on them by thin film deposition. The properties of these deposited layers are further examined and evaluated using AFM, profilometer and measuring apparatus to assess the reflectivity. The protocol describing the production of fibre-optic probes with optimal parameters for holographic microendoscopy is created from measured data. Such fibre probes could be beneficial in the diagnosis of neurodegenerative diseases such as Alzheimer’s or Parkinson’s disease.
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Multimode optical fiber based endoscopy
Jákl, Petr ; Tučková, Tereza ; Pikálek, Tomáš ; Stibůrek, Miroslav ; Ondráčková, Petra ; Cifuentes, Angel S. ; Šiler, Martin ; Uhlířová, Hana ; Traegaardh, Johanna ; Čižmár, Tomáš
Optical microscopy is a technique for microworld investigation using light waves scattered on particles in sample space. Its main disadvantage in the area of medicine, microbiology and neurology is its low penetration depth - it is very difficult to image structures deeper than approximately 1 mm inside tissue. Conventional endoscopes use refractive or GRIN lens with cross-section of several milimeters in diameter. Therefore, it is necessary to find less invasive probes to perform imaging in living organisms. Favourable alternative is to use multimode optical fiber probe with 100 micrometer diameter. This approach, however, requires advanced shaping of the wavefront in order to achieve diffraction limited imaging.
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3D printed microscopes
Žáková, Veronika ; Jákl, Petr (referee) ; Dostál, Zbyněk (advisor)
Modular microscope building kits allow those interested in microscopy to get a hands-on introduction to the construction of a light microscope. For this reason, it would be appropriate to equip the laboratories of the Institute of Physical Engineering at Brno University of Technology with such a kit. The inspiration can be found in the open source project openUC2, which offers optical kits based on a combination of 3D printed and commercially available optical components. The aim of my work is to use the open source parts database and supplement it with my own designs that would enable the construction of specialized polarization and fluorescence microscopes. The first part of the thesis introduces light microscopy methods and the equipment that is essential for their proper operation. Next, the 3D printing methods that are applicable to the fabrication of the designed parts are summarized. Beyond the openUC2, the design of a Köhler illuminator, a motorized stage and a motorized objective slider based on commonly available parts are introduced. A transmission microscope, a reflective polarizing microscope and a light sheet microscope were designed based on the UC2 kit with my construction modules. The first two have been assembled and tested along with their control software.
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