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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Optovláknová interferometrie / Fiber optic interferometry

Srnský, Petr January 2017 (has links)
The aim of the diploma thesis is theoretical analysis of optical fiber sensory sensing using coherent and incoherent interferometry, creation of simulation models of interferometers and their practical measurement. The first part deals with the description of basic physical principles and interferometers. In the second part the thesis deals with the description and design of optical microphones, which are based on the principles of physical interferometers Michelson and Mach - Zehneder interferometer. Both models are simulated in the VPIphotonics simulation environment. In the third part of the thesis, both models are assembled and measured. The last part of the thesis presents the differences between the interferometers and the results of the measurements.
2

Soustava Fabry-Perotova a Michelsonova interferometru pro měření délek s femtosekundovým laserem / The system of Fabry-Perot and Michelson interferometer for length measurement with a femtosecond laser

Vémola, Tomáš January 2011 (has links)
The thesis deals with a design of a comparing interferometer. It concerns a setup of two interferometers, one of them is a Michelson and another a Fabry-Pérot type. This set-up is made to compare results of length measurements simultaneously performed by each of them. In the Theory, basic principles of Michelson and Fabry-Pérot interferometers are described. A special attention is paid to an innovative method of length measurement with tunable lasers and optical frequency comb. In the Practical Part, so-called Pilot Experimental Setup is described. It is a prototype that has been used to perform basic experiments on comparing of the two above mentioned methods. Based on experimental results and practical experience with the Pilot Experimental Setup, a Final Setup is designed. It comes in a form of a stand-alone instrument.
3

Měření velmi malých výchylek pomocí optovláknového interferometru / Measurement of very small displacements with fiber-optic interferometer

Vybíral, Dominik January 2020 (has links)
This master's thesis is focused on optical methods of measurement of very small dynamic displacements. Principles of interfermeters with picometer resolution including Fabry-Pérot interferometer are discussed and an integration using this interferometer was designed. Parasitic influencers of Fabry-Pérot interferometer were described as well as signal processing methods for interferometer's output signal. An interferometric meter for measurement of dynamic displacement was designed with frequency range of several kHz. These parameters are achieved under condition of photonic crystal layer placed on measured sample.
4

Kalibrace koherenčního rastrovacího interferometru Talysurf CCI / Calibration of Talysurf CCI coherence scanning interferometer

Varava, Anastasia January 2017 (has links)
This master’s thesis deals with calibration of a coherence scanning interferometer Talysurf CCI Lite. Basic terms related to surface texture evaluation were described along with selected profile and areal surface texture parameters. The working principle and design of the calibrated instrument were explained. Manufacturer’s calibration procedure was analyzed in relation to the definition of calibration in the International vocabulary of metrology. Further calibration steps leading to calculation of measurement uncertainty were presented. Last but not least, measurement uncertainties of areal surface texture parameters Sq and Sz were evaluated. The procedures and results described in this thesis may contribute to wider use of non-contact surface texture measuring instruments.
5

Využítí Michelsonova interferometru pro detekci optického signálu a měření malých odchylek polohy / Optical signal detection and maesurement of low deflections using the Michelson interferometer

Kováč, Petr January 2008 (has links)
The dissertation is concerned with the description and utilization of interference of two coherent optical rays. In addition, the conditions of coherence and its connections with the occurance of interference are discussed. Michelson's interferometer is used for the practical utilization of the interference effect. The possibility of measuring relatively small changes is demonstrated - deviation of piezocrystal, measurement of the coherent length of optical source and measurement of the index of refraction of tramsparent materials. The manner of optical coherent detention and its utilization in optical communication systems is indicated. After demonstration of the principle was carried out the measuring of detection of optical signal modified by the external modulator.
6

Lokalizace vibrace v okolí optického vlákna pomocí interferometrického senzoru / Location of vibration around the optical fiber

Dorazin, David January 2018 (has links)
This diploma thesis solves possibilities of utilization optical fiber as sensor. At the beginning, basic division of this sensors is desribed, their principles and usage. Then the thesis is focused on distributed sensors based on the interference of the light, interferometers. This optic fiber interferometers are described, mainly their modifications for detection and localization of vibrations along optical fiber. Significant part of the thesis deals with dual Mach--Zehnder interferometer. This interferometer is theoreticaly desribed and simulated in Matlab. Further the thesis deals with development of two aplication in Matlab software. One application is for simulation and theoretical computation of dual Mach--Zehnder interferometer. Second application serves for signal processing of acquired data that are measured on this interferometer. At the end of the thesis, dual Mach--Zehnder interferometer is designed and build in laboratory enviroment and executed measurement and localization of vibrations using this interferometer.
7

Zpracování signálů z optovláknových senzorů / Processing of signals from fiber optic sensors

Sikora, Vojtěch January 2018 (has links)
First two chapters of this paper deals with the division of optical fiber sensors, digital signal processing and includes price comparison of four experimental sensors. In chapter three analysis, description and evaluation of measurment has been demonstrated on Mach - Zehnder interferometer. Last chapter is about application for signal analysis from vibration sensors. Description contains snippets from source code and graphical user interface. This paper includes three fields - fiber optics, digital signal processing and creation of application - and thanks to them it provides solid basis for study of optic fiber sensors.
8

Využití dat dálkového průzkumu Země pro určování vodní hodnoty sněhu / Use of remote sensing data for snow water content determination

Špátová, Zuzana January 2010 (has links)
Use of remote sensing for snow water content determination Abstract The aim of this diploma thesis is an integration of remote sensing to snow water equivalent measurement in Czech Republic conditions. The summary of present information of snow parameters retrieval is presented. For snow water equivalent obtaining, radar differential interferometry technique was chosen. The technique was carried out with seven ERS-2 radar images. The result of processing was finished after coherence images creation because of low coherence value at all interferometric pairs. The low coherence values did not enable next processing. Terms of the negative result are discussed. In the second part of the thesis, connection between snow characteristics and radar backscattering is searched. Dependence between snow moisture and backscattering is demonstrated. Factors, which impact values of backscattering and correlation with snow parameters, are discussed. In order to obtain snow water equivalent, the processing of remote sensed data was carried out for the first time in Czech Republic region. Therefore the negative result is still valuable information. Keywords: snow cover, snow water equivalent, remote sensing, radar interferometry
9

Testování technologie on-the-fly přístrojem LaserTRACER / Testing technology on-the-fly instrument LaserTRACER

Vala, Michal January 2017 (has links)
This diploma thesis describes realization and testing on-the-fly measurement using tracking interferometer. This measurement enables to achieve higher amount of measured points and decrease time of machine tool calibration. Calibration and verification values of machine parameters, as well as time of measurement and other details of this method are compared with results of conventional method called trigger. To evaluate the quality of volumetric compensation created from calibration values, we use verification measurement of circular interpolation.
10

Fázové zobrazování pod difrakčním limitem / Phase imaging below the diffraction limit

Nečesal, Daniel January 2020 (has links)
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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