Search for dissertations about: "beam"

Showing result 21 - 25 of 1389 swedish dissertations containing the word beam.

  2. 21. Direct Nanoprototyping of Functional Materials via Focused Electron Beam

    Author : Anastasia Riazanova; Lyubov M. Belova; Cornelis W. Hagen; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; EBID; nanoprototyping; nanopatterning; nanoscale; nanostructure; purification; Au; Co; SiO2; dimethyl gold acetylacetonate; dicobalt octacarbonyl; TEOS; Dual Beam;

    Abstract : During recent years the demand for nanoscale materials with tailor-made functional properties as bulk species, is continuously and progressively rising for such fields as e.g. micro- and nano-electronics, plasmonics, spintronics, bio-technology, bio-sensing and life sciences. READ MORE

  4. 22. Applications of Ion Beam Methods in Silicide/Si and Silicide/GaAs Nanometre Structures

    Author : Yanwen Zhang; Kärnfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Phase formation; Nanometre structures; silicide; detection efficiency; Ion Beam Analysis; Ion Beam Synthesis; Time-of-Flight Energy Elastic Recoil Detection ToF-E ERD ; implantation; Fysicumarkivet A:1998:Zhang; Kärnfysik; Nuclear physics; Detla E-E ERD;

    Abstract : Ion beam methods are used to analyse material (Ion Beam Analysis, IBA) and to modify the target (Ion Beam Modification of Materials, IBMM). In this thesis, ion beams have been used in various IBA techniques to investigate the surface nanometre structures, and also in an ion beam synthesis (IBS) technique to form thin films and to modify material properties. READ MORE

  5. 23. Propagation of some coherent and partially coherent laser beams

    Author : Yangjian Cai; Sailing He; Franco Gori; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; : dark hollow beam; elliptical Gaussian beam; flat-topped beam; twisted anisotropic Gaussian Schell-model; partial coherent; propagation; paraxial optical system; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Abstract : In this thesis, we investigate the propagation of some coherent and partially coherent laser beams, including a dark hollow beam (DHB), an elliptical Gaussian beam (EGB), a flat-topped beam and a twisted anisotropic Gaussian Schell-model (TAGSM) beam, through a paraxial optical system or a turbulent atmosphere. Several theoretical models are proposed to describe a DHB of circular or non-circular symmetry. READ MORE

  6. 24. Nematic Liquid Crystal Spatial Light Modulators for Laser Beam Steering

    Author : Emil Hällstig; Mikael Lindgren; Lars Sjöqvist; William Crossland; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; spatial light modulator; liquid crystal; beam steering; tracking; phase modulation; fringing field; director distribution; finite-difference time-domain; polarization; temporal properties; Fysik; Physics; Fysik;

    Abstract : Laser beam control is important in many applications. Phase modulating spatial light modulators (SLMs) can be used to electronically alter the phase distribution of an optical wave-front and thus change the direction and shape of a laser beam. READ MORE

  7. 25. Location-aided Beam Alignment and Handover in Millimeter-wave Networks

    Author : Sara Khosravi; Marina Petrova; Jens Zander; Sofie Pollin; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Millimeter wave networks; beam alignment; Handover; Reinforcement learning; Millimetervågnätverk; strålinriktning; överlämning; förstärkningsinlärning;

    Abstract : Ever-increasing data rate demands in mobile networks and the spectrum scarcity at the microwave bands have resulted in the exploration of millimeter-wave (mmWave) frequencies for the next generation of wireless networks. While mmWave frequencies offer large bandwidth, communication at these frequencies is not straightforward due to the challenging propagation characteristics. READ MORE