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Wireless optical link
Haňka, Jiří ; Hudcová, Lucie (referee) ; Poliak, Juraj (advisor)
This thesis is aimed at section of transmission of digital data by using two optical wireless communications realized by two free-space optics transcievers working in full-duplex mode. Generally, the work describes present options of optical connections, their principles and comparison with other connections. Basic components of realized transmitter and receiver are mentioned with their characteristics and wirings. The work describes options of transmission and further deals with various external events, which influence characteristics of transmitted optical signal. Thesis describes the optical part of design and construction free-space optic and it’s ending energy balance of this link. Further, the work treats of basic use of ethernet technology in transmissions, coding and modulations of data transmitted by optical connection.
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BIT ERROR RATE AND AVAILABILITY OF THE ATMOSPHERIC OPTICAL LINKS
Kvíčala, Radek ; Vašinek, Vladimír (referee) ; Fišer, Ondřej (referee) ; Wilfert, Otakar (advisor)
This dissertation deals with the problematic of the free space optical link availability determination. For the presumption of the free space optical link unavailability we have to know statistical distribution of the atmospheric attenuations. In this work is also presented the measurement of these atmospheric attenuations with the specially designed optical link. Measurement is using switching of the two separate transmitters with wavelengths of 830 nm and 1550 nm. Presented statistic distribution let us determine the suitability of the link in the chosen locality during its design. Comparison of our measurement with other models like model based on the meteorological visibility is also presented. The last part of this work is focused on the preconditions for the hi-speed network bit error rate determination. Sample of the bit error rate measurement obtained by our designed bit error rate tester is attached.
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Program for the optical link power budged calculation
Kováč, Martin ; Hudcová, Lucie (referee) ; Křivák, Petr (advisor)
Goal of this work is to study methodic of designing optical fiber and wireless link and to program an application which will be able to calculate power budget of specified link. Power budget of the link is the most important part of designing an optical fiber or wireless link because it tells us if it’s even possible to realize such connection or how many optical repeaters and amplifiers are needed. The bachelor thesis has three parts. The first part describes designing of optical fiber link (limitation by attenuation and dispersion) and various components that are needed (laser diode, optical fiber etc.). The second part describes designing of optical wireless link and atmospheric transfer environment (attenuation by beam spreading, attenuation by atmosphere and by turbulences in atmosphere). And finally the third part which is realization of the program for the optical link power budget calculation in compiler C++ Builder 6, flowchart, used equations and pictures (how does the application look like, how is it controlled and how the output may look like).
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Interferometric measurement of phase changes of optical beam in turbulence
Děcká, Klára ; Křivák,, Petr (referee) ; Hudcová, Lucie (advisor)
This master’s thesis deals with the impact of atmospheric turbulence on phase changes of a free space optical signal. This problematic is investigated by the interferometric method. A part of the thesis is focused on the phenomenon of atmospheric turbulence. Then the physical effect of interference is discussed and optical interferometers are described. The experimental part of the thesis is focused on measurement of phase shift of optical signal by interferometric method. The result of the thesis is to determine how phase shift of an optical beam depends on the strength of turbulence.
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Laser beam coherence in turbulent atmosphere
Polanský, David ; Drexler, Petr (referee) ; Hudcová, Lucie (advisor)
In the first part of the thesis discusses the function of the laser design and construction of its class. Here is an explanation of coherence and other properties of laser radiation. Listed below are the possibilities of energy distribution in the laser beam. Described in particular Gaussian beam. The paper explains the phenomena of bending and Young's experiment. The paper examines the influence of atmospheric environment in the transmission of electromagnetic waves, defined as light. Particular attention is devoted to atmospheric turbulence. In the second part are first discussed the possibility of measuring atmospheric turbulence and coherence of laser beam parameters. The following is designed to measure workplace coherence width and coherence length in a turbulent environment. At these workplaces were measured. The results of these measurements are also listed in the job. The following comparison of results with theoretical values.
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Low-range high-speed optical transceiver
Pučálka, Jan ; Tošovský, Petr (referee) ; Kubíček, Michal (advisor)
The diploma thesis deals with description and design of a low-cost free-space optical (FSO) link. First, general FSO theory is discussed including their common parameters, properties and topologies. Further, optical signal sources and detectors are proposed. Finally, the selected implementation is described including its design and realization. The proposed FSO consists of two identical segments (modules) to form a full-duplex link. The FSO utilizes LED as a light source, maximum speed data rate is 100 Mb/s with 100Base-TX interface.
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Influence of atmospheric turbulences on the optical beam
Bárta, Miroslav ; Wilfert, Otakar (referee) ; Hudcová, Lucie (advisor)
The aim of this thesis is to study a free space optics and its application in communication technologies. It describes possible interrupting impacts on the beamed optical signal, which are signal noise, attenuation of the atmosphere and atmospheric turbulence. The basis of the thesis is to describe the impact of the atmospheric turbulences on the optical beam. Fluctuation of optical intensity in the optical beam has been measured and index of refraction structure parameter calculated. With its assistance, turbulence rate has been determined.
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Interferometric measurement of phase changes of optical beam in turbulence
Děcká, Klára ; Křivák,, Petr (referee) ; Hudcová, Lucie (advisor)
This master’s thesis deals with the impact of atmospheric turbulence on phase changes of a free space optical signal. This problematic is investigated by the interferometric method. A part of the thesis is focused on the phenomenon of atmospheric turbulence. Then the physical effect of interference is discussed and optical interferometers are described. The experimental part of the thesis is focused on measurement of phase shift of optical signal by interferometric method. The result of the thesis is to determine how phase shift of an optical beam depends on the strength of turbulence.
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Wireless optical link
Haňka, Jiří ; Hudcová, Lucie (referee) ; Poliak, Juraj (advisor)
This thesis is aimed at section of transmission of digital data by using two optical wireless communications realized by two free-space optics transcievers working in full-duplex mode. Generally, the work describes present options of optical connections, their principles and comparison with other connections. Basic components of realized transmitter and receiver are mentioned with their characteristics and wirings. The work describes options of transmission and further deals with various external events, which influence characteristics of transmitted optical signal. Thesis describes the optical part of design and construction free-space optic and it’s ending energy balance of this link. Further, the work treats of basic use of ethernet technology in transmissions, coding and modulations of data transmitted by optical connection.
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BIT ERROR RATE AND AVAILABILITY OF THE ATMOSPHERIC OPTICAL LINKS
Kvíčala, Radek ; Vašinek, Vladimír (referee) ; Fišer, Ondřej (referee) ; Wilfert, Otakar (advisor)
This dissertation deals with the problematic of the free space optical link availability determination. For the presumption of the free space optical link unavailability we have to know statistical distribution of the atmospheric attenuations. In this work is also presented the measurement of these atmospheric attenuations with the specially designed optical link. Measurement is using switching of the two separate transmitters with wavelengths of 830 nm and 1550 nm. Presented statistic distribution let us determine the suitability of the link in the chosen locality during its design. Comparison of our measurement with other models like model based on the meteorological visibility is also presented. The last part of this work is focused on the preconditions for the hi-speed network bit error rate determination. Sample of the bit error rate measurement obtained by our designed bit error rate tester is attached.
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