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Surface analysis using low-coherence interferometry
Pikálek, Tomáš ; Novák, Jiří (referee) ; Buchta, Zdeněk (advisor)
This thesis deals with low-coherence interferometry, laser interferometry and its combination intended to be used for contactless surface analysis. It outlines theoretical background of laser interferometry and low-coherence interferometry and describes in detail interference fringe center detection techniques used in low-coherence interferometry and their implementation into MATLAB environment. All these techniques theoretically described were analyzed to evaluate their measurement accuracy, resistance to optical dispersion and computational complexity in order to choose the most appropriate technique to be involved into the experiment. Furthermore, the thesis describes design of an experimental setup for optical surface analysis combining laser interferometry and low-coherence interferometry. There are presented experimental results and its comparison with the reference measurement. Overall measurement uncertainty is calculated and discussed too.
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Active Angular Alignment of Gauge Blocks in Double-Ended Interferometers
Buchta, Zdeněk
This paper presents a method implemented in a system for automatic contactless calibration of gauge blocks designed at ISI ASCR. The system combines low-coherence interferometry and laser interferometry, where the first identifies the gauge block sides position and the second one measures the gauge block length itself. A crucial part of the system is the algorithm for gauge block alignment to the measuring beam which is able to compensate the gauge block lateral and longitudinal tilt up to 0.141 mrad. The algorithm is also important for the gauge block position monitoring during its length measurement.
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High-power lasers with reduced emission spectrum
Buchta, Zdeněk
The paper describes a pilot experiment of a white-light fringe analysis with a low-cost color CCD camera. The used detection technique employs the phase-crossing algorithm which identifies the zero optical path difference as the point where the phase difference between the red, green and blue part of the white-light interference fringe becomes equal to zero. The experimental setup is designed to be a crucial part of the complex system for automatic contactless diagnostic and calibration of gauge blocks.
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