Sökning: "circular polarization"

Visar resultat 1 - 5 av 40 avhandlingar innehållade orden circular polarization.

  1. 1. Advanced Antenna Systems for Fully Polarimetric Radar in Automotive Scenario

    Författare :Zhaorui Zang; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; circular polarization; gap waveguide; Antenna; dual circular polarization; automotive radar; polarimetric radar;

    Sammanfattning : The increasing dependence on Advanced Driver Assistance Systems (ADAS) highlights the critical need for fast target recognition, effective collision avoidance, cruise control, lane assistance, etc. This necessitates a significant advancement in sensor technology, particularly for accurate target classification and road surface sensing. LÄS MER

  3. 2. Mode and Polarization Control in VCSELs using Surface Structures

    Författare :Åsa Haglund; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; single mode; dynamics; surface relief; Semiconductor laser; polarization; vertical-cavity surface-emitting laser; sub-wavelength grating; fabrication;

    Sammanfattning : The vertical-cavity surface-emitting laser (VCSEL) is a novel, low-cost light source with many attractive performance characteristics, such as low operating current, circular output beam, and high modulation bandwidth at low currents. This together with its easy integration into two-dimensional arrays has made it an established transmitter in short-distance single and parallel fiber-optical links, and new applications are continuously arising. LÄS MER

  4. 3. Calculations on the possibilities for photoionization-delay studies with circularly polarized light

    Författare :Johanna Sörngård; Eva Lindroth; Markus Kowalewski; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attosecond physics; photoionization delay; circular polarization; Theoretical Physics; teoretisk fysik;

    Sammanfattning : Advances in experimental physics, specifically light sources emitting at an attosecond time scale, has enabled the time resolution of atomic processes like photoionization. Recent developments have allowed these sources to produce light with non-linear polarization. LÄS MER

  5. 4. Magnetism and Structure of Thin 3d Transition Metal Films : XMCD and EXAFS using Polarized Soft X-Rays

    Författare :Anders Hahlin; Dimitri Arvanitis; Olof Karis; Claus Schneider; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; thin film; xmcd; exafs; anisotropy; coherence; circular polarization; magnetism; Fe; Co; Ag; Fysik; Physics; Fysik; Fysik; Physics;

    Sammanfattning : In this Thesis the magnetic and structural properties of thin epitaxial Fe, Co, and Ni films are discussed. Some of the in-situ prepared samples were used to characterize the degree of circular polarization of the newly installed beamline D1011 at MAX-lab. LÄS MER

  7. 5. Optical spectroscopy of InGaAs quantum dots

    Författare :Arvid Larsson; Per Olof Holtz; Artur Zrenner; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; quantum dot; semiconductor; optical properties; spin; transport; wetting layer; polarization; kvantprick; halvledare; optiska egenskaper; spin; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik; Materials science; Teknisk materialvetenskap; Condensed matter physics; Kondenserade materiens fysik; Semiconductor physics; Halvledarfysik;

    Sammanfattning : The work presented in this thesis deals with optical studies of semiconductor quantum dots (QDs) in the InGaAs material system. It is shown that for self-assembled InAs QDs, the interaction with the surrounding GaAs barrier and the InAs wetting layer (WL) in particular, has a very large impact on their optical properties. LÄS MER