|
|
Location of vibration around the optical fiber
Dorazin, David ; Urban, František (referee) ; Čučka, Milan (advisor)
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.
|
|
|
Simulation of Mach Zehnder interferometer
Rozsypal, Filip ; Münster, Petr (referee) ; Čučka, Milan (advisor)
This bachelor thesis deals with the simulations of Mach-Zehnder and Michelson interferometer. These simulations are realized by VPIphotoncs and MatLab. The thesis also describes the optical and physical phenomena, the usage and the principle of operation of interferometers and results of measurements with validation of the basic work of both interferometers.
|
|
|
Fiber optic interferometry
Srnský, Petr ; Urban, František (referee) ; Čučka, Milan (advisor)
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.
|
|
|
Angular velocity measurement with fiber optic interferometer
Sodomka, Pavel ; Šedivá, Soňa (referee) ; Havránek, Zdeněk (advisor)
This bachelor thesis deals with the proposal and implementation of optic-fibre interferometer using the Sagnac phenomenon which measures the angular speed. In the theoretical part of this work, the possible interferometers are closer described and specified, base of wave interference, problems of the rotatory movement. The Sagnac phenomenon is explained and described here. Further the possible constructions of the optical-fibre interferometers for the measurement of the angular speed, including the described errors, which prevent the correct assembling and the implementation of the sensor. In the practical part of this work, the optical-fibre interferometer with the minimal balanced configuration. The individual optical and optical-fibre elements are selected and described to the given configuration, such as the source of radiation, polarizer, controller of polarization, divider, phase modulator, isolator, detector, optical fibre and optical-fibre coil. There is the specified and based problem which did not allow to successfully finish the assembled optical-fibre interferometer. In conclusion of this work there is the recommendation how to solve the caused problem.
|
|
| |
|
|
Optical setup for torque detected electron spin resonance spectroscopy
Kern, Michal ; Vetushka, Aliaksei (referee) ; Neugebauer, Petr (advisor)
Táto diplomová práca sa venuje vylepšeniu spektroskopu Torzne Detegovanej Elektrónovej Spinovej Rezonancie (TDESR) výmenou aktuálnej kapacitnej detekcie výchylky ohybného ramienka za optické metódy. Práca popisuje základy Elektrónovej Spinovej Rezonančnej (ESR) spektroskopie s dôrazom na TDESR a tému magnetizmu jednomolekulových magnetov. Následne je vysvetlená detekcia výchylky ramienka pomocou odrazu laserového zväzku a interferometrie. Všetky kroky nutné k skonštruovaniu spektrometra a jeho uvedenia do prevádzky sú podrobne popísané. Pomocou detekcie odrazu laserového zväzku sme úspešne získali vysoko kvalitné TDESR spektrá kryštálu jednomolekulového magnetu Fe4. Týmto meraním sme dokázali vhodnosť použitia tejto metódy a jej výraznú prevahu nad pôvodnou kapacitnou detekciou, najmä v oblasti kvality, rozlíšenia a rýchlosti. Zároveň sme na ďaľšie vylepšenie TDESR spektrometra navrhli a zostrojili zostavu využívajúcu na detekciu výchylky interferometer.
|
|
|
Dynamic laser interferometer
Chovaneček, Libor ; Drexler, Petr (referee) ; Fiala, Pavel (advisor)
The theme of this bachelor´s project is dynamic laser interferometer. The project is firstly focused on theory, where it explains the term of interference and principle of operation of interferometer on specific types of interferometers. Different types of lasers used in interferometers are mentioned there. The next part of this paper is focused on assemblage of interferometer with description of particular parts. There are mentioned two methods of signal processing. The last part deals with confirmation of proper functioning of measuring system.
|
|
| |
|
|
The femtosecond optical frequency comb based tool for spectral analysis of molecular absorbtion gases
Lešundák, Adam ; Šmíd, Radek ; Buchta, Zdeněk ; Mikel, Břetislav ; Lazar, Josef ; Randula, A. ; Číp, Ondřej
The spectral analysis of absorption of molecular gases belongs to very powerful methods for detection of concentration of gases in a tested sample. In case of the human breath it consists of hundreds of molecules of gasses and their concentrations are known as biomarkers. An increased concentration of more of them indicates certain diseases or symptoms. The presenting work covers a pilot experiment where femtosecond pulse probe laser and a detection chain based on cross-correlation makes an analysis of the specimen of the absorption gas. In the pilot experimental set-up the detection part utilizes a Michelson interferometer with movable measuring mirror. We developed a novel digital processing method for precise stabilization of the speed of the mirror during measuring process. The caught optical signals are calculated by the fast Fourier transform from the time to wavelength domain. The first caught spectra of the femtosecond beam passing trough the specimens show absorption lines of one isotope of acetylene which was tested as the first sample. The work proofed positive the possibility of using the femtosecond laser for detection of broadband absorption spectra in the infrared region.
|
|
|
Laser interference nano-comparator for length sensor calibration in nanometric scale
Číp, Ondřej ; Mikel, Břetislav ; Čížek, Martin ; Šmíd, Radek ; Buchta, Zdeněk ; Lazar, Josef
In the work we present new laser measuring system for precise calibrations of length measuring transducers. This gauge is called nano-comparator because the resolution of the positioning of the measuring probe is in order of nanometers. The gauge works fully self-controlled and it is equipped by control software which is able to calibrate wide area of transducers. We put main stress to compensating of thermal dilatation of the gauge body and to eliminating of imperfection of linear guide ways which are used for positioning of the testing probe of the gauge. The work presents the first records of scale calibration of an incremental transducer.
|
guest ::
