|
|
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.
|
|
|
"Gentlemen, please, take of your hats": Methods of dating and interpretation of photographies from years 1850–1918 through historical mens fashion
Polách, Radek
„GENTLEMEN, PLEASE, TAKE OFF YOUR HATS“ – Methods of dating and interpretation of photographies from years 1850-1918 through historical mens fashion is compacted material for professional description of historical photographic material from noblemens collection funds based on basic knowledge of mens and partially child fashion, and related clothing accessories. In its entirety it brings a large amount of knowledge from history of the then mens fashion, which was after the downfall of the Austro-Hungarian empire overlooked or presented only in narrowly specialized sections, e.g. in the military section. A large part of this publication is based not only on the knowledge of description of mens clothing, but mainly of headwear. It is this clothing accessory that is pivotal to the observed era, and with a closer look, it can help accurately date and describe people captured on historical photographs. It is primarily meant for the specialized staff of memory institutions of Czech Republic, who deal with these given issues. At the same though, it can allow curators and owners of historical funds a way to describe collections of exhibits that are kept in their collection funds.
Fulltext:  PDF
|
|
|
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.
|
guest ::
