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Top hat beam in free space optics
Golda, Martin ; Wilfert, Otakar (referee) ; Hudcová, Lucie (advisor)
This thesis describes a way of laser beam shaping of Gaussian profile to Top hat profile and the influence of atmospheric turbulences and attenuation on both these beam profiles. Its aim is to get acquainted oneself with a structure of atmosphere, principle of optical radiation which is used in free space communication and the influence of atmosphere on laser beam. To be successful in creation of beam with Top hat profile is necessary to study the principle of focusing by using the plano-convex lenses and other diffraction elements. This thesis compares the influence of atmospheric turbulences and attenuation between Gauss and Top hat beam results for two different wavelengths.
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Power Budget of the Laser Rangefinder
Kotol, Martin ; Němeček, Jiří (referee) ; Wilfert, Otakar (advisor)
The thesis analyzes the optical laser range finders in real propagation environments. Itdescribes the various parts of optical laser range finders their properties and principles in relation to their performance balance. The paper presents the basic optical properties of lenses used in the transmitter and receiver. A separate chapter is devoted to the transit time method and factors influencing the measurement. The proportional directional reflectance analysisis a part of the thesis. In conclusion, the thesis contains the practical laboratory measurements of the relative directional reflectance of different materials and colors, and verification of the power level diagram.
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Method of Atmospheric Transmission Media Characteristics Determination in Optical Spectrum
Hudcová, Lucie ; Lazar, Josef (referee) ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
This dissertation is focused on the determination of turbulent atmospheric transmission media properties. The concept of new method for turbulent attenuation designation is presented – the method of available power. This method comes from laser beam intensity profile analysis. The next point of this work is relative variance of optical intensity study. On the basis of experimental measurements relative variance of optical intensity is non-uniformly distributed in laser beam intensity profile. This non uniform distribution is subordinated to angular coefficient of intensity profile curve. Due to this information we can determine optimal laser beam shape to minimize influence of turbulent atmosphere.
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Influence of atmospheric turbulences on laser beam intensity profile
Císař, David ; Wilfert, Otakar (referee) ; Hudcová, Lucie (advisor)
Free space optical communications provide a reliable alternative to microwave and cable system applications. This technology is utilized for an optical links between ground stations, and moreover for links between High Altitude Platforms (HAPs). The main goal of the project is to gather knowledge about degradation of an optical beam in the atmosphere. The optical beam is being exposed to many factors such as intensity fluctuation based on turbulence, attenuation due to absorption and scattering. Furthermore, an emergence and influence of the atmospheric turbulences on the intensity profile of the laser beam are discussed. At the end, the methods of atmospheric turbulence measurement are given.
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Top hat beam in free space optics
Golda, Martin ; Wilfert, Otakar (referee) ; Hudcová, Lucie (advisor)
This thesis describes a way of laser beam shaping of Gaussian profile to Top hat profile and the influence of atmospheric turbulences and attenuation on both these beam profiles. Its aim is to get acquainted oneself with a structure of atmosphere, principle of optical radiation which is used in free space communication and the influence of atmosphere on laser beam. To be successful in creation of beam with Top hat profile is necessary to study the principle of focusing by using the plano-convex lenses and other diffraction elements. This thesis compares the influence of atmospheric turbulences and attenuation between Gauss and Top hat beam results for two different wavelengths.
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|
|
Method of Atmospheric Transmission Media Characteristics Determination in Optical Spectrum
Hudcová, Lucie ; Lazar, Josef (referee) ; Vlček, Čestmír (referee) ; Wilfert, Otakar (advisor)
This dissertation is focused on the determination of turbulent atmospheric transmission media properties. The concept of new method for turbulent attenuation designation is presented – the method of available power. This method comes from laser beam intensity profile analysis. The next point of this work is relative variance of optical intensity study. On the basis of experimental measurements relative variance of optical intensity is non-uniformly distributed in laser beam intensity profile. This non uniform distribution is subordinated to angular coefficient of intensity profile curve. Due to this information we can determine optimal laser beam shape to minimize influence of turbulent atmosphere.
|
|
| |
|
|
Influence of atmospheric turbulences on laser beam intensity profile
Císař, David ; Wilfert, Otakar (referee) ; Hudcová, Lucie (advisor)
Free space optical communications provide a reliable alternative to microwave and cable system applications. This technology is utilized for an optical links between ground stations, and moreover for links between High Altitude Platforms (HAPs). The main goal of the project is to gather knowledge about degradation of an optical beam in the atmosphere. The optical beam is being exposed to many factors such as intensity fluctuation based on turbulence, attenuation due to absorption and scattering. Furthermore, an emergence and influence of the atmospheric turbulences on the intensity profile of the laser beam are discussed. At the end, the methods of atmospheric turbulence measurement are given.
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