National Repository of Grey Literature 201 records found  beginprevious86 - 95nextend  jump to record: Search took 0.00 seconds. 
Long optical fibre routes influence on the polarizing state of light and uses it for powering polarization sensors
Panascí, Marco ; Grenar, David (referee) ; Filka, Miloslav (advisor)
This diploma thesis deals with the influence of long fiber optic paths on the polarization state of light and their use for powering polarization sensors. The aim of the diploma thesis was to design the arrangement of optical fiber components so that the polarization properties of light at the end of the path are further usable for sensory purposes. Four partial measurements with a long path (in a laboratory setting, laying in the ground, on a curtain, under the influence of external influence) and one measurement without a path under the influence of external influence were designed. The overall measurement results demonstrate that for the functional power supply of long-distance sensor systems, an existing single-mode fiber can be used (laid by laying in the ground), into which a light source for a given sensor system would be multiplexed. In the discussion, all types of measurements are analyzed and compared with each other. Finally, the overall result is summarized and applications are described in which such a sensor system could be used.
Assemblying effect on cable lines quality
Dočkal, Martin ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
In the first part is explained what actually a structured cabling is. Its beginning, from what and why it was created. Its history when at the beginning were applied unbalanced coaxial cables, those were later replaced by balanced cables. In cabling for TVs are still used coaxial cables. Balanced cables are according to type named UTP, STP, FTP, and so on. Whit growing popularity of this type of cabling and its wide spread application was necessary to set some rules, standards, specifications and demands, how to build up the cabling from project to realization. According to these rules is the system built so there are strict rules for length of subsystems and interfaces and the whole appearance of the structure cabling. Next important point is projecting of cabling that is related to the previous points and when it’s finished, we should strictly follow it. With the project is closely connected characteristic of this cabling as attenuations, cross-talks and other transmission parameters which are measured in the practical part. In the second part is spoken about all the parts of which the structured cabling consists - metallic and optical connecting elements and cables. There are also mentioned their mechanical, electrical and transmission features. In the third part is described influence of man on the quality of structured cabling and the most common causes of lower quality and the ways how to prevent this from happening and how to manipulate with cabling not to destroy it. The final (fourth) part considers the measurement. There are measured qualities of metallic wires as the attenuations, delay, cross-talks on the near- and far-end, impedance and resistance. To all the features are mentioned schemes of the measurement on the twisted pairs. The measurement is divided into two parts. In the first part are measured five types of balanced cables of different length, category and damage influencing quality of these cables. In the second part is measured one balanced cable if it’s corresponding with category 5 for that t was made and if it would be possible to use it also for higher category 6. Values are tabularly sorted in tables.
Optical fibres and their polarization effect
Klesnil, Ondřej ; Dostál, Otto (referee) ; Filka, Miloslav (advisor)
This project describes the fundamental concepts and basic theory of polarization mode dispersion (PMD) in optical fibers. There are described basic the relation between Jones vectors and Stokes vectors, rotation matrices, the definition and representation of PMD vectors, the laws of infinitesimal rotation. After the introduction the first conception with bases of polarization mode dispersion (PMD) in optical fibers, they have become an important body of knowledge basic for the design of high-capacity optical communication systems. PMD effects are linear electromagnetic propagation phenomena occurring in so-called “single-mode“fibers. Despite their name, these fibers support two modes of propagation distinguished by their polarization. Because of optical birefringence in the fiber, the two modes travel with different group velocities, and the random change of this birefringence along the fiber length results in random coupling between the modes. With current practical transmission technology the resulting PMD phenomena lead to pulse distortion and system impairments that limit the transmission capacity of the fiber. I describe different ways of measuring PMD in optical fibre, PMD compensation techniques and analyse PMD results in optical fibres.
The Design of FTTH Network
Zorgani, Nagib Youssef ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
The aim of this thesis is to explain the problems of optical access networks with wavelength division multiplexers, main purpose is to demonstrate the difference between theoretical and real measurement. The work is divided into several thematic areas. The introduction outlines the basic of telecommunications, fiber optics lasers, single mode, multimode, lasers fibers cables & cores, splitters division multiplexing system, there are known solutions discussed fundamental wavelength multiplexes and their possible combinations. The following chapter deals with the active elements such as AON, PON, which are essential part xWDM systems such as optical lasers, detectors and amplifiers. Another chapter focuses on passive elements, which form a key part of the wavelength multiplex. Methods of measurement of WDM/PON networks are discussed in the following part. The next section describes the topology used active and passive optical networks. The penultimate part of the work consists of architecture & technology of xWDM such as GPON and WDM-PON networks and comparing their transmission parameters. The final part of the paper presents the results of practical experimental measurements of optical access networks with wavelengths division multiplex while these results are compared with the theoretical output & methods of Optical lost test, OTDR & LSPM, with advantage & disadvantage of every methods. The second part of practical is the draft to the connection resident housing units of 30 houses, boarding-house (10 rooms) and 2 shops, 20 km distant from exchange. With comparing the possibilities of two options- passive and active optical network- PON system – WDM- Wave multiplex. Suggest the possibility of measuring and monitoring the created network.
Methodology for FTTH optical network measurement
Gajdoš, Jaroslav ; Reichert, Pavel (referee) ; Filka, Miloslav (advisor)
The main topic of this master thesis is a FTTH measurement methodology of optical networks and its specific features 9 compared with other measurement methodologies. Also, the use of the FTTH measurement methodology: an example of measurements of a passive network with splitter 1:8 and analysis of the results of these experimental measurements. The first part of the thesis concerns itself with the description of optical networks and characteristics and features of the FTTH networks. A detailed description of the passive optical networks is provided: e.g. the optical network unit ONU, the optical line termination OLT, and, most importantly, the passive optical splitter. The wavelength division multiplex 9 WDM 9 which is used in passive optical networks is also described in detail. The chapter on measurement methodologies focuses in detail and provides many examples of currently used measurement methodologies of these networks. The best results are currently achieved with the OTDR methodology. The second part of the thesis concentrates on the description of the measurement of a passive optical network with splitter 1:8 using the methods described in previous chapters. As conclusion, a detailed analysis, assessment of the results and their usefulness when put into practice is provided.
POF - polymer optical fibres
Mikulec, Matěj ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
This work focuses on polymer optical fiber (POF). It describes basic properties of polymer optical fibers, materials for production and methods of manufacturing processes. In following chapters are given individual fibers that vary different refractive indexes and diameter of fiber. Also there are analyse connectors which are used for joining. As very suitable solution for home installation seems to be using the system Optolock without connectors. In the work is also written several areas where it is possible to use the POF. It can break through in automotive industry, home networks or as a sensor. The practical part contains measuring polygon draft and FTTH proposal using POF for distribution system in the house, where P2P topology is choosen. It´s also made a proposal for distribution of POF in the apartment. For installation in the apartment prices of network components are compared between POF distribution and UTP cat.6 cabling. UTP cat.6 is in this comparison many times more cheaply. Final chapter evaluate demands on work with POF fibers. Describes preparation of fiber before communication and creation of small experimental network. Important findings of the work are summarized in the conclusion.
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.
Solution deployment of DWDM systems 100G and 400G
Grenar, David ; Münster, Petr (referee) ; Filka, Miloslav (advisor)
The aim of this master´s thesis is an explanation of the problem of transport optical networks with Dense Wavelength Division Multiplexing. DWDM principle, properties and limit of transmission system. Focus of thesis is also specification properties of migration transmission system to higher speed 40G, 100G and in future to 400G. Part of thesis is outlined the basic division of multiplexing system, there are discussed the basic solutions of wavelength multiplexes CWDM and DWDM, focus for the effects of nonlinear phenomena and parasitic modulation FWM, SPM and XPM in modulation DP-QPSK and 16-QAM. In practicle part we will make measurement of properties of 10G and then experimental measurement parameters on 100G.
Methodology for designing PON networks
Dallal, Anas Omar ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Cílem této práce je analyzovat současný stav přístupových optických sítí,a hlouběji prozkoumat PON metodiku a návrh sítě. Navrhnul jsem síť založenou na konceptu FTTH pro 90 rodinných domů ovládané z centrální stanice vzdálené 20 km. Zabýval jsem se problémy při návrhu FTTH, konkrétně pasivní optickou sítí. Dále jsem se zabýval ATM-PON a Ethernet PON (EPON), které jsou založeny na společné síťové architektuře, PON, ale používají jiné přenosové technologie na podporu integrovaných služeb a jiné protokoly. Po zadání (optimálního) síťového řešení, které se hodí pro nabídku Triple-Play služeb. Dále budu popisovat, jak fungují síťová propojení a také budou popsány metody měření a testování navržené sítě "po aktivaci a nastavení sítě" a "před aktivací síťových služeb ". Při měření jsem také používal OTDR a prakticky ověřil charakteristiku linky. V práci je také naznačeno monitorování optické sítě.
Optical Amplifiers
Mlejnek, Zbyněk ; Křepelka, Václav (referee) ; Filka, Miloslav (advisor)
Optical amplifiers has sparked a revolution in the telecommunications industry during th last ten years. Optical amplifiers are devices that amplifies an optical signal directly, without the need to first convert it to an electrical signal. Its ability to provide low-noise amplification over a range of wavelengths, fortuitously correspoding to the low-loss of silica fiber, has made optical networks economically attractive

National Repository of Grey Literature : 201 records found   beginprevious86 - 95nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.