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Passive optical networks WDM-PON
Havliš, Ondřej ; Šifta, Radim (referee) ; Münster, Petr (advisor)
The work deals with optical access networks, passive optical networks, especially WDM-PON. Features a modern solution to connect users to the optical access network using optical FTTx connections. Describes the different types of FTTx connections, their parameters and construction technology. Practical work is a practical application of theory for the development of various design and simulation of WDM-PON networks. Each proposal includes the construction of technical solutions optical access networks, the technology used and the balance of the reduced pricing WDM-PON network. The penultimate part of the work consists of design models simulated WDM-PON networks by the simulation program OptSim. The conclusion deals with the evaluation of individual design and simulation of WDM-PON networks.
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Optical switching and traffic grooming
Foldyna, Petr ; Havliš, Ondřej (referee) ; Horváth, Tomáš (advisor)
This bachelor thesis is about problematics of optimalization wavelenght usage in optical networks. First part theoreticaly explains optical networks and problems when using them, switching in optical networks and traffic grooming. In second part mathematical equations of given problems are realized and also simulations using GLPK are realized. From results of simulation resolutions are given and usage of methods in real networks is explained.
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Methods for searching and documenting optical cables
Havliš, Ondřej ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The purpose of this bachelor thesis is a description of searching for optical cables with metallic elements and EMS markers below the earth surface by suitable method and the possibility of recording and documentation of optical cables in a geographic information system ArcGIS. In the beginning there is a mention of an optical cable in particular of its the most important part, which is an optical fiber. Further there is the purpose what the optical fiber in the telecommunications world of techniques was developed for. Then there are the various advantages of the optical fiber described. This project also deals with the various methods of searching the optical cables using metallic elements. It is a called Galvanic and Inductive method, which are used to search for the optical cable by using the enclosed metallic lines, which, with the proper connection to a receiver, generates electromagnetic fields around. Another way to search the fiber optic cable is realized by the EMS markers. There are various types of passive electronic tags described. These electronic passive tags are manufactured in different color, which is used for marking the various branches of networks. There is the possibility of documentation of the optical cables by using ArcGIS geographic system from ERSI mentioned in the project. There is its structure and func-tion of individual subprograms in detail described. In the chapter GSM there is an analysis of operating principle of the system. At the end of this thesis the laboratory task is suggested. It describes the searching for fiber optic cable and the other metallic circuits by passive markers and iD markers.
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Optical amplifiers and their applications
Dvořák, Tomáš ; Havliš, Ondřej (referee) ; Münster, Petr (advisor)
The main purpose of this diploma thesis is to study of possibilities of optical amplification, ways of realization optical amplifiers and construction of operational EDFA amplifier . According to gained information and knowledge about optical amplifiers, the basic configuration of EDFA amplifier with posibility of connecting up to two EDFA modules, which uses erbium-dopped fibers for amplification, was made. There was also developed a 3D model of front control panel of the amplifier and placement of particullar items was planned. Next step was the construction of EDFA amplifier device and measuring of its parameters and features.
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Multiband fiber polygon for accurate time and coherent frequency transmission
Havliš, O. ; Vojtěch, J. ; Šlapák, M. ; Číp, Ondřej ; Čížek, Martin ; Hrabina, Jan ; Pravdová, Lenka ; Slodička, L.
The CESNET association, in cooperation with the Institute of Scientific Instruments of the Academy of Sciences of the Czech Republic (Institute of Scientific Instruments of the CAS, abbreviated ISI CAS), ČD Telematika and University Palacký in Olomouc (UPOL) Department of Optics built a multiband polygon on real optical routes . The multiband polygon is designed for two-way transmission of ultra-stable quantities, i.e. transmission of acurrate time and coherent frequency (T/F).
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Fragmentation-free ultrastable transfers through shared optical fibers
Vojtěch, J. ; Smotlacha, V. ; Havliš, O. ; Šlapák, M. ; Altmannová, L. ; Kundrát, J. ; Vohnout, R. ; Velc, R. ; Čížek, Martin ; Hrabina, Jan ; Řeřucha, Šimon ; Pravdová, Lenka ; Lazar, Josef ; Číp, Ondřej ; Kuna, Alexander ; Roztočil, J.
Fibre optics transfers of precise time and ultra-stable optical frequency are gradually becoming part of portfolio of network services of research and educational networks. These national infrastructures very often share fibres with regular data transmission, because of significant share of fibre cost rental on the Total Cost of Ownership (TCO). Situation is very similar in the Czech Republic, where there was more than 3000 km of ultra-stable transmissions within Czech e-Infrastructure, which itself runs over about 5800 km of dark fibre lines.
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Highly-coherent laser for precise optical frequencies dissemination
Pravdová, Lenka ; Čížek, Martin ; Hrabina, Jan ; Jelínek, Michal ; Řeřucha, Šimon ; Mikel, Břetislav ; Lazar, Josef ; Havliš, O. ; Altmannová, L. ; Smotlacha, V. ; Vojtěch, J. ; Velc, R. ; Číp, Ondřej
The paper presents a multipurpose laser with a very narrow spectral line, operating at a wavelength of 1540 nm and designed for cooled ions spectroscopy and the dissemination of precise optical frequencies over optical fibre links. The optical frequency of a commercial single-mode laser (NKT Photonics Koheras Basik) is spectrally narrowed to the level of several Hz using a high-quality optical resonator as an optical reference and an acousto-optic modulator as an active control element. The optical resonator is made of a low length thermal expansion coefficient material and is placed in a multi-shell vacuum chamber providing a stable operating environment. Optical frequency stabilisation uses PDH (Pound-Drewer-Hall) modulation and detection technique.
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Phase coherent link between ISI and BEV
Čížek, Martin ; Pravdová, Lenka ; Hrabina, Jan ; Lazar, Josef ; Číp, Ondřej ; Havliš, O. ; Altmannová, L. ; Smotlacha, V. ; Vojtěch, J. ; Pronebner, T. ; Aeikens, E. ; Premper, J. ; Mache, W. ; Niessner, A. ; Schumm, T.
The paper deals with the current state and the first experiments performed on a 232 km long cross-border phase-coherent line between ISI in Brno and BEV in Vienna. This line is the first operational segment of the planned network for mutual comparison of different types of optical atomic clocks between ISI (Ca +), BEV (Cs) and Atominstitut (Thorium) in Vienna. At all workplaces, local highly coherent lasers (spectral line width in the order of Hz or better) will be synchronized with the link output. This network of synchronized lasers will serve as a transfer medium for the mutual comparison of optical atomic clocks in individual laboratories.
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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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