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Dispersion measurements of optical transmissions.
Motúz, Rastislav ; Urban, František (referee) ; Filka, Miloslav (advisor)
This thesis firstly theoretically describes phenomena which appear in optical fiber transmission. The theoretical part of the thesis deals with linear and non-linear phenomena, and later on proceeds to dispersions with a more significant effect on the optical transmission quality. It puts polarization to the centre of the phenomenon called Polarization mode dispersion (PMD), which is the main object of our interest. It leads to a deep PMD description from the point of view of polarization states, limit values, compensation methods, and methods of measurement. The practical part of this thesis deals with a draft of PMD measurement via Fixed Analyzer method. For the purposes of this measurement, we used the optical spectral analyzer MS9740A. In order to compare measured values, the proposed idea then proceeds to the reference measurement by using a modular platform EXFO FTB--200 in combination with CD/PMD module EXFO FTB-5700. Results of measurements have been evaluated for the limit values defined by the standard. In the last chapter of this thesis, the reference measurements are compared to the Fixed Analyzer method. All the advantages and disadvantages of individual measurement methods are identified at the end of this chapter too.
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Solving problems of CD and PMD in optical networks
Motúz, Rastislav ; Šifta, Radim (referee) ; Filka, Miloslav (advisor)
The aim of this bachelor’s thesis is to analyse dispersions which are affecting a high-speed transfer in optical systems. It is focused on chromatic – CD and polarisation mode – PMD dispersion. It is devoted to definitions, limit values, methods of measurements and compensation methods against disturbance to the final quality of transmission. The thesis is divided into the three-chapter long theoretical part and the practical part which contains two chapters. The results of the extensive experimental measurements done by CD/PMD tester – modular platform EXFO FTB-200 are stated in the practical part and partly in the Appendix too. The output of the measurement confirms the theoretical assumptions stated in the theoretical part and thus proves the aim of the thesis to be achieved.
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Utilization and Suppression of Birefringence Phenomena in Optical Fiber Sensory Applications
Motúz, Rastislav ; Hudcová, Lucie (referee) ; Vlček, Čestmír (referee) ; Drexler, Petr (advisor)
The thesis deals with integral and distributed optical fiber sensors of electric current. In the area of integral sensors the analysis is performed by Jones matrix calculus and the simultaneous influence of induced circular and undesired linear birefringence using an ortho-conjugation retroreflector. Furthermore, the proposed conjugation loop variant using half-wave phase retarders is analyzed. The theoretical conclusions are confirmed by simulation and experimental measurement. In the field of distributed fiber optic sensors, analysis and simulation for the detection of plasma currents in thermonuclear fusion reactors, based on the POTDR technique, is performed. An improvement procedure is proposed for circular-shaped vacuum vessel reactors. Plasma current detection procedure in divertor-type reactors have been newly designed and simulated to investigate the effect of the OTDR detector noise on plasma current detection accuracy.
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The Otdr Detector Noise Effect Of The Plasma Current Detection In Tokamak-Type Fusion Reactors
Motuz, Rastislav
This paper presents a theoretical analysis dealing with the plasma current measurement in tokamaks. A Polarization Optical Time-Domain Reflectometer (POTDR) setup was used, where the general case of non-uniform magnetic field distribution along the sensing fibre takes place. As a sensing medium, a low birefringent fibre has been chosen. The work is based on the numerical simulations in therms of the Jones formalism and takes into account the OTDR detector noise reflecting the measurement error as a function of the plasma current. The measurement performance is evaluated for an ITER-relevant sensor configuration. Simulation results reveal that for plasma currents from the range of 0 to 1 MA, the signal-to-noise ratio (SNR) of 6 dB complies with the ITER requirements. Subsequently, the SNR level of 4 dB satisfies the plasma current range of 1 to 20 MA. The SNR level of 6 dB is achievable in modern POTDRs.
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Utilization and Suppression of Birefringence Phenomena in Optical Fiber Sensory Applications
Motúz, Rastislav ; Hudcová, Lucie (referee) ; Vlček, Čestmír (referee) ; Drexler, Petr (advisor)
The thesis deals with integral and distributed optical fiber sensors of electric current. In the area of integral sensors the analysis is performed by Jones matrix calculus and the simultaneous influence of induced circular and undesired linear birefringence using an ortho-conjugation retroreflector. Furthermore, the proposed conjugation loop variant using half-wave phase retarders is analyzed. The theoretical conclusions are confirmed by simulation and experimental measurement. In the field of distributed fiber optic sensors, analysis and simulation for the detection of plasma currents in thermonuclear fusion reactors, based on the POTDR technique, is performed. An improvement procedure is proposed for circular-shaped vacuum vessel reactors. Plasma current detection procedure in divertor-type reactors have been newly designed and simulated to investigate the effect of the OTDR detector noise on plasma current detection accuracy.
|
|
|
Solving problems of CD and PMD in optical networks
Motúz, Rastislav ; Šifta, Radim (referee) ; Filka, Miloslav (advisor)
The aim of this bachelor’s thesis is to analyse dispersions which are affecting a high-speed transfer in optical systems. It is focused on chromatic – CD and polarisation mode – PMD dispersion. It is devoted to definitions, limit values, methods of measurements and compensation methods against disturbance to the final quality of transmission. The thesis is divided into the three-chapter long theoretical part and the practical part which contains two chapters. The results of the extensive experimental measurements done by CD/PMD tester – modular platform EXFO FTB-200 are stated in the practical part and partly in the Appendix too. The output of the measurement confirms the theoretical assumptions stated in the theoretical part and thus proves the aim of the thesis to be achieved.
|
|
|
Dispersion measurements of optical transmissions.
Motúz, Rastislav ; Urban, František (referee) ; Filka, Miloslav (advisor)
This thesis firstly theoretically describes phenomena which appear in optical fiber transmission. The theoretical part of the thesis deals with linear and non-linear phenomena, and later on proceeds to dispersions with a more significant effect on the optical transmission quality. It puts polarization to the centre of the phenomenon called Polarization mode dispersion (PMD), which is the main object of our interest. It leads to a deep PMD description from the point of view of polarization states, limit values, compensation methods, and methods of measurement. The practical part of this thesis deals with a draft of PMD measurement via Fixed Analyzer method. For the purposes of this measurement, we used the optical spectral analyzer MS9740A. In order to compare measured values, the proposed idea then proceeds to the reference measurement by using a modular platform EXFO FTB--200 in combination with CD/PMD module EXFO FTB-5700. Results of measurements have been evaluated for the limit values defined by the standard. In the last chapter of this thesis, the reference measurements are compared to the Fixed Analyzer method. All the advantages and disadvantages of individual measurement methods are identified at the end of this chapter too.
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