|
|
Possibilities of increasing the throughput of optical fiber industrial networks
Čičmanský, Tomáš ; Münster, Petr (referee) ; Filka, Miloslav (advisor)
Diploma thesis deals with problems of industrial networks using optical fiber as the main transmission lines. The task of the diploma work is to study and summarize the issues of industrial networks as well as the ways to increase their transmission capacity. In telecommunications and computer networks are generally used multiplexes, thanks to which we are able to achieve the desired transmission capacity. Consequently, the following work deals with the selection of the adequate solutions using described multiplexes as well as other transmission methods. The aim of the diploma work is to compare various renovation techniques of an old industrial network. Using this network as an example the work should demonstrate the individual problems and their solutions while considering different types of methods used. Based on the price, the performance and the difficulty to install other devices and transmission media we are able to select the appropriate solution for optical link.
|
|
|
Microbending fiber optic sensors
Švestka, Jiří ; Štohl, Radek (referee) ; Šedivá, Soňa (advisor)
This thesis deals with the influence microbending the transmitted signal at the bare optical fiber. Microbending influence on the transmitted signal is investigated in this work by changing the weight, power and water level in the tank by using this test fixture. The results of the experiments are proposed to enter the laboratory tasks to measure the impact microbending the transmitted signal in the subject line fiber-optic sensors (MOES).
|
|
|
Fiber joints and their protection
Galovič, Dominik ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
The bachelor thesis deals with the issue of optical fiber joining. The theoretical part describes the methods of optical fiber splicing, protection of optical splices and possible errors that affect the quality of the optical splice. Also described are methods for measuring important optical joint parameters, such as attenuation or reflection attenuation. An important part of the work is a description of the restoration of primary protection of spliced fiber. The theory is further applied in the practical part, where the attenuation of the optical links was measured using the mentioned methods. It also includes a comparison of the mechanical strength of optical splice and a joint formed by optical connectors. This knowledge is then applied in a proposal for minimizing the optical splice and proposals for restoring the primary protection of the optical splice was described.
|
|
|
Measuring methods of key parameters in optical networks
Balon, Jiří ; Reichert, Pavel (referee) ; Tejkal, Vladimír (advisor)
The main goal of the master’s thesis was to familiarize with optical networks dilemma and its measuring during fabrication. The whole thesis is divided into several parts where the first part deals with optic fiber dilemma. It describes its kinds, properties and also suggests a basic principle of optic signal dispersion using these fibers. It describes also optical network FTTx architecture (Fiber To The x). The second part of the thesis focuses on methods of measuring key parameters of optical networks. Is brings out the methods of measuring optical loss and dispersive influences. The last and final part in focused on creating a methodical manual for measuring these networks during its fabrication and verifying measuring methods stated in the theoretical part inside a real network. Measuring was implemented on an optical network of Masaryk University in Brno.
|
|
|
Design of a mirror collimator for a light beam outgoing from a silica fibres bundle of a circular cross section.
Vodák, Jiří ; Brillová, Kateřina (referee) ; Ohlídal, Miloslav (advisor)
Imaging spectroscopic reflectometry is an innovative method for studying optical properties of thin layers. This method allows as studying large areas of thin layers. Imaging spectrophotometer designed in The Institute of Physical Engineering was supposed to allow measurements along areas of about 25 mm x 25 mm. However this area was not achieved. To achieve desired dimensions of the area under study it is necessary to redesign the optical transmission setup between a source of monochromatic light and the imaging spectrophotometer.The old spectrophotometer design consists only of a mirror collimator not sufficient enough to collimate a rectangle shaped light beam on the output of the monochromator. The new design will consist of optical cable of silica fibers transforming the rectangle input light beam into a light cone which will be easier to collimate by a mirror collimator.
|
|
|
NG - PON technologies
Balon, Radek ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
The main object of the master thesis was to familiarize with optical networks, describe the latest current technology of passive optical networks and create a simple simulation of our chosen technology. This thesis was divided into several parts. The first part deals with passive network architecture. I illustrated the basic functional elements which are present in optical networks. I described the active elements and principles of data transmission in the distribution network. To conclude this chapter I described the different standards that are defined for the passive network. In second part I familiarized myself with key parameters and their adverse effect on the transmitted signal. Another part deals with the new technologies that are defined for the next generation of passive network NG-PON. I described the principles of data transmission in these networks and their advantages and disadvantages. The last part deals with creating custom simulations of technology defined by standard NG-PON using OptSim 05.02 Subsequently I have collated all the results of the various technologies and show the advantages and disadvantages of each.
|
|
|
Fiber-Optic Sensors
Dejdar, Petr ; Róka,, Rastislav (referee) ; Kyselák, Martin (referee) ; Münster, Petr (advisor)
Optical networks are continuously expanding and this creating space for the use of optical fibers for non-data transmissions. One of them is the use for sensing purposes, where optical fibers can be used to measure temperature, pressure, vibration, etc. In standard conditions or in conditions where the placement of conventional sensors is not suitable (increased humidity, radiation, lack of space, etc.).This paper is devoted to the comparison of technologies comparing sensing systems and describes their principle and their possible applications. Subsequently, the different systems are built and tested. Possible improvements are then proposed based on the measurements, where for the reflectometric system the advantages of using edge detection algorithms are quantified. For the polarization detectors, improvements are made using machine learning classification algorithms with classification success rates above 97 %. Detailed measurements of the sensitivity of optical fibers to acoustic vibrations in three different environments, with different path configurations, cables, vibration-damping materials, etc. are also described. These measurements proved the possibility of intercepting optical fibers using interferometric, reflectometric, and polarization systems, where the polarization system is proven to be the least sensitive and records only lower frequencies. Based on these measurements, a system for securing the physical layer of optical networks is then proposed, which is able to accurately distinguish the quiescent and cable manipulation states from the datasets we created.
|
|
|
Spectral characteristics measurement of single fibre optical transmission
Balon, Radek ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The main object of the bachelor´s thesis is show familiarize with optical networks and measuring when the fibres are connected to operating network. The whole thesis was separated into several parts. The first part was deals with optic fiber and properties, kinds of optic fibers, methods of propagation light inside fiber and important parameters, which has undesirable effects, such as optic loss and dispesive influences. Next part was concentrated on transfer technologies, which where used for data transmission in operating networks. We talked about differences between technologies and describe the monitoring system, which was used for measuring parameters in operating network. The last part was focused on own measuring. We was measured the parameters in operating network CESNET2 and influence of the signal after connect optic monitoring probe. Measuring was implemented on optical network of Masaryk University in Brno (ÚVT MU).
|
|
|
Fiber joints and their protection
Galovič, Dominik ; Dejdar, Petr (referee) ; Münster, Petr (advisor)
The bachelor thesis deals with the issue of optical fiber joining. The theoretical part describes the methods of optical fiber splicing, protection of optical splices and possible errors that affect the quality of the optical splice. Also described are methods for measuring important optical joint parameters, such as attenuation or reflection attenuation. An important part of the work is a description of the restoration of primary protection of spliced fiber. The theory is further applied in the practical part, where the attenuation of the optical links was measured using the mentioned methods. It also includes a comparison of the mechanical strength of optical splice and a joint formed by optical connectors. This knowledge is then applied in a proposal for minimizing the optical splice and proposals for restoring the primary protection of the optical splice was described.
|
|
|
Sol-gel synthesis of ternary ZnxTiyOz nanostructures for applications in solar cell technologies and photonics
Mrázek, Jan ; Nižňanský, Daniel (advisor) ; Pinkas, Jiří (referee) ; Pollert, Emil (referee)
The presented study deals with the sol-gel synthesis of nanocrystalline ternary phases of the general formula ZnxTiyOz, their characterization and potential application in photonics. Achieved results brings new fundamental knowledge about the processes leading to the formation of ZnxTiyOz nanocrystals from amorphous xerogels and gives novel information about structural and opto-electrical properties of prepared materials. Based on the presented results, most of all up-to-date reported ZnxTiyOz compounds with tailored nanocrystalline size and structure can be prepared as powders or thin films. Two sol-gel approaches based on the cluster process and direct heteronucleation were employed to prepare initial sol. Sols were optionally doped by Eu3+ ions to evaluate the effects of rare earth element to crystallization properties of formed compounds. In the first part of our study crystallization properties and structural evolution of thermally treated xerogels were analyzed. As a result a versatile method allowing the preparation of inverse spinel Zn2TiO4, cubic defect spinel ZnTiO3 and rhombohedral ZnTiO3 with tailored nanocrystal sizes was established. Initial composition and thermal annealing allow us to prepare selected ternary phase with tailored nanocrystal size ranging from tens of nanometers up to...
|
guest ::
