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Visar resultat 1 - 5 av 6 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Methods of Multi-Conjugate Adaptive Optics for Astronomy

   Författare :Ralf Flicker; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Adaptive optics; anisoplanatism; laser guide stars; performance estimation; wavefront reconstruction; extremely large telescopes; optics; Electromagnetism; Elektromagnetism; acoustics; Astronomy; akustik; space research; optik; multi-conjugate; cosmic chemistry; Astronomi; rymdvetenskap; kosmisk kemi; Fysicumarkivet A:2003:Flicker;

   Sammanfattning : This work analyses several aspects of multi-conjugate adaptive optics (MCAO) for astronomy. The research ranges from fundamental and technical studies for present-day MCAO projects, to feasibility studies of high-order MCAO instruments for the extremely large telescopes (ELTs) of the future. LÄS MER

3. 2. Extremely Large Telescopes Optical Design and Wavefront Correction

   Författare :Alexander Gontcharov; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; akustik; optik; Adaptive Optics; Extremely Large Telescopes; optical design methods; wavefront correction methods.; Electromagnetism; optics; Elektromagnetism; acoustics; space research; cosmic chemistry; Astronomi; rymdvetenskap; kosmisk kemi;

   Sammanfattning : An overview of the state of art within optical design of large astronomical telescopes is given. Recent advances within the field are presented. The importance of new computer-controlled mirror-polishing methods is emphasized. LÄS MER

4. 3. Algorithms for Coherent Diffractive Imaging with X-ray Lasers

   Författare :Benedikt J. Daurer; Filipe Maia; Tomas Ekeberg; Janos Hajdu; Richard Neutze; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; X-ray lasers; coherent diffractive imaging; algorithms; lensless imaging; flash diffractive imaging; flash X-ray imaging; aerosol injection; FEL; XFEL; CXI; CDI; FXI; Physics with specialization in Biophysics; Fysik med inriktning mot biofysik;

   Sammanfattning : Coherent diffractive imaging (CDI) has become a very popular technique over the past two decades. CDI is a "lensless" imaging method which replaces the objective lens of a conventional microscope by a computational image reconstruction procedure. LÄS MER

5. 4. Focusing properties of attosecond pulses

   Författare :Maria Hoflund; Atomfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The discovery of high-order harmonic generation (HHG) has made it possible to see the electron dynamics on their natural time scale, attoseconds. In the HHG process, a femtosecond infrared (IR) laser pulse is converted into a train of attosecond pulses in the extreme ultraviolet (XUV), but with a very low conversion efficiency. LÄS MER

7. 5. 3D localization in digital holography from scattered light from micrometer-sized particles

   Författare :Johan Öhman; Mikael Sjödahl; Per Bergström; Erik Olsson; Torbjörn Löfqvist; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Digital Holography; Polarization; Particle Scattering; Metrology; Experimentell mekanik; Experimental Mechanics;

   Sammanfattning : When a particle is illuminated by a beam of light it will scatter and redistribute the light in all directions. How it scatters depends on the size, shape and refractive index of the particle. Additionally, it depends on the wavelength and polarization of the illuminating beam. LÄS MER