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Stable optical frequency transfer between ISI and CESNET workplaces
Čížek, Martin ; Pravdová, Lenka ; Hucl, Václav ; Jelínek, Michal ; Hrabina, Jan ; Řeřucha, Šimon ; Mikel, Břetislav ; Lazar, Josef ; Číp, Ondřej ; Smotlacha, V. ; Havliš, O. ; Vojtěch, J.
The contribution reports on the current state of a 306km long experimental line for transfering stable optical frequency from a telecommunication band laser standard between ISI CAS (Brno) and CESNET (Prague). The bidirectional link uses a telecommunication fiber with a dedicated DWDM window of 1540-1546 nm.1540-1546 nm. In the Czech rep. this technology can be utilized currently in two fields: remote comparisons of optical frequency standards and remote callibration of instruments (optical spectral analyzers) in industrial applications that do not allow transporting the device to a specialized laboratory. The stability of the optical frequency transfer was evaluated. A long-term measurement of transport delay was conducted. \n
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Optical software defined networks
Janoušek, Adam ; Horváth, Tomáš (referee) ; Vojtěch, Josef (advisor)
The bacherol thesis „Optical SDN“ deals with the analysis of software-defined technology networks on the optical switch. Specifically, it focuses on remote manual switching and automatic switching based on surroundings. The aim of the thesis is description of technology, understanding the principle of software-defined networks, including the implementation of demostrative manual remote switching and automatic switching.
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Graphical user interface for sensing systems
Dejdar, Petr ; Vojtěch, Josef (referee) ; Münster, Petr (advisor)
Master thesis is focused on creating graphical user interface for the sensorical system based on Phase-OTDR. Theoretical part describes optical fibers, explains the principle of Bragg gratings, their production and their use in sensors. Methods of optical fiber attenuation and phase OTDR measurement are also described. Other part is focused on LabVIEW programming software and utilization of sensorical system and its components. Practical part deals with the user interface itself, which consists of two tabs. The first tab is designed for evaluation and display of measured data. The second tab is used to control and set up system components. Both of these tabs are further subdivided into other subtabs. Regarding the conclusion, further development of the program and options of hardware replacement for improving this sensorical system in the future will be discussed.
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Transmission of accurate time and stable frequency through the optical network
Girt, Lukáš ; Horváth, Tomáš (referee) ; Vojtěch, Josef (advisor)
Diploma thesis focuses on the theoretical analysis of precise time and stable frequency transfer. It describes what time and frequency is, their properites and options of their generation. Next part deals with different possibilities of time and frequency transfer especially using fiber optics. In the practical part equipment for analysing effects of temperature changes on precise time transfer is puted into operation. Arduino platform is used for monitoring temperature changes on fiber. For testing of frequency stability in variable temperature conditions of environmental chamber device is created using highly coherent laser.
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Seismic activity measurement using fiber optic sensors
Vaněk, Stanislav ; Horváth, Tomáš (referee) ; Vojtěch, Josef (advisor)
The aim of master's thesis is to get familiarized with the problems of measurement and analysis of seismic waves. Theoretical part deals with the description of seismic waves, especially their types, sources and properties. Attention was afterwards focused on the measurement systems of these waves, emphasis was placed on their principles and advantages. The practical part discusses methods of noise reduction and highlighting of significant events in measured data. At the end, individual methods are implemented into user-friendly graphical interface.
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